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Discussion of precise time and frequency measurement

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USB over optical fiber

DV
David Van Horn
Tue, Dec 3, 2019 12:54 PM

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com>
SM
Scott McGrath
Wed, Dec 4, 2019 7:14 AM

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DV
David Van Horn
Wed, Dec 4, 2019 6:51 PM

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
SM
Scott McGrath
Thu, Dec 5, 2019 4:16 AM

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DV
David Van Horn
Thu, Dec 5, 2019 1:15 PM

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Ok, thanks for the info. My unit should be arriving today or tomorrow. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 9:16 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DV
David Van Horn
Fri, Dec 6, 2019 1:21 PM

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Well, it arrived, and it is NOISY. ☹ It's pushing out longitudinal noise along the cable, and it's deafening my receiver. After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire. https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David Van Horn via time-nuts Sent: Thursday, December 5, 2019 6:15 AM To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Ok, thanks for the info. My unit should be arriving today or tomorrow. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 9:16 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
SM
Scott McGrath
Fri, Dec 6, 2019 1:28 PM

Wow,  cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn david.vanhorn@backcountryaccess.com wrote:

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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Wow, cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC > On Dec 6, 2019, at 3:21 PM, David Van Horn <david.vanhorn@backcountryaccess.com> wrote: > Well, it arrived, and it is NOISY. ☹ It's pushing out longitudinal noise along the cable, and it's deafening my receiver. After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire. https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David Van Horn via time-nuts Sent: Thursday, December 5, 2019 6:15 AM To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Ok, thanks for the info. My unit should be arriving today or tomorrow. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 9:16 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DV
David Van Horn
Fri, Dec 6, 2019 2:51 PM

It might pass class A or even B, but it totally obliterates the signals I'm looking for down at 457kHz.  The noise is pumped longitudinally along the "optical cable" and the metallic one to the product, which pretty much confirms a boost or flyback regulator making up for the voltage drop in the long thin wires.

Fortunately I have another one arriving today which does NOT have metallic conductors in the cable.  I'll need 5V to power the downstream end, but I can do that with D cells and an LDO if I have to.  Can't get much more quiet than that.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn david.vanhorn@backcountryaccess.com
Cc: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn david.vanhorn@backcountryaccess.com wrote:

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

It might pass class A or even B, but it totally obliterates the signals I'm looking for down at 457kHz. The noise is pumped longitudinally along the "optical cable" and the metallic one to the product, which pretty much confirms a boost or flyback regulator making up for the voltage drop in the long thin wires. Fortunately I have another one arriving today which does NOT have metallic conductors in the cable. I'll need 5V to power the downstream end, but I can do that with D cells and an LDO if I have to. Can't get much more quiet than that. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Friday, December 6, 2019 6:29 AM To: David Van Horn <david.vanhorn@backcountryaccess.com> Cc: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Subject: Re: [time-nuts] USB over optical fiber Wow, cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC > On Dec 6, 2019, at 3:21 PM, David Van Horn <david.vanhorn@backcountryaccess.com> wrote: > Well, it arrived, and it is NOISY. ☹ It's pushing out longitudinal noise along the cable, and it's deafening my receiver. After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire. https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David Van Horn via time-nuts Sent: Thursday, December 5, 2019 6:15 AM To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Ok, thanks for the info. My unit should be arriving today or tomorrow. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 9:16 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DV
David Van Horn
Fri, Dec 6, 2019 3:04 PM

This is my backup plan:
https://industrialcomponent.com/opticis/opm210003.html

The docs are a bit chinglish, but I'm encouraged by the fact that the distal end needs external power.  I was hoping the corning one was powering the distal end by CW laser of maybe 200mW with data carried on other wavelengths, or modulation of the power laser, but NOPE, just copper wires.  That one's packed up and ready to go back right now.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn david.vanhorn@backcountryaccess.com
Cc: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn david.vanhorn@backcountryaccess.com wrote:

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface.

That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and similar have an advantage in an open lab.  For permanent installation in raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts time-nuts@lists.febo.com wrote:

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.commailto:david.vanhorn@backcountryaccess.com

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

This is my backup plan: https://industrialcomponent.com/opticis/opm210003.html The docs are a bit chinglish, but I'm encouraged by the fact that the distal end needs external power. I was hoping the corning one was powering the distal end by CW laser of maybe 200mW with data carried on other wavelengths, or modulation of the power laser, but NOPE, just copper wires. That one's packed up and ready to go back right now. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Friday, December 6, 2019 6:29 AM To: David Van Horn <david.vanhorn@backcountryaccess.com> Cc: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Subject: Re: [time-nuts] USB over optical fiber Wow, cost cutting at work I have the corning one but its 3 years old Remember when FCC certification meant something for EMC > On Dec 6, 2019, at 3:21 PM, David Van Horn <david.vanhorn@backcountryaccess.com> wrote: > Well, it arrived, and it is NOISY. ☹ It's pushing out longitudinal noise along the cable, and it's deafening my receiver. After doing some research this morning, it appears that they do the DATA optically but power is taken on copper wires, and I'm betting a boost switcher to compensate for the voltage drop in the 28 ga wire. https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf I have another candidate arriving today which will require a 5V supply inside the cage, but I can do that with batteries and a linear regulator, much quieter. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David Van Horn via time-nuts Sent: Thursday, December 5, 2019 6:15 AM To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Ok, thanks for the info. My unit should be arriving today or tomorrow. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 9:16 PM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber You may still have a problem, That said most of your noise power is going to come from your USB device itself and perhaps the power supply That said ive never really had a problem doing similar testing using small chambers from ETS-Lindgren and similar vendors using the Corning interface. That said i’d recommend you go a step up to the Newnex and similar devices they are 3x the price but the fiber interlink is just a standard fiber LC-LC patch cord. With the low cost interface crimp its cable once accidentally you are buying a new one. With the newnex you are buying a 20-30 dollar patch cord. All that said performance is the same in the end but the newnex and similar have an advantage in an open lab. For permanent installation in raceway the cost advantage is with the one piece units. Content by Scott Typos by Siri > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I'm not too worried up there, my receivers are working at 457 kHz. -----Original Message----- From: Scott McGrath <scmcgrath@gmail.com> Sent: Wednesday, December 4, 2019 12:14 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: David Van Horn <david.vanhorn@backcountryaccess.com> Subject: Re: [time-nuts] USB over optical fiber Its not so much the noise from the interface its the USB device itself i’d worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly strong signals in the 2.4 GHz ISM band. Content by Scott Typos by Siri > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: > I suppose this is vaguely time-nutty. 😊 I have an application where I need to take USB into an EMC faraday cage. I see a number of optical fiber implementations available, and the prices ($200-300) are acceptable, but I’m worried about noise that the downstream end may cause, since it will need to be inside the cage. Does anyone have experience with these? Ones to stay away from? -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO 80301 USA phone: 303-417-1345 x110 email: david.vanhorn@backcountryaccess.com<mailto:david.vanhorn@backcountryaccess.com> _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
DW
Dana Whitlow
Fri, Dec 6, 2019 5:10 PM

Even without any funny business with boost converters (or whatever). those
copper wires
make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is
well-shielded, which
you did not mention.

I suppose it's too late to ask, but did you perhance try adding some
clamp-on ferrite chokes
to the cable?

Dana

On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts <
time-nuts@lists.febo.com> wrote:

This is my backup plan:
https://industrialcomponent.com/opticis/opm210003.html

The docs are a bit chinglish, but I'm encouraged by the fact that the
distal end needs external power.  I was hoping the corning one was
powering the distal end by CW laser of maybe 200mW with data carried on
other wavelengths, or modulation of the power laser, but NOPE, just copper
wires.  That one's packed up and ready to go back right now.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn david.vanhorn@backcountryaccess.com
Cc: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old
Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn <

Well, it arrived, and it is NOISY.  ☹
It's pushing out longitudinal noise along the cable, and it's deafening my
receiver.

After doing some research this morning, it appears that they do the DATA
optically but power is taken on copper wires, and I'm betting a boost
switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply
inside the cage, but I can do that with batteries and a linear regulator,
much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David Van
Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time and
frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is going
to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using small
chambers from ETS-Lindgren and similar vendors using the Corning
interface.

That said i’d recommend you go a step up to the Newnex and similar devices
they are 3x the price but the fiber interlink is just a standard fiber
LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are
buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and
similar have an advantage in an open lab.  For permanent installation in
raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts <

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d
worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has
fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the prices
($200-300) are acceptable, but I’m worried about noise that the downstream
end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com<mailto:
david.vanhorn@backcountryaccess.com>

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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To unsubscribe, go to
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and follow the instructions there.

Even without any funny business with boost converters (or whatever). those copper wires make a nice antenna for coupling noise from both ends (PC and USB accessory) into the environment inside the chamber. Unless, of course, the cable is well-shielded, which you did not mention. I suppose it's too late to ask, but did you perhance try adding some clamp-on ferrite chokes to the cable? Dana On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < time-nuts@lists.febo.com> wrote: > This is my backup plan: > https://industrialcomponent.com/opticis/opm210003.html > > The docs are a bit chinglish, but I'm encouraged by the fact that the > distal end needs external power. I was hoping the corning one was > powering the distal end by CW laser of maybe 200mW with data carried on > other wavelengths, or modulation of the power laser, but NOPE, just copper > wires. That one's packed up and ready to go back right now. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Friday, December 6, 2019 6:29 AM > To: David Van Horn <david.vanhorn@backcountryaccess.com> > Cc: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Subject: Re: [time-nuts] USB over optical fiber > > Wow, cost cutting at work I have the corning one but its 3 years old > Remember when FCC certification meant something for EMC > > > > > > > On Dec 6, 2019, at 3:21 PM, David Van Horn < > david.vanhorn@backcountryaccess.com> wrote: > > > > Well, it arrived, and it is NOISY. ☹ > It's pushing out longitudinal noise along the cable, and it's deafening my > receiver. > > After doing some research this morning, it appears that they do the DATA > optically but power is taken on copper wires, and I'm betting a boost > switcher to compensate for the voltage drop in the 28 ga wire. > > https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf > > > > I have another candidate arriving today which will require a 5V supply > inside the cage, but I can do that with batteries and a linear regulator, > much quieter. > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David Van > Horn via time-nuts > Sent: Thursday, December 5, 2019 6:15 AM > To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time and > frequency measurement <time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Ok, thanks for the info. My unit should be arriving today or tomorrow. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 9:16 PM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > You may still have a problem, That said most of your noise power is going > to come from your USB device itself and perhaps the power supply > > That said ive never really had a problem doing similar testing using small > chambers from ETS-Lindgren and similar vendors using the Corning > interface. > > That said i’d recommend you go a step up to the Newnex and similar devices > they are 3x the price but the fiber interlink is just a standard fiber > LC-LC patch cord. > > With the low cost interface crimp its cable once accidentally you are > buying a new one. > > With the newnex you are buying a 20-30 dollar patch cord. > > All that said performance is the same in the end but the newnex and > similar have an advantage in an open lab. For permanent installation in > raceway the cost advantage is with the one piece units. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I'm not too worried up there, my receivers are working at 457 kHz. > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 12:14 AM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Its not so much the noise from the interface its the USB device itself i’d > worry about as USB 3.0 generates RF signals up to 3 GHz. And also has > fairly strong signals in the 2.4 GHz ISM band. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I suppose this is vaguely time-nutty. 😊 > > I have an application where I need to take USB into an EMC faraday cage. > I see a number of optical fiber implementations available, and the prices > ($200-300) are acceptable, but I’m worried about noise that the downstream > end may cause, since it will need to be inside the cage. > > Does anyone have experience with these? Ones to stay away from? > > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com<mailto: > david.vanhorn@backcountryaccess.com> > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. >
DV
David Van Horn
Fri, Dec 6, 2019 8:17 PM

It's not shielded, and ferrites are pretty useless down here.
I did try, but the ferrites I have did nothing.

My backup plan arrives supposedly in the next 2 hours....

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of Dana Whitlow
Sent: Friday, December 6, 2019 10:10 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Subject: Re: [time-nuts] USB over optical fiber

Even without any funny business with boost converters (or whatever). those copper wires make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is well-shielded, which you did not mention.

I suppose it's too late to ask, but did you perhance try adding some clamp-on ferrite chokes to the cable?

Dana

On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < time-nuts@lists.febo.com> wrote:

This is my backup plan:
https://industrialcomponent.com/opticis/opm210003.html

The docs are a bit chinglish, but I'm encouraged by the fact that the
distal end needs external power.  I was hoping the corning one was
powering the distal end by CW laser of maybe 200mW with data carried
on other wavelengths, or modulation of the power laser, but NOPE, just copper
wires.  That one's packed up and ready to go back right now.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn david.vanhorn@backcountryaccess.com
Cc: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old
Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn <

Well, it arrived, and it is NOISY.  ☹ It's pushing out longitudinal
noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the
DATA optically but power is taken on copper wires, and I'm betting a
boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply
inside the cage, but I can do that with batteries and a linear
regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David
Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time
and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is
going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using
small chambers from ETS-Lindgren and similar vendors using the Corning
interface.

That said i’d recommend you go a step up to the Newnex and similar
devices they are 3x the price but the fiber interlink is just a
standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are
buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and
similar have an advantage in an open lab.  For permanent installation in
raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts <

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d
worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has
fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the
prices
($200-300) are acceptable, but I’m worried about noise that the
downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com<mailto:
david.vanhorn@backcountryaccess.com>

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go
to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go
to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
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time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

It's not shielded, and ferrites are pretty useless down here. I did try, but the ferrites I have did nothing. My backup plan arrives supposedly in the next 2 hours.... -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of Dana Whitlow Sent: Friday, December 6, 2019 10:10 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Subject: Re: [time-nuts] USB over optical fiber Even without any funny business with boost converters (or whatever). those copper wires make a nice antenna for coupling noise from both ends (PC and USB accessory) into the environment inside the chamber. Unless, of course, the cable is well-shielded, which you did not mention. I suppose it's too late to ask, but did you perhance try adding some clamp-on ferrite chokes to the cable? Dana On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < time-nuts@lists.febo.com> wrote: > This is my backup plan: > https://industrialcomponent.com/opticis/opm210003.html > > The docs are a bit chinglish, but I'm encouraged by the fact that the > distal end needs external power. I was hoping the corning one was > powering the distal end by CW laser of maybe 200mW with data carried > on other wavelengths, or modulation of the power laser, but NOPE, just copper > wires. That one's packed up and ready to go back right now. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Friday, December 6, 2019 6:29 AM > To: David Van Horn <david.vanhorn@backcountryaccess.com> > Cc: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Subject: Re: [time-nuts] USB over optical fiber > > Wow, cost cutting at work I have the corning one but its 3 years old > Remember when FCC certification meant something for EMC > > > > > > > On Dec 6, 2019, at 3:21 PM, David Van Horn < > david.vanhorn@backcountryaccess.com> wrote: > > > > Well, it arrived, and it is NOISY. ☹ It's pushing out longitudinal > noise along the cable, and it's deafening my receiver. > > After doing some research this morning, it appears that they do the > DATA optically but power is taken on copper wires, and I'm betting a > boost switcher to compensate for the voltage drop in the 28 ga wire. > > https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf > > > > I have another candidate arriving today which will require a 5V supply > inside the cage, but I can do that with batteries and a linear > regulator, much quieter. > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David > Van Horn via time-nuts > Sent: Thursday, December 5, 2019 6:15 AM > To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time > and frequency measurement <time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Ok, thanks for the info. My unit should be arriving today or tomorrow. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 9:16 PM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > You may still have a problem, That said most of your noise power is > going to come from your USB device itself and perhaps the power supply > > That said ive never really had a problem doing similar testing using > small chambers from ETS-Lindgren and similar vendors using the Corning > interface. > > That said i’d recommend you go a step up to the Newnex and similar > devices they are 3x the price but the fiber interlink is just a > standard fiber LC-LC patch cord. > > With the low cost interface crimp its cable once accidentally you are > buying a new one. > > With the newnex you are buying a 20-30 dollar patch cord. > > All that said performance is the same in the end but the newnex and > similar have an advantage in an open lab. For permanent installation in > raceway the cost advantage is with the one piece units. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 10:07 PM, Davida Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I'm not too worried up there, my receivers are working at 457 kHz. > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 12:14 AM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Its not so much the noise from the interface its the USB device itself i’d > worry about as USB 3.0 generates RF signals up to 3 GHz. And also has > fairly strong signals in the 2.4 GHz ISM band. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I suppose this is vaguely time-nutty. 😊 > > I have an application where I need to take USB into an EMC faraday cage. > I see a number of optical fiber implementations available, and the > prices > ($200-300) are acceptable, but I’m worried about noise that the > downstream end may cause, since it will need to be inside the cage. > > Does anyone have experience with these? Ones to stay away from? > > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com<mailto: > david.vanhorn@backcountryaccess.com> > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
J
jimlux
Fri, Dec 6, 2019 8:50 PM

On 12/6/19 9:10 AM, Dana Whitlow wrote:

Even without any funny business with boost converters (or whatever). those
copper wires
make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is
well-shielded, which
you did not mention.

I suppose it's too late to ask, but did you perhance try adding some
clamp-on ferrite chokes
to the cable?

We had a similar problem doing some testing on hardware in a EMI/EMC
chamber where we wanted to measure fields well below the MIL-STD-461
RE102 limits at HF frequencies.

Get some 31 mix toroids in the 2.4" diameter, and you can get a lot of
turns of the cable through it and the hole is big enough to clear most
connectors.  There are also clamp-on forms.  31 mix has a nice wide
range, although I don't know if it goes down to 100kHz.. there might be
a better mix.
You definitely don't want the usual VHF suppression mixes like 43 or 61.
But maybe mix 78, which is optimized for <2MHz

In this kind of application you want to look at mu'' (the lossy part of
permeability) as well as mu' (the non lossy part)

Or, as you plan to do, run stuff off batteries.

On 12/6/19 9:10 AM, Dana Whitlow wrote: > Even without any funny business with boost converters (or whatever). those > copper wires > make a nice antenna for coupling noise from both ends (PC and USB > accessory) into > the environment inside the chamber. Unless, of course, the cable is > well-shielded, which > you did not mention. > > I suppose it's too late to ask, but did you perhance try adding some > clamp-on ferrite chokes > to the cable? > We had a similar problem doing some testing on hardware in a EMI/EMC chamber where we wanted to measure fields well below the MIL-STD-461 RE102 limits at HF frequencies. Get some 31 mix toroids in the 2.4" diameter, and you can get a lot of turns of the cable through it and the hole is big enough to clear most connectors. There are also clamp-on forms. 31 mix has a nice wide range, although I don't know if it goes down to 100kHz.. there might be a better mix. You definitely don't want the usual VHF suppression mixes like 43 or 61. But maybe mix 78, which is optimized for <2MHz In this kind of application you want to look at mu'' (the lossy part of permeability) as well as mu' (the non lossy part) Or, as you plan to do, run stuff off batteries.
JC
J. Cordaro
Tue, Dec 10, 2019 6:36 AM

David,
I have used Pontis EMC USB converters and they worked meaning they had good radiated immunity and radiated emissions were below CISPR25 levels even in the 150kHz - 30MHz band.  
hvtechnologies is the US distributor.

My first EMC certification test at low frequencies was a humbling experience due to the noise from the switching power supply.  At $7.50 per minute we went with stacks of AA batteries in parallel.  
regards,Jay Cordaro

On Friday, December 6, 2019, 03:48:18 PM PST, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote:

It's not shielded, and ferrites are pretty useless down here.
I did try, but the ferrites I have did nothing.

My backup plan arrives supposedly in the next 2 hours....

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com 

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of Dana Whitlow
Sent: Friday, December 6, 2019 10:10 AM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Subject: Re: [time-nuts] USB over optical fiber

Even without any funny business with boost converters (or whatever). those copper wires make a nice antenna for coupling noise from both ends (PC and USB
accessory) into
the environment inside the chamber.  Unless, of course, the cable is well-shielded, which you did not mention.

I suppose it's too late to ask, but did you perhance try adding some clamp-on ferrite chokes to the cable?

Dana

On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < time-nuts@lists.febo.com> wrote:

This is my backup plan:
https://industrialcomponent.com/opticis/opm210003.html

The docs are a bit chinglish, but I'm encouraged by the fact that the
distal end needs external power.  I was hoping the corning one was
powering the distal end by CW laser of maybe 200mW with data carried
on other wavelengths, or modulation of the power laser, but NOPE, just copper
wires.  That one's packed up and ready to go back right now.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Friday, December 6, 2019 6:29 AM
To: David Van Horn david.vanhorn@backcountryaccess.com
Cc: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Subject: Re: [time-nuts] USB over optical fiber

Wow,  cost cutting at work I have the corning one but its 3 years old
Remember when FCC certification meant something for EMC

On Dec 6, 2019, at 3:21 PM, David Van Horn <

Well, it arrived, and it is NOISY.  ☹ It's pushing out longitudinal
noise along the cable, and it's deafening my receiver.

After doing some research this morning, it appears that they do the
DATA optically but power is taken on copper wires, and I'm betting a
boost switcher to compensate for the voltage drop in the 28 ga wire.

https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf

I have another candidate arriving today which will require a 5V supply
inside the cage, but I can do that with batteries and a linear
regulator, much quieter.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of David
Van Horn via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath scmcgrath@gmail.com; Discussion of precise time
and frequency measurement time-nuts@lists.febo.com
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Ok, thanks for the info.  My unit should be arriving today or tomorrow.

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 9:16 PM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

You may still have a problem,  That said most of your noise power is
going to come from your USB device itself and perhaps the power supply

That said ive never really had a problem doing similar testing using
small chambers from ETS-Lindgren and similar vendors using the Corning
interface.

That said i’d recommend you go a step up to the Newnex and similar
devices they are 3x the price but the fiber interlink is just a
standard fiber LC-LC patch cord.

With the low cost interface crimp its cable once accidentally you are
buying a new one.

With the newnex you are buying a 20-30 dollar patch cord.

All that said performance is the same in the end but the newnex and
similar have an advantage in an open lab.  For permanent installation in
raceway the cost advantage is with the one piece units.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts <

I'm not too worried up there, my receivers are working at 457 kHz.

-----Original Message-----
From: Scott McGrath scmcgrath@gmail.com
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc: David Van Horn david.vanhorn@backcountryaccess.com
Subject: Re: [time-nuts] USB over optical fiber

Its not so much the noise from the interface its the USB device itself i’d
worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has
fairly strong signals in the 2.4 GHz ISM band.

Content by Scott
Typos by Siri

On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts <

I suppose this is vaguely time-nutty. 😊

I have an application where I need to take USB into an EMC faraday cage.
I see a number of optical fiber implementations available, and the
prices
($200-300) are acceptable, but I’m worried about noise that the
downstream end may cause, since it will need to be inside the cage.

Does anyone have experience with these?  Ones to stay away from?

--
David VanHorn
Lead Hardware Engineer

Backcountry Access, Inc.
2820 Wilderness Pl, Unit H
Boulder, CO  80301 USA
phone: 303-417-1345  x110
email: david.vanhorn@backcountryaccess.com<mailto:
david.vanhorn@backcountryaccess.com>

time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go
to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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and follow the instructions there.

David, I have used Pontis EMC USB converters and they worked meaning they had good radiated immunity and radiated emissions were below CISPR25 levels even in the 150kHz - 30MHz band.   hvtechnologies is the US distributor. My first EMC certification test at low frequencies was a humbling experience due to the noise from the switching power supply.  At $7.50 per minute we went with stacks of AA batteries in parallel.   regards,Jay Cordaro On Friday, December 6, 2019, 03:48:18 PM PST, David Van Horn via time-nuts <time-nuts@lists.febo.com> wrote: It's not shielded, and ferrites are pretty useless down here. I did try, but the ferrites I have did nothing. My backup plan arrives supposedly in the next 2 hours.... -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO  80301 USA phone: 303-417-1345  x110 email: david.vanhorn@backcountryaccess.com  -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of Dana Whitlow Sent: Friday, December 6, 2019 10:10 AM To: Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Subject: Re: [time-nuts] USB over optical fiber Even without any funny business with boost converters (or whatever). those copper wires make a nice antenna for coupling noise from both ends (PC and USB accessory) into the environment inside the chamber.  Unless, of course, the cable is well-shielded, which you did not mention. I suppose it's too late to ask, but did you perhance try adding some clamp-on ferrite chokes to the cable? Dana On Fri, Dec 6, 2019 at 10:05 AM David Van Horn via time-nuts < time-nuts@lists.febo.com> wrote: > This is my backup plan: > https://industrialcomponent.com/opticis/opm210003.html > > The docs are a bit chinglish, but I'm encouraged by the fact that the > distal end needs external power.  I was hoping the corning one was > powering the distal end by CW laser of maybe 200mW with data carried > on other wavelengths, or modulation of the power laser, but NOPE, just copper > wires.  That one's packed up and ready to go back right now. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO  80301 USA > phone: 303-417-1345  x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Friday, December 6, 2019 6:29 AM > To: David Van Horn <david.vanhorn@backcountryaccess.com> > Cc: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Subject: Re: [time-nuts] USB over optical fiber > > Wow,  cost cutting at work I have the corning one but its 3 years old > Remember when FCC certification meant something for EMC > > > > > > > On Dec 6, 2019, at 3:21 PM, David Van Horn < > david.vanhorn@backcountryaccess.com> wrote: > > > > Well, it arrived, and it is NOISY.  ☹ It's pushing out longitudinal > noise along the cable, and it's deafening my receiver. > > After doing some research this morning, it appears that they do the > DATA optically but power is taken on copper wires, and I'm betting a > boost switcher to compensate for the voltage drop in the 28 ga wire. > > https://www.corning.com/microsites/coc/ocbc/Documents/CNT-075-AEN.pdf > > > > I have another candidate arriving today which will require a 5V supply > inside the cage, but I can do that with batteries and a linear > regulator, much quieter. > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO  80301 USA > phone: 303-417-1345  x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of David > Van Horn via time-nuts > Sent: Thursday, December 5, 2019 6:15 AM > To: Scott McGrath <scmcgrath@gmail.com>; Discussion of precise time > and frequency measurement <time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Ok, thanks for the info.  My unit should be arriving today or tomorrow. > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO  80301 USA > phone: 303-417-1345  x110 > email: david.vanhorn@backcountryaccess.com > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 9:16 PM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > You may still have a problem,  That said most of your noise power is > going to come from your USB device itself and perhaps the power supply > > That said ive never really had a problem doing similar testing using > small chambers from ETS-Lindgren and similar vendors using the Corning > interface. > > That said i’d recommend you go a step up to the Newnex and similar > devices they are 3x the price but the fiber interlink is just a > standard fiber LC-LC patch cord. > > With the low cost interface crimp its cable once accidentally you are > buying a new one. > > With the newnex you are buying a 20-30 dollar patch cord. > > All that said performance is the same in the end but the newnex and > similar have an advantage in an open lab.  For permanent installation in > raceway the cost advantage is with the one piece units. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 10:07 PM, Davida  Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I'm not too worried up there, my receivers are working at 457 kHz. > > -----Original Message----- > From: Scott McGrath <scmcgrath@gmail.com> > Sent: Wednesday, December 4, 2019 12:14 AM > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > Cc: David Van Horn <david.vanhorn@backcountryaccess.com> > Subject: Re: [time-nuts] USB over optical fiber > > Its not so much the noise from the interface its the USB device itself i’d > worry about as USB 3.0 generates RF signals up to 3 GHz.  And also has > fairly strong signals in the 2.4 GHz ISM band. > > Content by Scott > Typos by Siri > > > On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > I suppose this is vaguely time-nutty. 😊 > > I have an application where I need to take USB into an EMC faraday cage. > I see a number of optical fiber implementations available, and the > prices > ($200-300) are acceptable, but I’m worried about noise that the > downstream end may cause, since it will need to be inside the cage. > > Does anyone have experience with these?  Ones to stay away from? > > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO  80301 USA > phone: 303-417-1345  x110 > email: david.vanhorn@backcountryaccess.com<mailto: > david.vanhorn@backcountryaccess.com> > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
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