time-nuts@lists.febo.com

Discussion of precise time and frequency measurement

View all threads

10 MHz 'failover' switch?

W
W7SLS
Thu, Jul 26, 2018 7:45 PM

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS

Hello, Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. Not really sure of the correct term. Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. Context: I have a GPSDO and a Rb source of 10 MHz. The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). I have a new power supply on order, but would be nice to have “insurance”. Thanks in advance for the group bandwidth. Scott W7SLS
BK
Bob kb8tq
Thu, Jul 26, 2018 8:13 PM

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Hi They are a pretty rare item. A more common approach is a disciplined oscillator that will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. The equally big problem will be getting doc’s on one if you do find it…. Bob > On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: > > Hello, > > Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. > > Not really sure of the correct term. > Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. > > A brief search showed several very nice $$$ items, suitable for commercial applications, > but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. > > Context: > > I have a GPSDO and a Rb source of 10 MHz. > The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). > I have a new power supply on order, but would be nice to have “insurance”. > > Thanks in advance for the group bandwidth. > > Scott > W7SLS > _______________________________________________ > 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.
W
W7SLS
Thu, Jul 26, 2018 8:59 PM

Hi Bob,

Thanks for the quick reply, makes sense.

73
Scott
W7SLS

On Jul 26, 2018, at 1:13 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS

Hi Bob, Thanks for the quick reply, makes sense. 73 Scott W7SLS > On Jul 26, 2018, at 1:13 PM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > They are a pretty rare item. A more common approach is a disciplined oscillator that > will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. > The equally big problem will be getting doc’s on one if you do find it…. > > Bob > >> On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: >> >> Hello, >> >> Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. >> >> Not really sure of the correct term. >> Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. >> >> A brief search showed several very nice $$$ items, suitable for commercial applications, >> but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. >> >> Context: >> >> I have a GPSDO and a Rb source of 10 MHz. >> The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). >> I have a new power supply on order, but would be nice to have “insurance”. >> >> Thanks in advance for the group bandwidth. >> >> Scott >> W7SLS
SM
Scott McGrath
Thu, Jul 26, 2018 9:33 PM

Build one yourself,  Detector diode on primary RF input when output drops use a rf relay or PIN diode switch to fail over to backup standard.    All thats needed is a crossing detector and relay / switch driver

Yes there would be a momentary hit but it would work.

Content by Scott
Typos by Siri

On Jul 26, 2018, at 4:13 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Build one yourself, Detector diode on primary RF input when output drops use a rf relay or PIN diode switch to fail over to backup standard. All thats needed is a crossing detector and relay / switch driver Yes there would be a momentary hit but it would work. Content by Scott Typos by Siri On Jul 26, 2018, at 4:13 PM, Bob kb8tq <kb8tq@n1k.org> wrote: Hi They are a pretty rare item. A more common approach is a disciplined oscillator that will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. The equally big problem will be getting doc’s on one if you do find it…. Bob > On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: > > Hello, > > Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. > > Not really sure of the correct term. > Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. > > A brief search showed several very nice $$$ items, suitable for commercial applications, > but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. > > Context: > > I have a GPSDO and a Rb source of 10 MHz. > The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). > I have a new power supply on order, but would be nice to have “insurance”. > > Thanks in advance for the group bandwidth. > > Scott > W7SLS > _______________________________________________ > 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.
BK
Bob kb8tq
Thu, Jul 26, 2018 9:45 PM

Hi

One interesting subtlety making something like this:

What if the two inputs aren’t quite on the same frequency?  Purely as an example, say they are 1 Hz off from each other.
If you have 60 db of isolation in your “switch” you get a 1 Hz offset spur that is 60 db down. Even something much further
down is plenty to mess up the ADEV of the output.

Bob

On Jul 26, 2018, at 4:33 PM, Scott McGrath scmcgrath@gmail.com wrote:

Build one yourself,  Detector diode on primary RF input when output drops use a rf relay or PIN diode switch to fail over to backup standard.    All thats needed is a crossing detector and relay / switch driver

Yes there would be a momentary hit but it would work.

Content by Scott
Typos by Siri

On Jul 26, 2018, at 4:13 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Hi One interesting subtlety making something like this: What if the two inputs aren’t quite on the same frequency? Purely as an example, say they are 1 Hz off from each other. If you have 60 db of isolation in your “switch” you get a 1 Hz offset spur that is 60 db down. Even something much further down is plenty to mess up the ADEV of the output. Bob > On Jul 26, 2018, at 4:33 PM, Scott McGrath <scmcgrath@gmail.com> wrote: > > Build one yourself, Detector diode on primary RF input when output drops use a rf relay or PIN diode switch to fail over to backup standard. All thats needed is a crossing detector and relay / switch driver > > Yes there would be a momentary hit but it would work. > > Content by Scott > Typos by Siri > > On Jul 26, 2018, at 4:13 PM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > They are a pretty rare item. A more common approach is a disciplined oscillator that > will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. > The equally big problem will be getting doc’s on one if you do find it…. > > Bob > >> On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: >> >> Hello, >> >> Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. >> >> Not really sure of the correct term. >> Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. >> >> A brief search showed several very nice $$$ items, suitable for commercial applications, >> but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. >> >> Context: >> >> I have a GPSDO and a Rb source of 10 MHz. >> The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). >> I have a new power supply on order, but would be nice to have “insurance”. >> >> Thanks in advance for the group bandwidth. >> >> Scott >> W7SLS >> _______________________________________________ >> 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.
VH
Van Horn, David
Thu, Jul 26, 2018 10:23 PM

Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch.
The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace.
So for any failure of the two live systems, all he had to do was flip the switch and call me.

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of W7SLS
Sent: Thursday, July 26, 2018 1:46 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] 10 MHz 'failover' switch?

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch. The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace. So for any failure of the two live systems, all he had to do was flip the switch and call me. -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of W7SLS Sent: Thursday, July 26, 2018 1:46 PM To: time-nuts@lists.febo.com Subject: [time-nuts] 10 MHz 'failover' switch? Hello, Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. Not really sure of the correct term. Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. Context: I have a GPSDO and a Rb source of 10 MHz. The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). I have a new power supply on order, but would be nice to have “insurance”. Thanks in advance for the group bandwidth. Scott W7SLS _______________________________________________ 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, Jul 26, 2018 10:40 PM

True but if you use a good switch or PIN 90 db of isolation is easily achievable.  Yes the spur is still there but it’s 90 down and will not affect ADEV as badly.

You could drive it further down with two switches with the alternate standard connected to 1 port and a termination to the other.  So a switchover would switch to the alternate port and the backup path would switch from termination to backup source.    This would easily buy you 120-130 db isolation assuming use of good cabling and proper routing, grounds etc

After all this IS time-nuts after all

Content by Scott
Typos by Siri

On Jul 26, 2018, at 6:23 PM, Van Horn, David david.vanhorn@backcountryaccess.com wrote:

Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch.
The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace.
So for any failure of the two live systems, all he had to do was flip the switch and call me.

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of W7SLS
Sent: Thursday, July 26, 2018 1:46 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] 10 MHz 'failover' switch?

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

True but if you use a good switch or PIN 90 db of isolation is easily achievable. Yes the spur is still there but it’s 90 down and will not affect ADEV as badly. You could drive it further down with two switches with the alternate standard connected to 1 port and a termination to the other. So a switchover would switch to the alternate port and the backup path would switch from termination to backup source. This would easily buy you 120-130 db isolation assuming use of good cabling and proper routing, grounds etc After all this IS time-nuts after all Content by Scott Typos by Siri On Jul 26, 2018, at 6:23 PM, Van Horn, David <david.vanhorn@backcountryaccess.com> wrote: Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch. The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace. So for any failure of the two live systems, all he had to do was flip the switch and call me. -----Original Message----- From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of W7SLS Sent: Thursday, July 26, 2018 1:46 PM To: time-nuts@lists.febo.com Subject: [time-nuts] 10 MHz 'failover' switch? Hello, Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. Not really sure of the correct term. Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. Context: I have a GPSDO and a Rb source of 10 MHz. The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). I have a new power supply on order, but would be nice to have “insurance”. Thanks in advance for the group bandwidth. Scott W7SLS _______________________________________________ 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.
BK
Bob kb8tq
Fri, Jul 27, 2018 12:36 AM

Hi

90 db will not drive the ADEV nuts, but it still will be a lot worse than a normal standard will deliver, even at
120 db down, if the offset is a bit above 1 Hz you will still see it in an ADEV plot.

Bob

On Jul 26, 2018, at 5:40 PM, Scott McGrath scmcgrath@gmail.com wrote:

True but if you use a good switch or PIN 90 db of isolation is easily achievable.  Yes the spur is still there but it’s 90 down and will not affect ADEV as badly.

You could drive it further down with two switches with the alternate standard connected to 1 port and a termination to the other.  So a switchover would switch to the alternate port and the backup path would switch from termination to backup source.    This would easily buy you 120-130 db isolation assuming use of good cabling and proper routing, grounds etc

After all this IS time-nuts after all

Content by Scott
Typos by Siri

On Jul 26, 2018, at 6:23 PM, Van Horn, David david.vanhorn@backcountryaccess.com wrote:

Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch.
The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace.
So for any failure of the two live systems, all he had to do was flip the switch and call me.

-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of W7SLS
Sent: Thursday, July 26, 2018 1:46 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] 10 MHz 'failover' switch?

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Hi 90 db will not drive the ADEV nuts, but it still will be a lot worse than a normal standard will deliver, even at 120 db down, if the offset is a bit above 1 Hz you will still see it in an ADEV plot. Bob > On Jul 26, 2018, at 5:40 PM, Scott McGrath <scmcgrath@gmail.com> wrote: > > True but if you use a good switch or PIN 90 db of isolation is easily achievable. Yes the spur is still there but it’s 90 down and will not affect ADEV as badly. > > You could drive it further down with two switches with the alternate standard connected to 1 port and a termination to the other. So a switchover would switch to the alternate port and the backup path would switch from termination to backup source. This would easily buy you 120-130 db isolation assuming use of good cabling and proper routing, grounds etc > > After all this IS time-nuts after all > > Content by Scott > Typos by Siri > > On Jul 26, 2018, at 6:23 PM, Van Horn, David <david.vanhorn@backcountryaccess.com> wrote: > > Not quite what you are looking for, but I implemented a pair of thunderbolts with no common parts (dual antennas power etc) into a simple RF switch. > The production manager flipped the switch on Mondays, and if either system wasn't working I had a third system in a box ready to replace. > So for any failure of the two live systems, all he had to do was flip the switch and call me. > > > -----Original Message----- > From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of W7SLS > Sent: Thursday, July 26, 2018 1:46 PM > To: time-nuts@lists.febo.com > Subject: [time-nuts] 10 MHz 'failover' switch? > > Hello, > > Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. > > Not really sure of the correct term. > Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. > > A brief search showed several very nice $$$ items, suitable for commercial applications, but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. > > Context: > > I have a GPSDO and a Rb source of 10 MHz. > The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). > I have a new power supply on order, but would be nice to have “insurance”. > > Thanks in advance for the group bandwidth. > > Scott > W7SLS > _______________________________________________ > 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, Jul 27, 2018 5:38 PM

Since this is time nuts ADEV is sacred,

but the question is the use case.

Are we looking at a time nuts level frequency distribution network. Or are we trying to lock benchtop instruments with poor internal standards to a common ‘Good’ reference.

If the former it can be done but will require a fair amount of design work as well as some EMC
Modeling of the system to ensure no feed through of unwanted signals and/or modulation or beat products

If the latter simple detection and switching will be sufficient but dual switch much better.

Content by Scott
Typos by Siri

On Jul 26, 2018, at 4:59 PM, W7SLS w7sls.scott@gmail.com wrote:

Hi Bob,

Thanks for the quick reply, makes sense.

73
Scott
W7SLS

On Jul 26, 2018, at 1:13 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Since this is time nuts ADEV is sacred, but the question is the use case. Are we looking at a time nuts level frequency distribution network. Or are we trying to lock benchtop instruments with poor internal standards to a common ‘Good’ reference. If the former it can be done but will require a fair amount of design work as well as some EMC Modeling of the system to ensure no feed through of unwanted signals and/or modulation or beat products If the latter simple detection and switching will be sufficient but dual switch much better. Content by Scott Typos by Siri On Jul 26, 2018, at 4:59 PM, W7SLS <w7sls.scott@gmail.com> wrote: Hi Bob, Thanks for the quick reply, makes sense. 73 Scott W7SLS > On Jul 26, 2018, at 1:13 PM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > They are a pretty rare item. A more common approach is a disciplined oscillator that > will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. > The equally big problem will be getting doc’s on one if you do find it…. > > Bob > >> On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: >> >> Hello, >> >> Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. >> >> Not really sure of the correct term. >> Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. >> >> A brief search showed several very nice $$$ items, suitable for commercial applications, >> but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. >> >> Context: >> >> I have a GPSDO and a Rb source of 10 MHz. >> The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). >> I have a new power supply on order, but would be nice to have “insurance”. >> >> Thanks in advance for the group bandwidth. >> >> Scott >> W7SLS _______________________________________________ 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.
BK
Bob kb8tq
Fri, Jul 27, 2018 9:06 PM

Hi

If you are feeding a frequency counter with the “10 MHz + spur” signal, it can indeed mess up the modern
computing counters.

Bob

On Jul 27, 2018, at 12:38 PM, Scott McGrath scmcgrath@gmail.com wrote:

Since this is time nuts ADEV is sacred,

but the question is the use case.

Are we looking at a time nuts level frequency distribution network. Or are we trying to lock benchtop instruments with poor internal standards to a common ‘Good’ reference.

If the former it can be done but will require a fair amount of design work as well as some EMC
Modeling of the system to ensure no feed through of unwanted signals and/or modulation or beat products

If the latter simple detection and switching will be sufficient but dual switch much better.

Content by Scott
Typos by Siri

On Jul 26, 2018, at 4:59 PM, W7SLS w7sls.scott@gmail.com wrote:

Hi Bob,

Thanks for the quick reply, makes sense.

73
Scott
W7SLS

On Jul 26, 2018, at 1:13 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

They are a pretty rare item. A more common approach is a disciplined oscillator that
will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find.
The equally big problem will be getting doc’s on one if you do find it….

Bob

On Jul 26, 2018, at 2:45 PM, W7SLS w7sls.scott@gmail.com wrote:

Hello,

Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution.

Not really sure of the correct term.
Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary.

A brief search showed several very nice $$$ items, suitable for commercial applications,
but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab.

Context:

I have a GPSDO and a Rb source of 10 MHz.
The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock).
I have a new power supply on order, but would be nice to have “insurance”.

Thanks in advance for the group bandwidth.

Scott
W7SLS


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.

Hi If you are feeding a frequency counter with the “10 MHz + spur” signal, it can indeed mess up the modern computing counters. Bob > On Jul 27, 2018, at 12:38 PM, Scott McGrath <scmcgrath@gmail.com> wrote: > > Since this is time nuts ADEV is sacred, > > but the question is the use case. > > Are we looking at a time nuts level frequency distribution network. Or are we trying to lock benchtop instruments with poor internal standards to a common ‘Good’ reference. > > If the former it can be done but will require a fair amount of design work as well as some EMC > Modeling of the system to ensure no feed through of unwanted signals and/or modulation or beat products > > If the latter simple detection and switching will be sufficient but dual switch much better. > > Content by Scott > Typos by Siri > > On Jul 26, 2018, at 4:59 PM, W7SLS <w7sls.scott@gmail.com> wrote: > > Hi Bob, > > Thanks for the quick reply, makes sense. > > 73 > Scott > W7SLS > >> On Jul 26, 2018, at 1:13 PM, Bob kb8tq <kb8tq@n1k.org> wrote: >> >> Hi >> >> They are a pretty rare item. A more common approach is a disciplined oscillator that >> will do failover on it’s inputs. That’s still a rare item, but at least a possible thing to find. >> The equally big problem will be getting doc’s on one if you do find it…. >> >> Bob >> >>> On Jul 26, 2018, at 2:45 PM, W7SLS <w7sls.scott@gmail.com> wrote: >>> >>> Hello, >>> >>> Looking for recommendation for a ‘failover’ or ‘redundant’ switch for 10 MHz distribution. >>> >>> Not really sure of the correct term. >>> Something that sensed RF on primary 10 MHz, and then switched to secondary on fail of primary. >>> >>> A brief search showed several very nice $$$ items, suitable for commercial applications, >>> but I wonder if there are some “last year’s” (but not last century) versions that would work for a home lab. >>> >>> Context: >>> >>> I have a GPSDO and a Rb source of 10 MHz. >>> The power supply on the GPSDO failed (worked enough to light up the GPSDO, but not enough to lock). >>> I have a new power supply on order, but would be nice to have “insurance”. >>> >>> Thanks in advance for the group bandwidth. >>> >>> Scott >>> W7SLS > > > _______________________________________________ > 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.