Empathy List Archives

MD

Magnus Danielson

Sat, Nov 20, 2010 11:49 AM

Fellow time-nuts,

Björn and I have been having some fun during our get-together in his
basement time-lab. I pulled with me some gear (CNT-90 and SR620) for him
to play with, so a good warmup exercise was to measure the offset
between the PPS and the clock output (5 MHz or 10 MHz).

The results was uhm... spread out... so we felt like sending you guys a
report.

First out was a RAPCO 1804M which has a HCD 66 SC 5 MHz oven diciplined
by an old Trimble SV6+ (?) GPS receiver. We popped the lid for other
purposes... :) It had the 5 MHz rising edge 32,17 ns behind the PPS
rising edge, with 100 ps RMS jitter. Quite noticeable offset but fair
jitter.

The good old RAPCO was jumperable to be on "OSC" or "GPS" on the
mysterious jumper LK9 and it was stuck hard on the "OSC" setting, but
some physical exercise later we got it into GPS setting and it had a
about 200 ns peak to peak sawtooth... nice and pedagogical exercise.

We then had a look at the Brandywine GPS-4 (mine on loan to Björn) and
found it had fairly nice numbers... until we discovered it has a
periodically reoccuring glitch of unknown system-source.

Natually we hooked in to Björns Thunderbolt and found the offset so
tight that we ran into trigger-problems, but offsetting the clock by
about 8 ns of coax cable we had a about 4 ns in average and 6 ns
peak-to-peak. The PPS thus jumped between two distinct offsets with
their respective gaussian distribution around them. Not all that neat,
and the RAPCO was the quietest in this shoot-out.

Over and out,
Magnus and Björn

Fellow time-nuts, Björn and I have been having some fun during our get-together in his basement time-lab. I pulled with me some gear (CNT-90 and SR620) for him to play with, so a good warmup exercise was to measure the offset between the PPS and the clock output (5 MHz or 10 MHz). The results was uhm... spread out... so we felt like sending you guys a report. First out was a RAPCO 1804M which has a HCD 66 SC 5 MHz oven diciplined by an old Trimble SV6+ (?) GPS receiver. We popped the lid for other purposes... :) It had the 5 MHz rising edge 32,17 ns behind the PPS rising edge, with 100 ps RMS jitter. Quite noticeable offset but fair jitter. The good old RAPCO was jumperable to be on "OSC" or "GPS" on the mysterious jumper LK9 and it was stuck hard on the "OSC" setting, but some physical exercise later we got it into GPS setting and it had a about 200 ns peak to peak sawtooth... nice and pedagogical exercise. We then had a look at the Brandywine GPS-4 (mine on loan to Björn) and found it had fairly nice numbers... until we discovered it has a periodically reoccuring glitch of unknown system-source. Natually we hooked in to Björns Thunderbolt and found the offset so tight that we ran into trigger-problems, but offsetting the clock by about 8 ns of coax cable we had a about 4 ns in average and 6 ns peak-to-peak. The PPS thus jumped between two distinct offsets with their respective gaussian distribution around them. Not all that neat, and the RAPCO was the quietest in this shoot-out. Over and out, Magnus and Björn

BC

Bob Camp

Sun, Nov 21, 2010 2:52 AM

Hi

Sounds like it's time to get a better counter

Bob

On Nov 20, 2010, at 6:49 AM, Magnus Danielson wrote:

Fellow time-nuts,

Björn and I have been having some fun during our get-together in his basement time-lab. I pulled with me some gear (CNT-90 and SR620) for him to play with, so a good warmup exercise was to measure the offset between the PPS and the clock output (5 MHz or 10 MHz).

The results was uhm... spread out... so we felt like sending you guys a report.

First out was a RAPCO 1804M which has a HCD 66 SC 5 MHz oven diciplined by an old Trimble SV6+ (?) GPS receiver. We popped the lid for other purposes... :) It had the 5 MHz rising edge 32,17 ns behind the PPS rising edge, with 100 ps RMS jitter. Quite noticeable offset but fair jitter.

The good old RAPCO was jumperable to be on "OSC" or "GPS" on the mysterious jumper LK9 and it was stuck hard on the "OSC" setting, but some physical exercise later we got it into GPS setting and it had a about 200 ns peak to peak sawtooth... nice and pedagogical exercise.

We then had a look at the Brandywine GPS-4 (mine on loan to Björn) and found it had fairly nice numbers... until we discovered it has a periodically reoccuring glitch of unknown system-source.

Natually we hooked in to Björns Thunderbolt and found the offset so tight that we ran into trigger-problems, but offsetting the clock by about 8 ns of coax cable we had a about 4 ns in average and 6 ns peak-to-peak. The PPS thus jumped between two distinct offsets with their respective gaussian distribution around them. Not all that neat, and the RAPCO was the quietest in this shoot-out.

Over and out,
Magnus and Björn

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Hi Sounds like it's time to get a better counter Bob On Nov 20, 2010, at 6:49 AM, Magnus Danielson wrote: > Fellow time-nuts, > > Björn and I have been having some fun during our get-together in his basement time-lab. I pulled with me some gear (CNT-90 and SR620) for him to play with, so a good warmup exercise was to measure the offset between the PPS and the clock output (5 MHz or 10 MHz). > > The results was uhm... spread out... so we felt like sending you guys a report. > > First out was a RAPCO 1804M which has a HCD 66 SC 5 MHz oven diciplined by an old Trimble SV6+ (?) GPS receiver. We popped the lid for other purposes... :) It had the 5 MHz rising edge 32,17 ns behind the PPS rising edge, with 100 ps RMS jitter. Quite noticeable offset but fair jitter. > > The good old RAPCO was jumperable to be on "OSC" or "GPS" on the mysterious jumper LK9 and it was stuck hard on the "OSC" setting, but some physical exercise later we got it into GPS setting and it had a about 200 ns peak to peak sawtooth... nice and pedagogical exercise. > > We then had a look at the Brandywine GPS-4 (mine on loan to Björn) and found it had fairly nice numbers... until we discovered it has a periodically reoccuring glitch of unknown system-source. > > Natually we hooked in to Björns Thunderbolt and found the offset so tight that we ran into trigger-problems, but offsetting the clock by about 8 ns of coax cable we had a about 4 ns in average and 6 ns peak-to-peak. The PPS thus jumped between two distinct offsets with their respective gaussian distribution around them. Not all that neat, and the RAPCO was the quietest in this shoot-out. > > Over and out, > Magnus and Björn > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

SW

Stan, W1LE

Sun, Nov 21, 2010 4:20 PM

Hello The Net:

Excess to my needs is a National Instruments model: GPIB 232CT 64K,
P/N: 180450-01 Rev B1

Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a
standalone box.

I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max.
I do not have any drivers or any documentation, which should be on the
NI website.

Connectors are for a female 25 pin D shell for the RS-232 and a female
GPIB connector.

Does it work ? I do not know.

Free to the first respondent who wants to pay the postage.
Should fit in one of those priority mail boxes with unlimited weight.

I grew up and got a Prologix USB to GPIB adapter and I have never looked
back.

Stan, W1LE Cape Cod FN41sr

ZZZZz

Hello The Net: Excess to my needs is a National Instruments model: GPIB 232CT 64K, P/N: 180450-01 Rev B1 Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a standalone box. I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max. I do not have any drivers or any documentation, which should be on the NI website. Connectors are for a female 25 pin D shell for the RS-232 and a female GPIB connector. Does it work ? I do not know. Free to the first respondent who wants to pay the postage. Should fit in one of those priority mail boxes with unlimited weight. I grew up and got a Prologix USB to GPIB adapter and I have never looked back. Stan, W1LE Cape Cod FN41sr ZZZZz

BC

Bob Camp

Sun, Nov 21, 2010 4:48 PM

Hi

These gizmos can be very useful when the counter is on one end of the room and the computer is 30+ feet away. They are a bit speed limited in that case, but for a reading a second - no problem.

Bob

On Nov 21, 2010, at 11:20 AM, Stan, W1LE wrote:

Hello The Net:

Excess to my needs is a National Instruments model: GPIB 232CT 64K, P/N: 180450-01 Rev B1

Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a standalone box.

I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max.
I do not have any drivers or any documentation, which should be on the NI website.

Connectors are for a female 25 pin D shell for the RS-232 and a female GPIB connector.

Does it work ? I do not know.

Free to the first respondent who wants to pay the postage.
Should fit in one of those priority mail boxes with unlimited weight.

I grew up and got a Prologix USB to GPIB adapter and I have never looked back.

Stan, W1LE Cape Cod FN41sr

ZZZZz

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Hi These gizmos can be very useful when the counter is on one end of the room and the computer is 30+ feet away. They are a bit speed limited in that case, but for a reading a second - no problem. Bob On Nov 21, 2010, at 11:20 AM, Stan, W1LE wrote: > Hello The Net: > > Excess to my needs is a National Instruments model: GPIB 232CT 64K, P/N: 180450-01 Rev B1 > > Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a standalone box. > > I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max. > I do not have any drivers or any documentation, which should be on the NI website. > > Connectors are for a female 25 pin D shell for the RS-232 and a female GPIB connector. > > Does it work ? I do not know. > > Free to the first respondent who wants to pay the postage. > Should fit in one of those priority mail boxes with unlimited weight. > > I grew up and got a Prologix USB to GPIB adapter and I have never looked back. > > Stan, W1LE Cape Cod FN41sr > > > > > ZZZZz > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

SW

Stan, W1LE

Sun, Nov 21, 2010 7:06 PM

Hello The Net:

The GPIB controller is spoken for.

Stan, W1LE

On 11/21/2010 11:20 AM, Stan, W1LE wrote:

Hello The Net:

Excess to my needs is a National Instruments model: GPIB 232CT 64K,
P/N: 180450-01 Rev B1

Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a
standalone box.

I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max.
I do not have any drivers or any documentation, which should be on the
NI website.

Connectors are for a female 25 pin D shell for the RS-232 and a female
GPIB connector.

Does it work ? I do not know.

Free to the first respondent who wants to pay the postage.
Should fit in one of those priority mail boxes with unlimited weight.

I grew up and got a Prologix USB to GPIB adapter and I have never
looked back.

Stan, W1LE Cape Cod FN41sr

ZZZZz

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Hello The Net: The GPIB controller is spoken for. Stan, W1LE On 11/21/2010 11:20 AM, Stan, W1LE wrote: > Hello The Net: > > Excess to my needs is a National Instruments model: GPIB 232CT 64K, > P/N: 180450-01 Rev B1 > > Looks to be a RS-232 to IEEE 488 controller (GPIB adapter) in a > standalone box. > > I do not have the wall wart power supply, but it uses +9VDC @ 700 mA max. > I do not have any drivers or any documentation, which should be on the > NI website. > > Connectors are for a female 25 pin D shell for the RS-232 and a female > GPIB connector. > > Does it work ? I do not know. > > Free to the first respondent who wants to pay the postage. > Should fit in one of those priority mail boxes with unlimited weight. > > I grew up and got a Prologix USB to GPIB adapter and I have never > looked back. > > Stan, W1LE Cape Cod FN41sr > > > > > ZZZZz > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

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PPS and 5/10 MHz GPSDO time relationship