Hi The simple answer is that a ~ $100 Chinese GPSDO and a ~ $20 MiniCircuits power splitter (all off of eBay) should be able to drive a couple of counters and a few other pieces of gear.
If they are all “power on” when the bench is in use, daisy chain from the “important” stuff to the less accurate gear is fine. Indeed this adds to the maintenance checks while reducing the cost of the distribution hardware. ( = no free lunch). For normal lab use, the GPSDO output will do fine and it will be more accurate than normal bench gear. There’s also the “cool kid” factor :). The 10 MHz output can be provided for members to cal their gear against. One advantage of the GPSDO approach is that the rest of the bench can be fully shut down when nobody is around. A simple timer could do the job without anybody needing to remember this or that switch. The power savings from shutting the bench down fully will easily pay for the GPSDO in under a year ….. Bob > On Jan 5, 2020, at 1:29 PM, Robert DiRosario <[email protected]> wrote: > > I'm back, sorry for the delayed response. > > My understands is in the HP 5340A counter (all HP counters?) the 10544 or > 10811 always has power, regardless of the power switch, as long as it is > plugged in. Everything at our work bench is always plugged in. > > History > We (the radio club) have three HP 5340A counters, two 5345A counters and an > HP 106B. We took one of the 5340As and the 106B to the building with the Cs > standard in a minivan with a 12V to 120V inverter. The 106B had a good > battery pack, but it was still powered with the inverter. The first test was > to put 10 MHz from the Cs standard into the counter, and it read 10000000. > MHz. We moved on to plan B, we put the output of the OCXO into a counter > what was driven by the Cs standard. The error was less then 0.1 Hz. We made > a little change to the 10811 and moved on to the 106. The error on the 5 MHz > output was again less than 0.1 Hz, we made a small change to it. We ate our > lunch and moved the counter cable back and forth between the 5340A and 106B > and watched them. They both stabilized. 20 years latter, I don't recall what > the final error was. It was much better than any piece of ham gear anyone > would have. > > In 2011 the club got relocated to three mobile home trailers. They have HVAC > wall-packs, so we have Heat and AC 24/7 year-round. > Before the move the HVAC in the one room building that housed our work bench > and VHF station stopped working. The 106 also stopped working. I started > looking at a GPSDO after the move. I picked up some 10811s and Navman > Jupiter TU modules with 10 KHz output, but other projects came along and I > lost interest in this. > > Today: > This fall at a hamfest I got a working TrueTime XL-DC with antenna and > feedline for $45, it has 1 ppp and IRIG-B, but no 10 MHz output. This > restarted my interest in this project. Then I got some complaints from other > club members that our HP Modulation Analyzer was both off frequency and the > deviation measurement it was giving was also wrong. > > The first goal is to have fun and learn something new. > > At the club we have 3 5340As (18 GHz), the 53131A (225 MHz), a pair of > 5435As that don't work, and the 106B that doesn't work. > The goal is to have a calibrated standard to drive all of our test equipment. > It should be accurate and precise enough to allow club members to calibrate > their own equipment. That would point to a GPSDO. A 10811 for start, the > 106 if I can fix it. > > At home I have several HP counters, 5340A (18 GHz), 5341A (4.5 GHz), 5385A (1 > GHz), 5386A (3 GHz) and a 5334B (100 MHz, dual channel, sill do TI), but none > are calibrated. I have a NI HPIB card I need to get working. I have a HP > Z3801A that I need to get a power supply for. I have several 10811s, a pair > of 105Bs, a Trimble 57963 board, and the simple complete Trimble 57963 > system. I also have a Brooks Shera board that is built, I have some > connectors for it on the way. > > I have a full set of time-nut toys to play with! My view is I have no known > working primary standards yet, so I'm starting from scratch. > I need to compare the Trimble GPSDO to something else. The Z3801A or Brooks > Shera's board controlling a 10811 or one of the 105Bs. > > Thanks > > Robert > > On 12/26/2019 11:51 PM, Robert DiRosario wrote: >> I am trying to calibrate some equipment at the amateur radio club at work, >> and my stuff. We have an HP 5340A with a 10811 inside. It must have been >> upgraded at some point in the past, the display uses Nixie tubes. I >> calibrated it c2000 using a HP Cs standard. That lab and it's equipment are >> gone. :-( >> >> From ebay / China I got a simple GPSDO that uses a Trimble 57963 inside. I >> use the output of the 10811 in the 5340A to drive an HP 53131A. I then >> measured the 10 MHz output of the GPSDO using the HP 53131A and got >> 10,000,000.08 Hz. >> >> Assuming the GPSDO is correct, is 0.08 Hz drift over 20 years a reasonable >> amount of drift for an 10811? >> >> I have an HP Z3801A, once I get a power supply for it I can check the other >> GPSDO. >> >> Thanks >> >> Robert >> KA3ZYX >> >> __________________ > > On 12/26/2019 11:51 PM, Robert DiRosario wrote: >> I am trying to calibrate some equipment at the amateur radio club at work, >> and my stuff. We have an HP 5340A with a 10811 inside. It must have been >> upgraded at some point in the past, the display uses Nixie tubes. I >> calibrated it c2000 using a HP Cs standard. That lab and it's equipment are >> gone. :-( >> >> From ebay / China I got a simple GPSDO that uses a Trimble 57963 inside. I >> use the output of the 10811 in the 5340A to drive an HP 53131A. I then >> measured the 10 MHz output of the GPSDO using the HP 53131A and got >> 10,000,000.08 Hz. >> >> Assuming the GPSDO is correct, is 0.08 Hz drift over 20 years a reasonable >> amount of drift for an 10811? >> >> I have an HP Z3801A, once I get a power supply for it I can check the other >> GPSDO. >> >> Thanks >> >> Robert >> KA3ZYX >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > On 12/26/2019 11:51 PM, Robert DiRosario wrote: >> I am trying to calibrate some equipment at the amateur radio club at work, >> and my stuff. We have an HP 5340A with a 10811 inside. It must have been >> upgraded at some point in the past, the display uses Nixie tubes. I >> calibrated it c2000 using a HP Cs standard. That lab and it's equipment are >> gone. :-( >> >> From ebay / China I got a simple GPSDO that uses a Trimble 57963 inside. I >> use the output of the 10811 in the 5340A to drive an HP 53131A. I then >> measured the 10 MHz output of the GPSDO using the HP 53131A and got >> 10,000,000.08 Hz. >> >> Assuming the GPSDO is correct, is 0.08 Hz drift over 20 years a reasonable >> amount of drift for an 10811? >> >> I have an HP Z3801A, once I get a power supply for it I can check the other >> GPSDO. >> >> Thanks >> >> Robert >> KA3ZYX >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
