[time-nuts] Re: Turning off display on HP 58503 A or B
Chris, Thanks for the reply. I have made just such a mod to one of my 58503's. It was in a discussion of this mod that the idea arose that HP had built in such a command. But, no one had actual knowledge of such this hidden command. It was most probably just wishful thinking. Thanks again for your comments. 73 de Lon , K5JV On Mon, Jun 6, 2022 at 11:33 PM Chris Hastreiter via time-nuts < time-nuts@lists.febo.com> wrote: > I'm not aware of any command to turn off the display - I haven't seen it in > the manual, but I think that it might use the same display interface as the > 53131A counter. For that unit I've added a two pole switch that allows me > to turn off the anode and filament voltages to the display when I'm not > using it. You could measure the voltages on your interface cable and see > if it matches the 53131A schematic and if so do something similar. > > Chris > > On Fri, Jun 3, 2022 at 5:47 PM K5jv via time-nuts < > time-nuts@lists.febo.com> > wrote: > > > I was recently evolved in a discussion about the HP 58503 option 001 > > display. The general idea is that there is some command to tune the > > display on or off. A few ideas were offered but no one had anything > except > > "they heard about it." I have found nothing on the subject from old HP > > literature. Comments would be appreciated. I am not talking about > turning > > the power off to the DC/DC converter. > > > > On a different subject: A couple of month back I got some strong > > criticism about suggesting that the oven in the Z3801A was a potential > > source of problems. I just got another Z3801A in for repair. Same > > symptoms as before; appears to turn on normally but after a while goes > > into holdover and stay there, same LH flat lines. Once again the > problem > > turned out to be the oven. It was unusually hot to the touch. Changing > > the oven solved the problem. Now my question. I have never opened one > of > > these oven, so have no real idea exactly what is inside. I would > suspect > > that one of the oven's thermostats is stuck in the "on" position. Since > > it is a "double oven", there could be two thermostats? If these are > > mechanical contacts, as one might expect fro the 1995 era, can they be > > cleaned or replaced? Comments from anyone who has actually seen inside > > one of these ovens would be appreciated. > > > > > > 73 de Lon, K5JV > > 281-795-1335 > > > > > > [a96323c7-47c0-46b2-8018-f039618476d5] > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Turning off display on HP 58503 A or B
I'm not aware of any command to turn off the display - I haven't seen it in the manual, but I think that it might use the same display interface as the 53131A counter. For that unit I've added a two pole switch that allows me to turn off the anode and filament voltages to the display when I'm not using it. You could measure the voltages on your interface cable and see if it matches the 53131A schematic and if so do something similar. Chris On Fri, Jun 3, 2022 at 5:47 PM K5jv via time-nuts wrote: > I was recently evolved in a discussion about the HP 58503 option 001 > display. The general idea is that there is some command to tune the > display on or off. A few ideas were offered but no one had anything except > "they heard about it." I have found nothing on the subject from old HP > literature. Comments would be appreciated. I am not talking about turning > the power off to the DC/DC converter. > > On a different subject: A couple of month back I got some strong > criticism about suggesting that the oven in the Z3801A was a potential > source of problems. I just got another Z3801A in for repair. Same > symptoms as before; appears to turn on normally but after a while goes > into holdover and stay there, same LH flat lines. Once again the problem > turned out to be the oven. It was unusually hot to the touch. Changing > the oven solved the problem. Now my question. I have never opened one of > these oven, so have no real idea exactly what is inside. I would suspect > that one of the oven's thermostats is stuck in the "on" position. Since > it is a "double oven", there could be two thermostats? If these are > mechanical contacts, as one might expect fro the 1995 era, can they be > cleaned or replaced? Comments from anyone who has actually seen inside > one of these ovens would be appreciated. > > > 73 de Lon, K5JV > 281-795-1335 > > > [a96323c7-47c0-46b2-8018-f039618476d5] > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Turning off display on HP 58503 A or B
Am 2022-06-02 19:55, schrieb K5jv via time-nuts: On a different subject: A couple of month back I got some strong criticism about suggesting that the oven in the Z3801A was a potential source of problems. I just got another Z3801A in for repair. Same symptoms as before; appears to turn on normally but after a while goes into holdover and stay there, same LH flat lines. Once again the problem turned out to be the oven. It was unusually hot to the touch. Changing the oven solved the problem. Now my question. I have never opened one of these oven, so have no real idea exactly what is inside. I would suspect that one of the oven's thermostats is stuck in the "on" position. Since it is a "double oven", there could be two thermostats? If these are mechanical contacts, as one might expect fro the 1995 era, can they be cleaned or replaced? Comments 1965 ??? from anyone who has actually seen inside one of these ovens would be appreciated. I had a Morion MV-89A that stopped oscillating when the tune voltage was > 0.8V. I opened it and recovered the SC 5 MHz crystal. It had parameters that could be expected from such a crystal, quite good. The xtal parameters were not too different between room temperature and 85°C, stability obviously excluded. It is possible to do most development work for a new oscillator without burning one's fingers too often. There is one thermistor in the inner oven; in the outer oven there is probably sth. else, but nothing mechanical. < https://www.flickr.com/photos/137684711@N07/49585174873/in/album-72157662535945536/ > and from there to the right. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Turning off display on HP 58503 A or B
Lon, K5JV said: > Comments from anyone who has actually seen inside one of these ovens would be > appreciated. http://www.realhamradio.com/GPS-oven-journey.htm -- For lots of info on the Z3801A start here: http://www.realhamradio.com/GPS_Frequency_Standard.htm (Time sink warning.) -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Turning off display on HP 58503 A or B
Hi Lon, hello to all members. In 1995 the art of temperature control was a good bit more advanced, and a bi-metal thermostat would not be stable enough These ovens have a semiconductor temperature control; so I would suspect a shorted transistor. These failures in OCXO are not that rare, and that is why there are thermal safety fuses. And please don't defeat them ! 73 from Claude VA2 HDD Le 02/06/2022 13:55, K5jv via time-nuts a écrit : CAUTION: This email originated from outside your organization. Exercise caution when opening attachments or on clicking links from unknown senders. I was recently evolved in a discussion about the HP 58503 option 001 display. The general idea is that there is some command to tune the display on or off. A few ideas were offered but no one had anything except "they heard about it." I have found nothing on the subject from old HP literature. Comments would be appreciated. I am not talking about turning the power off to the DC/DC converter. On a different subject: A couple of month back I got some strong criticism about suggesting that the oven in the Z3801A was a potential source of problems. I just got another Z3801A in for repair. Same symptoms as before; appears to turn on normally but after a while goes into holdover and stay there, same LH flat lines. Once again the problem turned out to be the oven. It was unusually hot to the touch. Changing the oven solved the problem. Now my question. I have never opened one of these oven, so have no real idea exactly what is inside. I would suspect that one of the oven's thermostats is stuck in the "on" position. Since it is a "double oven", there could be two thermostats? If these are mechanical contacts, as one might expect fro the 1995 era, can they be cleaned or replaced? Comments from anyone who has actually seen inside one of these ovens would be appreciated. 73 de Lon, K5JV 281-795-1335 [a96323c7-47c0-46b2-8018-f039618476d5] ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Turning off display on HP 58503 A or B
Hi Both control loops in the 3801 OCXO’s are thermistor based. If the outside loop goes nuts, the device might survive. If the inside loop shorts out, the normal result is a melt down of the OCXO innards. Bob > On Jun 2, 2022, at 9:55 AM, K5jv via time-nuts > wrote: > > I was recently evolved in a discussion about the HP 58503 option 001 display. > The general idea is that there is some command to tune the display on or > off. A few ideas were offered but no one had anything except "they heard > about it." I have found nothing on the subject from old HP literature. > Comments would be appreciated. I am not talking about turning the power off > to the DC/DC converter. > > On a different subject: A couple of month back I got some strong criticism > about suggesting that the oven in the Z3801A was a potential source of > problems. I just got another Z3801A in for repair. Same symptoms as > before; appears to turn on normally but after a while goes into holdover and > stay there, same LH flat lines. Once again the problem turned out to be the > oven. It was unusually hot to the touch. Changing the oven solved the > problem. Now my question. I have never opened one of these oven, so have no > real idea exactly what is inside. I would suspect that one of the oven's > thermostats is stuck in the "on" position. Since it is a "double oven", > there could be two thermostats? If these are mechanical contacts, as one > might expect fro the 1995 era, can they be cleaned or replaced? Comments > from anyone who has actually seen inside one of these ovens would be > appreciated. > > > 73 de Lon, K5JV > 281-795-1335 > > > [a96323c7-47c0-46b2-8018-f039618476d5] > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
