Re: [time-nuts] Oscilloquartz 3210 Cesium Standard
Hi Chris, Sorry for a delayed reply. The OSA 3210 is one of the only cesium standards I don't have in the "museum". I've seen one or two on eBay over the past decade but not in worthwhile condition. I hope you can get yours working. If not, let me know... The good news is that I have an original Oscilloquartz 3200 cesium manual. Today I scanned the first part of it for you. See: http://www.leapsecond.com/museum/osa3200/ If this is helpful to your efforts, I'll try to scan the schematics as well. The manual is an inch thick. I don't know the model differences. I've seen 3000, 3020 and 3200, 3210, 3230, 3235 mentioned on the web. Maybe 3120. I'm also not clear about the differences in series-3000 vs. series-3100 vs. series 3200. If anyone knows, please post details. Thanks, /tvb - Original Message - From: "Chris" To: Sent: Wednesday, August 27, 2014 2:09 PM Subject: [time-nuts] Oscilloquartz 3210 Cesium Standard > Hi, > > I recently bought an Oscilloquartz 3210 cesium standard and although it does > power up, it does not lock. All the parameters on the meter look > sensible, other > than the 2nd harmonic, #9 parameter, which shows zero. Quart oscillator > output > looks almost spot on in comparison with the lab Z3816. I have no info on > this > unit at all, so this may either be a dead tube, or other electronic fault on > one of the many pcb's in the system. Ion pump had a small reading on > power up, > but now dropped back to zero. > > I am looking for a user guide for this unit, or even better, a manual > with theory > of operation and setup info. Can anyone help with this, or perhaps suggest a > source ?. Year of manufacture estimated 1984/85, from date code on ic's. > > I notice that the tube is from FTS, the same construction as in the FTS > 4060, but > different part number and wonder if this was original fitment, or has been > replaced at some stage... > > Regards & Thanks > > Chris Quayle > > Oxford, England ___ 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.
Re: [time-nuts] 10811 Thermal fuse?
On 9/3/2014 12:23 PM, John Miles wrote: Was the oven in a runaway condition? Like Bob, I've never seen a situation where the thermal fuse has actually done anything useful. It seems like the inner oven will go into full-blown China Syndrome before the thermal fuse on the far side of the outer PCB gets hot enough to fail. -- john, KE5FX Miles Design LLC John, I have two now with open fuses; one where the thermistor went open and the thermal fuse did blow, and the other just the usual fatigue. So despite the layer of foam between the Oven part and the board it did get hot enough to blow in the one. With an open thermistor the oven stays full on. I am waiting on Digikey to deliver some 43 cent (in qty 10 plus postage) Panasonic 1A 115C fuses, so I should be good for my lifetime... I'd still rather fit these at that price rather than link it out even if the odds are minuscule... Dan ___ 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.
Re: [time-nuts] 10811 Thermal fuse?
> -Original Message- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of David > McGaw > Sent: Wednesday, September 03, 2014 8:01 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] 10811 Thermal fuse? > > Actually, in the unit in which the fuse had opened, it had protected the > unit when the thermistor failed open. Having seen this happen, I > recommend it be replaced. The Panasonic part is 63 cents. > > David Was the oven in a runaway condition? Like Bob, I've never seen a situation where the thermal fuse has actually done anything useful. It seems like the inner oven will go into full-blown China Syndrome before the thermal fuse on the far side of the outer PCB gets hot enough to fail. -- john, KE5FX Miles Design LLC ___ 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.
Re: [time-nuts] 10811 Thermal fuse?
Actually, in the unit in which the fuse had opened, it had protected the unit when the thermistor failed open. Having seen this happen, I recommend it be replaced. The Panasonic part is 63 cents. David On 9/3/14 7:33 AM, Bob Camp wrote: Hi In all the years I’ve been doing this, there have been a *lot* of posts and observations about that fuse failing. The number of reports / observations of that fuse doing what it is supposed to do (protect a failed controller) have been virtually zero. By far the easiest “replacement” is a piece of wire. The risk associated with this fix is near zero. Is it zero - no, but we spend far more money on these fuses than we would on a handful of replacement OCXO’s. Bob On Sep 3, 2014, at 5:29 AM, David McGaw wrote: Let's try this again: They are HP/Agilent/Keysight PN 10811-80008. I was actually able to buy a couple from Agilent a few years ago. They are listed as obsolete now. A Panasonic EYP2BH115 should fit. Newark has them. David On 9/2/14 8:05 PM, Dave Daniel wrote: I believe a thermal cut-out is a device which interrupts the circuit when a prescribed temperature is reached or exceeded (in some cases by heating from an increase in current through a conductor), but which re-connects the circuit once the temperature has dropped below the cut-out temperature (possibly with some hysteresis built in). A fuse, on the other hand, interrupts the circuit after a certain current threshold is exceeded (and, of course there is an increase in temperature related to the increase in current) but which is destroyed in the process out interrupting the circuit. DaveD On 9/2/2014 5:10 PM, Dan Rae wrote: On 9/2/2014 12:23 PM, Dan Rae wrote: I'm sure this has been discussed to death before, but does anyone know of a source of thermal fuses small enough to fit in the -hp- 10811? I have found plenty of larger ones, none of which will fit and would rather not just link it out. Dan ___ Thanks for all the tips and advice. The Chinese eBay ones (15A) I have bought before and they are physically too big to fit. Buerklin is a German distributor and will want 28 Euros to ship to the US. I know I can link it out, but don't like doing that in something that is powered on permanently. I have found some Panasonic ones that Digikey distribute in the US, but frustratingly the data sheets have no dimensions given. I have ordered some 1A and 2A ones to try, and will report further. I suspect that the originals would have been around 115C. And for searching they seem to be called Thermal Cut Outs (TCO), not fuses. Dan ___ 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. ___ 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. ___ 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. ___ 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. ___ 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.
Re: [time-nuts] OCXO Phase Noise Measurement in Primitive Conditions
Hi A lot depends on how good your OCXO is. 1) With a typical OCXO, the 1 second tau should be around 2x10^-11 against a typical Rb. You are limited by the Rb. 2) With a good reference and OCXO the 1 second tau should be about 10X better than that (2x10^-12). 3) With some OCXO’s you can do 5 to 10X better still. Keep in mind that for 1 you will need a ~10ps counter. For the other cases, forget about a counter. Typically things like DMTD’s and TimePod’s get used in these cases. Chances are, you are looking more at your counter and Rb than at your GPSDO. Bob On Sep 2, 2014, at 9:31 PM, Bob Stewart wrote: > Hi Bob, > > Thanks for the review. I thought I knew a good deal of that, and promptly > forgot it in the heat of battle. > > Here's a plot of about 8,000 samples vs my trusty FE-5680A. The blue is the > OCXO output vs the Rb as measured on my 5335A w/10811 clock. The red is the > OCXO vs corrected 1PPS as measured by the TIC in the GPSDO. As this is my > first one of these, I don't know what to make of it. The two lines > intersect, which I assume is the point where the OCXO stability gives way to > the GPSDO stability. But, is ~1E-9 a good starting point for this old > 34310-T, or is it an indication that there is some underlying problem that I > haven't addressed? Perhaps the ADC in the PIC? > > > http://evoria.net/AE6RV/TIC/ADEV4.png > > Bob > > > > > From: Bob Camp > To: Bob Stewart > Cc: Discussion of precise time and frequency measurement > Sent: Tuesday, September 2, 2014 5:39 PM > Subject: Re: [time-nuts] OCXO Phase Noise Measurement in Primitive Conditions > > > Hi > > There are a lot of GPSDO ADEV plots out there. The T-Bolt has a lot of plots > run on it, there are others. > > Ideally the plot should start out looking like an OCXO: > > 1) Left hand side rising as you go left. Rate of rise 1/Tau. > 2) Left hand side intersecting a flat region somewhere in the 0.1 to 1 second > range. > 3) Flat region running out to a few hundred or a few thousand seconds > 4) Rising region past the flat area more or less straight line as you go > further to the right. > > That’s what you start with before you have any GPS involved at all. The flat > region could be at 1.0 x 10^-11, it could be 10X, or 100X lower than that > depending on the OCXO you have. The flat region could run out to 1,000 > seconds at 1.0x10^-13 if you get really lucky. One way to measure all this is > to take two or three identical OCXO’s and compare them with a device capable > of < 1.0 x 10^-13 accuracy at one second tau. > > —— > > Now you have your GPS. Most modern GPS plots are pretty simple. You have an > error (say 2 ns) at one second. That gives you an ADEV of 2.0 x10^-9 at a tau > of 1 second. At 10 seconds the same error gives you an ADEV of 2.0 x10^-10. > At 100 seconds the same error gives you an ADEV of 2.0 x10^-11. It just keeps > on going down and down as tau gets longer. At some point it hits a floor and > then runs flat from there on. Depending on how you do your corrections the > floor is somewhere below 1.0x10^-13. > > —— > > Lay those two plots down on top of each other. > > An ideal GPSDO would have the best of both and only the best of both devices. > You would have the close in ADEV and flat area from the OCXO. You would then > hop on the falling plot of the GPS and ride it down to who knows where (let’s > say 1.0x10^-14). It would magically have no peaking or odd behavior (it’s > ideal). The closer you come to that ideal, the better your GPSDO is doing. > > —— > > In the real world we need to measure things like GPSDO’s. They can not be > measured against themselves. They need to be compared against something else. > Sorry, but there are no shortcuts. If you want to show how one is working, > you need a comparison standard. It can be a second GPSDO. It could be a > Hydrogen Maser. It might be a Cesium standard. What ever you use to do the > comparison must be up to the job. A counter with a 1 ns (or 100 ps) > resolution isn’t going to show you 1 second tau data on a good OCXO. > > Can you estimate what’s going on - sure. The gotcha is that you will never > know if your estimates are correct without a comparison. If you have made a > few hundred of these things, all done the same way, you probably can guess > pretty well. If you have a new design, first time up and running, your guess > may not be very good. > > —— > > Yes, that’s the short / abridged version. The full version goes on and on for > a few hundred pages. There are lots of special cases and a multitude of ways > to deal with each of them. There are also a number of end goals you can > target with a design. The optimum outcome will be different for each of the. > > Lots of Fun. > > Bob > > > > On Sep 2, 2014, at 12:02 PM, Bob Stewart wrote: > >> Hi Bob, >> >> I take it that the 3 segment ADEV pretty much defines a GPSD
Re: [time-nuts] 10811 Thermal fuse?
Hi In all the years I’ve been doing this, there have been a *lot* of posts and observations about that fuse failing. The number of reports / observations of that fuse doing what it is supposed to do (protect a failed controller) have been virtually zero. By far the easiest “replacement” is a piece of wire. The risk associated with this fix is near zero. Is it zero - no, but we spend far more money on these fuses than we would on a handful of replacement OCXO’s. Bob On Sep 3, 2014, at 5:29 AM, David McGaw wrote: > Let's try this again: > > They are HP/Agilent/Keysight PN 10811-80008. I was actually able to buy a > couple from Agilent a few years ago. They are listed as obsolete now. A > Panasonic EYP2BH115 should fit. Newark has them. > > David > > > On 9/2/14 8:05 PM, Dave Daniel wrote: >> I believe a thermal cut-out is a device which interrupts the circuit when a >> prescribed temperature is reached or exceeded (in some cases by heating >> from an increase in current through a conductor), but which re-connects the >> circuit once the temperature has dropped below the cut-out temperature >> (possibly with some hysteresis built in). A fuse, on the other hand, >> interrupts the circuit after a certain current threshold is exceeded (and, >> of course there is an increase in temperature related to the increase in >> current) but which is destroyed in the process out interrupting the circuit. >> >> DaveD >> >> On 9/2/2014 5:10 PM, Dan Rae wrote: >>> On 9/2/2014 12:23 PM, Dan Rae wrote: I'm sure this has been discussed to death before, but does anyone know of a source of thermal fuses small enough to fit in the -hp- 10811? I have found plenty of larger ones, none of which will fit and would rather not just link it out. Dan ___ >>> Thanks for all the tips and advice. >>> >>> The Chinese eBay ones (15A) I have bought before and they are physically >>> too big to fit. >>> >>> Buerklin is a German distributor and will want 28 Euros to ship to the US. >>> >>> I know I can link it out, but don't like doing that in something that is >>> powered on permanently. >>> >>> I have found some Panasonic ones that Digikey distribute in the US, but >>> frustratingly the data sheets have no dimensions given. I have ordered some >>> 1A and 2A ones to try, and will report further. >>> >>> I suspect that the originals would have been around 115C. And for >>> searching they seem to be called Thermal Cut Outs (TCO), not fuses. >>> >>> Dan >>> ___ >>> 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. >> >> ___ >> 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. > > ___ > 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. ___ 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.
Re: [time-nuts] 10811 Thermal fuse?
Let's try this again: They are HP/Agilent/Keysight PN 10811-80008. I was actually able to buy a couple from Agilent a few years ago. They are listed as obsolete now. A Panasonic EYP2BH115 should fit. Newark has them. David On 9/2/14 8:05 PM, Dave Daniel wrote: I believe a thermal cut-out is a device which interrupts the circuit when a prescribed temperature is reached or exceeded (in some cases by heating from an increase in current through a conductor), but which re-connects the circuit once the temperature has dropped below the cut-out temperature (possibly with some hysteresis built in). A fuse, on the other hand, interrupts the circuit after a certain current threshold is exceeded (and, of course there is an increase in temperature related to the increase in current) but which is destroyed in the process out interrupting the circuit. DaveD On 9/2/2014 5:10 PM, Dan Rae wrote: On 9/2/2014 12:23 PM, Dan Rae wrote: I'm sure this has been discussed to death before, but does anyone know of a source of thermal fuses small enough to fit in the -hp- 10811? I have found plenty of larger ones, none of which will fit and would rather not just link it out. Dan ___ Thanks for all the tips and advice. The Chinese eBay ones (15A) I have bought before and they are physically too big to fit. Buerklin is a German distributor and will want 28 Euros to ship to the US. I know I can link it out, but don't like doing that in something that is powered on permanently. I have found some Panasonic ones that Digikey distribute in the US, but frustratingly the data sheets have no dimensions given. I have ordered some 1A and 2A ones to try, and will report further. I suspect that the originals would have been around 115C. And for searching they seem to be called Thermal Cut Outs (TCO), not fuses. Dan ___ 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. ___ 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. ___ 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.
