Hello to the group. I have had a AN/URQ-13 or FE-15a oven oscillator for years. Its never worked correctly and in reality some early alpha build. (Funny that its labeled 15a) Looking online there is no documentation that I have been able to find over the years. However in another discussion on a AN/URQ-23 that does have a manual and schematics I realized my guesses on power could be totally wrong. Using voltages like the URQ23 the URQ13 actually behaves fairly well. I was lucky that I didn't destroy something with my original guess. That said what I find odd is the internal crystal oven runs at exactly 110 degrees. Its repeatably warms to that level with a range of supply from +/- 12-15V. Does 110 degrees F make any sense at all? Thank you Paul WB8TSL

Hi 110 F makes very little sense unless you are in a very cold climate. For military gear (or any gear for that matter) 43C on the oven just doesn’t work. 110 C would make sense in a very high temperature environment. (think of 85C upper end ….). Bob > On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: > > Hello to the group. > I have had a AN/URQ-13 or FE-15a oven oscillator for years. > Its never worked correctly and in reality some early alpha build. (Funny > that its labeled 15a) > Looking online there is no documentation that I have been able to find over > the years. > However in another discussion on a AN/URQ-23 that does have a manual and > schematics I realized my guesses on power could be totally wrong. Using > voltages like the URQ23 the URQ13 actually behaves fairly well. I was lucky > that I didn't destroy something with my original guess. > That said what I find odd is the internal crystal oven runs at exactly 110 > degrees. Its repeatably warms to that level with a range of supply from +/- > 12-15V. > Does 110 degrees F make any sense at all? > Thank you > Paul > WB8TSL > _______________________________________________ > 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.

OK I have had several responses and 110F is low as I expected. Wonder if I am being faked out? Perhaps by an inner oven and I am only reading the outside of the outer oven. The Older URQ10 and newer URQ23 do have 2 ovens. The meter switch for test is only labeled 1-9. no other clues to the function. I noticed 2 positions change with warm up. Sort of supports the 2 oven theory. Really do not want to take what might be the outer oven off to put the probe in. Thanks everyone. Paul WB8TSL On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > Hi > > 110 F makes very little sense unless you are in a very cold climate. > For military gear (or any gear for that matter) 43C on the oven just > doesn’t work. > > 110 C would make sense in a very high temperature environment. > (think of 85C upper end ….). > > Bob > > > On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: > > > > Hello to the group. > > I have had a AN/URQ-13 or FE-15a oven oscillator for years. > > Its never worked correctly and in reality some early alpha build. (Funny > > that its labeled 15a) > > Looking online there is no documentation that I have been able to find > over > > the years. > > However in another discussion on a AN/URQ-23 that does have a manual and > > schematics I realized my guesses on power could be totally wrong. Using > > voltages like the URQ23 the URQ13 actually behaves fairly well. I was > lucky > > that I didn't destroy something with my original guess. > > That said what I find odd is the internal crystal oven runs at exactly > 110 > > degrees. Its repeatably warms to that level with a range of supply from > +/- > > 12-15V. > > Does 110 degrees F make any sense at all? > > Thank you > > Paul > > WB8TSL > > _______________________________________________ > > 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 Even for an outer oven, anything below 60C / 140F would be low enough to run into significant problems. On a mil device, an upper end temperature on the equipment likely would be over 70C. The outer oven would need to be 5 to 10C above that. Bob > On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > > OK I have had several responses and 110F is low as I expected. > Wonder if I am being faked out? Perhaps by an inner oven and I am only > reading the outside of the outer oven. The Older URQ10 and newer URQ23 do > have 2 ovens. The meter switch for test is only labeled 1-9. no other clues > to the function. I noticed 2 positions change with warm up. Sort of > supports the 2 oven theory. > Really do not want to take what might be the outer oven off to put the > probe in. > Thanks everyone. > Paul > WB8TSL > > On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > >> Hi >> >> 110 F makes very little sense unless you are in a very cold climate. >> For military gear (or any gear for that matter) 43C on the oven just >> doesn’t work. >> >> 110 C would make sense in a very high temperature environment. >> (think of 85C upper end ….). >> >> Bob >> >>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: >>> >>> Hello to the group. >>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >>> Its never worked correctly and in reality some early alpha build. (Funny >>> that its labeled 15a) >>> Looking online there is no documentation that I have been able to find >> over >>> the years. >>> However in another discussion on a AN/URQ-23 that does have a manual and >>> schematics I realized my guesses on power could be totally wrong. Using >>> voltages like the URQ23 the URQ13 actually behaves fairly well. I was >> lucky >>> that I didn't destroy something with my original guess. >>> That said what I find odd is the internal crystal oven runs at exactly >> 110 >>> degrees. Its repeatably warms to that level with a range of supply from >> +/- >>> 12-15V. >>> Does 110 degrees F make any sense at all? >>> Thank you >>> Paul >>> WB8TSL >>> _______________________________________________ >>> 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.

50C is what I have sort of seen over the years. Just wondered could there have been a lower temp version. That made no sense. But then this beast has never made a lot of sense. The $20 mystery from Frequency Electronics. Thanks Bob Paul WB8TSL On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: > Hi > > Even for an outer oven, anything below 60C / 140F would be low enough to > run into significant problems. On a mil device, an upper end temperature > on > the equipment likely would be over 70C. The outer oven would need to be > 5 to 10C above that. > > Bob > > > On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > > > > OK I have had several responses and 110F is low as I expected. > > Wonder if I am being faked out? Perhaps by an inner oven and I am only > > reading the outside of the outer oven. The Older URQ10 and newer URQ23 do > > have 2 ovens. The meter switch for test is only labeled 1-9. no other > clues > > to the function. I noticed 2 positions change with warm up. Sort of > > supports the 2 oven theory. > > Really do not want to take what might be the outer oven off to put the > > probe in. > > Thanks everyone. > > Paul > > WB8TSL > > > > On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > > > >> Hi > >> > >> 110 F makes very little sense unless you are in a very cold climate. > >> For military gear (or any gear for that matter) 43C on the oven just > >> doesn’t work. > >> > >> 110 C would make sense in a very high temperature environment. > >> (think of 85C upper end ….). > >> > >> Bob > >> > >>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: > >>> > >>> Hello to the group. > >>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. > >>> Its never worked correctly and in reality some early alpha build. > (Funny > >>> that its labeled 15a) > >>> Looking online there is no documentation that I have been able to find > >> over > >>> the years. > >>> However in another discussion on a AN/URQ-23 that does have a manual > and > >>> schematics I realized my guesses on power could be totally wrong. Using > >>> voltages like the URQ23 the URQ13 actually behaves fairly well. I was > >> lucky > >>> that I didn't destroy something with my original guess. > >>> That said what I find odd is the internal crystal oven runs at exactly > >> 110 > >>> degrees. Its repeatably warms to that level with a range of supply from > >> +/- > >>> 12-15V. > >>> Does 110 degrees F make any sense at all? > >>> Thank you > >>> Paul > >>> WB8TSL > >>> _______________________________________________ > >>> 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. > > > _______________________________________________ > 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. >

Shouldn't the outer oven be cooler than the inner oven except during warmup? I would think the inner electronics would be generating heat. Paul Alfille K1PHA On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: > 50C is what I have sort of seen over the years. Just wondered could there > have been a lower temp version. That made no sense. But then this beast has > never made a lot of sense. The $20 mystery from Frequency Electronics. > Thanks Bob > Paul > WB8TSL > > On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: > > > Hi > > > > Even for an outer oven, anything below 60C / 140F would be low enough to > > run into significant problems. On a mil device, an upper end temperature > > on > > the equipment likely would be over 70C. The outer oven would need to be > > 5 to 10C above that. > > > > Bob > > > > > On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > > > > > > OK I have had several responses and 110F is low as I expected. > > > Wonder if I am being faked out? Perhaps by an inner oven and I am only > > > reading the outside of the outer oven. The Older URQ10 and newer URQ23 > do > > > have 2 ovens. The meter switch for test is only labeled 1-9. no other > > clues > > > to the function. I noticed 2 positions change with warm up. Sort of > > > supports the 2 oven theory. > > > Really do not want to take what might be the outer oven off to put the > > > probe in. > > > Thanks everyone. > > > Paul > > > WB8TSL > > > > > > On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > > > > > >> Hi > > >> > > >> 110 F makes very little sense unless you are in a very cold climate. > > >> For military gear (or any gear for that matter) 43C on the oven just > > >> doesn’t work. > > >> > > >> 110 C would make sense in a very high temperature environment. > > >> (think of 85C upper end ….). > > >> > > >> Bob > > >> > > >>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: > > >>> > > >>> Hello to the group. > > >>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. > > >>> Its never worked correctly and in reality some early alpha build. > > (Funny > > >>> that its labeled 15a) > > >>> Looking online there is no documentation that I have been able to > find > > >> over > > >>> the years. > > >>> However in another discussion on a AN/URQ-23 that does have a manual > > and > > >>> schematics I realized my guesses on power could be totally wrong. > Using > > >>> voltages like the URQ23 the URQ13 actually behaves fairly well. I was > > >> lucky > > >>> that I didn't destroy something with my original guess. > > >>> That said what I find odd is the internal crystal oven runs at > exactly > > >> 110 > > >>> degrees. Its repeatably warms to that level with a range of supply > from > > >> +/- > > >>> 12-15V. > > >>> Does 110 degrees F make any sense at all? > > >>> Thank you > > >>> Paul > > >>> WB8TSL > > >>> _______________________________________________ > > >>> 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. > > > > > > _______________________________________________ > > 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. >

Paul This is Paul to confuse the thread. I always thought the outer was cooler also. Its becoming clear many things I have learned over the years might be a bit off. I was thinking of looking at several other references that do have documentation urq10 and 23. See what the maintenance documents say. The good thing about military stuff is the manuals tend to have some good details. Will see. Paul WB8TSL On Thu, Feb 11, 2021 at 10:39 PM Paul Alfille <paul.alfille@gmail.com> wrote: > Shouldn't the outer oven be cooler than the inner oven except during > warmup? I would think the inner electronics would be generating heat. > > Paul Alfille K1PHA > > On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: > > > 50C is what I have sort of seen over the years. Just wondered could there > > have been a lower temp version. That made no sense. But then this beast > has > > never made a lot of sense. The $20 mystery from Frequency Electronics. > > Thanks Bob > > Paul > > WB8TSL > > > > On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: > > > > > Hi > > > > > > Even for an outer oven, anything below 60C / 140F would be low enough > to > > > run into significant problems. On a mil device, an upper end > temperature > > > on > > > the equipment likely would be over 70C. The outer oven would need to be > > > 5 to 10C above that. > > > > > > Bob > > > > > > > On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > > > > > > > > OK I have had several responses and 110F is low as I expected. > > > > Wonder if I am being faked out? Perhaps by an inner oven and I am > only > > > > reading the outside of the outer oven. The Older URQ10 and newer > URQ23 > > do > > > > have 2 ovens. The meter switch for test is only labeled 1-9. no other > > > clues > > > > to the function. I noticed 2 positions change with warm up. Sort of > > > > supports the 2 oven theory. > > > > Really do not want to take what might be the outer oven off to put > the > > > > probe in. > > > > Thanks everyone. > > > > Paul > > > > WB8TSL > > > > > > > > On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > > > > > > > >> Hi > > > >> > > > >> 110 F makes very little sense unless you are in a very cold climate. > > > >> For military gear (or any gear for that matter) 43C on the oven just > > > >> doesn’t work. > > > >> > > > >> 110 C would make sense in a very high temperature environment. > > > >> (think of 85C upper end ….). > > > >> > > > >> Bob > > > >> > > > >>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> > wrote: > > > >>> > > > >>> Hello to the group. > > > >>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. > > > >>> Its never worked correctly and in reality some early alpha build. > > > (Funny > > > >>> that its labeled 15a) > > > >>> Looking online there is no documentation that I have been able to > > find > > > >> over > > > >>> the years. > > > >>> However in another discussion on a AN/URQ-23 that does have a > manual > > > and > > > >>> schematics I realized my guesses on power could be totally wrong. > > Using > > > >>> voltages like the URQ23 the URQ13 actually behaves fairly well. I > was > > > >> lucky > > > >>> that I didn't destroy something with my original guess. > > > >>> That said what I find odd is the internal crystal oven runs at > > exactly > > > >> 110 > > > >>> degrees. Its repeatably warms to that level with a range of supply > > from > > > >> +/- > > > >>> 12-15V. > > > >>> Does 110 degrees F make any sense at all? > > > >>> Thank you > > > >>> Paul > > > >>> WB8TSL > > > >>> _______________________________________________ > > > >>> 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. > > > > > > > > > _______________________________________________ > > > 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 Indeed the outer oven (as a minimum) needs to be 5 to 10 C above the maximum ambient. If it’s not it goes out of regulation (runs away) and you loose any benefit from it. ( = it now works against you ). The inner oven as a minimum needs to be 5 to 10 C above the outer oven. Again if it is lower, you can / will get into the same runaway issue. Those offsets are dependent on the way things are insulated. If you are using a dewar flask, 5C is probably not going to work for you. Your inner oven *also* is impacted by the turn temperature on the crystal being used. This *might* have a 20C range. That would put the maximum inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. Needless to say, if the max ambient is 85C, this will get the inner oven components up pretty hot. That’s not a real good idea. Derating the heater is pretty easy, derating *everything* in there is much more complex. You do not often see 85C upper end double ovens …. One *could* also ask: “is all this worth it?”. List members *have* written papers addressing that point :) Bob > On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> wrote: > > Shouldn't the outer oven be cooler than the inner oven except during > warmup? I would think the inner electronics would be generating heat. > > Paul Alfille K1PHA > > On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: > >> 50C is what I have sort of seen over the years. Just wondered could there >> have been a lower temp version. That made no sense. But then this beast has >> never made a lot of sense. The $20 mystery from Frequency Electronics. >> Thanks Bob >> Paul >> WB8TSL >> >> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >> >>> Hi >>> >>> Even for an outer oven, anything below 60C / 140F would be low enough to >>> run into significant problems. On a mil device, an upper end temperature >>> on >>> the equipment likely would be over 70C. The outer oven would need to be >>> 5 to 10C above that. >>> >>> Bob >>> >>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: >>>> >>>> OK I have had several responses and 110F is low as I expected. >>>> Wonder if I am being faked out? Perhaps by an inner oven and I am only >>>> reading the outside of the outer oven. The Older URQ10 and newer URQ23 >> do >>>> have 2 ovens. The meter switch for test is only labeled 1-9. no other >>> clues >>>> to the function. I noticed 2 positions change with warm up. Sort of >>>> supports the 2 oven theory. >>>> Really do not want to take what might be the outer oven off to put the >>>> probe in. >>>> Thanks everyone. >>>> Paul >>>> WB8TSL >>>> >>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>> >>>>> Hi >>>>> >>>>> 110 F makes very little sense unless you are in a very cold climate. >>>>> For military gear (or any gear for that matter) 43C on the oven just >>>>> doesn’t work. >>>>> >>>>> 110 C would make sense in a very high temperature environment. >>>>> (think of 85C upper end ….). >>>>> >>>>> Bob >>>>> >>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: >>>>>> >>>>>> Hello to the group. >>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >>>>>> Its never worked correctly and in reality some early alpha build. >>> (Funny >>>>>> that its labeled 15a) >>>>>> Looking online there is no documentation that I have been able to >> find >>>>> over >>>>>> the years. >>>>>> However in another discussion on a AN/URQ-23 that does have a manual >>> and >>>>>> schematics I realized my guesses on power could be totally wrong. >> Using >>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I was >>>>> lucky >>>>>> that I didn't destroy something with my original guess. >>>>>> That said what I find odd is the internal crystal oven runs at >> exactly >>>>> 110 >>>>>> degrees. Its repeatably warms to that level with a range of supply >> from >>>>> +/- >>>>>> 12-15V. >>>>>> Does 110 degrees F make any sense at all? >>>>>> Thank you >>>>>> Paul >>>>>> WB8TSL >>>>>> _______________________________________________ >>>>>> 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. >>> >>> >>> _______________________________________________ >>> 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.

Bad news for me. None of the military manuals states the temperatures of the inner and outer ovens. Pretty sure various HP manuals never did either. Regards Paul. On Fri, Feb 12, 2021 at 9:22 AM paul swed <paulswedb@gmail.com> wrote: > Paul > This is Paul to confuse the thread. I always thought the outer was cooler > also. Its becoming clear many things I have learned over the years might be > a bit off. I was thinking of looking at several other references that do > have documentation urq10 and 23. See what the maintenance documents say. > The good thing about military stuff is the manuals tend to have some good > details. Will see. > Paul > WB8TSL > > On Thu, Feb 11, 2021 at 10:39 PM Paul Alfille <paul.alfille@gmail.com> > wrote: > >> Shouldn't the outer oven be cooler than the inner oven except during >> warmup? I would think the inner electronics would be generating heat. >> >> Paul Alfille K1PHA >> >> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: >> >> > 50C is what I have sort of seen over the years. Just wondered could >> there >> > have been a lower temp version. That made no sense. But then this beast >> has >> > never made a lot of sense. The $20 mystery from Frequency Electronics. >> > Thanks Bob >> > Paul >> > WB8TSL >> > >> > On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >> > >> > > Hi >> > > >> > > Even for an outer oven, anything below 60C / 140F would be low enough >> to >> > > run into significant problems. On a mil device, an upper end >> temperature >> > > on >> > > the equipment likely would be over 70C. The outer oven would need to >> be >> > > 5 to 10C above that. >> > > >> > > Bob >> > > >> > > > On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: >> > > > >> > > > OK I have had several responses and 110F is low as I expected. >> > > > Wonder if I am being faked out? Perhaps by an inner oven and I am >> only >> > > > reading the outside of the outer oven. The Older URQ10 and newer >> URQ23 >> > do >> > > > have 2 ovens. The meter switch for test is only labeled 1-9. no >> other >> > > clues >> > > > to the function. I noticed 2 positions change with warm up. Sort of >> > > > supports the 2 oven theory. >> > > > Really do not want to take what might be the outer oven off to put >> the >> > > > probe in. >> > > > Thanks everyone. >> > > > Paul >> > > > WB8TSL >> > > > >> > > > On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >> > > > >> > > >> Hi >> > > >> >> > > >> 110 F makes very little sense unless you are in a very cold >> climate. >> > > >> For military gear (or any gear for that matter) 43C on the oven >> just >> > > >> doesn’t work. >> > > >> >> > > >> 110 C would make sense in a very high temperature environment. >> > > >> (think of 85C upper end ….). >> > > >> >> > > >> Bob >> > > >> >> > > >>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> >> wrote: >> > > >>> >> > > >>> Hello to the group. >> > > >>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >> > > >>> Its never worked correctly and in reality some early alpha build. >> > > (Funny >> > > >>> that its labeled 15a) >> > > >>> Looking online there is no documentation that I have been able to >> > find >> > > >> over >> > > >>> the years. >> > > >>> However in another discussion on a AN/URQ-23 that does have a >> manual >> > > and >> > > >>> schematics I realized my guesses on power could be totally wrong. >> > Using >> > > >>> voltages like the URQ23 the URQ13 actually behaves fairly well. I >> was >> > > >> lucky >> > > >>> that I didn't destroy something with my original guess. >> > > >>> That said what I find odd is the internal crystal oven runs at >> > exactly >> > > >> 110 >> > > >>> degrees. Its repeatably warms to that level with a range of supply >> > from >> > > >> +/- >> > > >>> 12-15V. >> > > >>> Does 110 degrees F make any sense at all? >> > > >>> Thank you >> > > >>> Paul >> > > >>> WB8TSL >> > > >>> _______________________________________________ >> > > >>> 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. >> > > >> > > >> > > _______________________________________________ >> > > 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. >> >

Bob OK there is the math. and that all starts to line up. So most likely for other URQ units there will be an ambient max in the spec's. At least on the URQ10 in real life even in the hot tropics the radio room was shirt sleeve temps. But the question asked was 110 F correct as measured on the outside of the outer oven against the dewar flask correct. It isn't. The darn thing is reasonably stable though. Since the front panel test switch is not labeled I speculate that the position for the outer oven is in the normal range. The next switch position most likely is inner and is not in the correct position. It slowly moves to the high side. No real details on anything and a total guess. Really appreciate the thoughts. Regards Paul WB8TSL On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: > Hi > > Indeed the outer oven (as a minimum) needs to be 5 to 10 C above > the maximum ambient. If it’s not it goes out of regulation (runs away) > and you loose any benefit from it. ( = it now works against you ). > > The inner oven as a minimum needs to be 5 to 10 C above the outer > oven. Again if it is lower, you can / will get into the same runaway > issue. > > Those offsets are dependent on the way things are insulated. If you are > using a dewar flask, 5C is probably not going to work for you. > > Your inner oven *also* is impacted by the turn temperature on the crystal > being used. This *might* have a 20C range. That would put the maximum > inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. > > Needless to say, if the max ambient is 85C, this will get the inner oven > components up pretty hot. That’s not a real good idea. Derating the heater > is pretty easy, derating *everything* in there is much more complex. You > do not often see 85C upper end double ovens …. > > One *could* also ask: “is all this worth it?”. List members *have* written > papers addressing that point :) > > Bob > > > On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> > wrote: > > > > Shouldn't the outer oven be cooler than the inner oven except during > > warmup? I would think the inner electronics would be generating heat. > > > > Paul Alfille K1PHA > > > > On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: > > > >> 50C is what I have sort of seen over the years. Just wondered could > there > >> have been a lower temp version. That made no sense. But then this beast > has > >> never made a lot of sense. The $20 mystery from Frequency Electronics. > >> Thanks Bob > >> Paul > >> WB8TSL > >> > >> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: > >> > >>> Hi > >>> > >>> Even for an outer oven, anything below 60C / 140F would be low enough > to > >>> run into significant problems. On a mil device, an upper end > temperature > >>> on > >>> the equipment likely would be over 70C. The outer oven would need to be > >>> 5 to 10C above that. > >>> > >>> Bob > >>> > >>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > >>>> > >>>> OK I have had several responses and 110F is low as I expected. > >>>> Wonder if I am being faked out? Perhaps by an inner oven and I am only > >>>> reading the outside of the outer oven. The Older URQ10 and newer URQ23 > >> do > >>>> have 2 ovens. The meter switch for test is only labeled 1-9. no other > >>> clues > >>>> to the function. I noticed 2 positions change with warm up. Sort of > >>>> supports the 2 oven theory. > >>>> Really do not want to take what might be the outer oven off to put the > >>>> probe in. > >>>> Thanks everyone. > >>>> Paul > >>>> WB8TSL > >>>> > >>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > >>>> > >>>>> Hi > >>>>> > >>>>> 110 F makes very little sense unless you are in a very cold climate. > >>>>> For military gear (or any gear for that matter) 43C on the oven just > >>>>> doesn’t work. > >>>>> > >>>>> 110 C would make sense in a very high temperature environment. > >>>>> (think of 85C upper end ….). > >>>>> > >>>>> Bob > >>>>> > >>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: > >>>>>> > >>>>>> Hello to the group. > >>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. > >>>>>> Its never worked correctly and in reality some early alpha build. > >>> (Funny > >>>>>> that its labeled 15a) > >>>>>> Looking online there is no documentation that I have been able to > >> find > >>>>> over > >>>>>> the years. > >>>>>> However in another discussion on a AN/URQ-23 that does have a manual > >>> and > >>>>>> schematics I realized my guesses on power could be totally wrong. > >> Using > >>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I > was > >>>>> lucky > >>>>>> that I didn't destroy something with my original guess. > >>>>>> That said what I find odd is the internal crystal oven runs at > >> exactly > >>>>> 110 > >>>>>> degrees. Its repeatably warms to that level with a range of supply > >> from > >>>>> +/- > >>>>>> 12-15V. > >>>>>> Does 110 degrees F make any sense at all? > >>>>>> Thank you > >>>>>> Paul > >>>>>> WB8TSL > >>>>>> _______________________________________________ > >>>>>> 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. > >>> > >>> > >>> _______________________________________________ > >>> 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. > > > _______________________________________________ > 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 it’s 105F “outdoors” that’s 40C. Military gear back in the days of the URQ10 did not live in air conditioned enclosures. It did get deployed to places with temperatures at or above that level. If it’s 40C outdoors, by the time you get to a pile of electronics gear *indoors*, a >10C rise is pretty likely. That drives a very common 50C “upper end” temperature on ground gear in relatively benign installations. This does not just apply to military gear. If you look through test equipment catalogs, a lot of test gear also has the same sort of 50 to 60C upper end spec. The 5065A has a spec of 0 to 50C. The 5061A has the same spec. Both targeted pretty “normal” environments …. ( = they never get below freezing …) and date to the “era” of the URQ10. In this era of HVAC everywhere, the 5071A has a temp range of 0 to 55C. If anything, this would suggest that things still can get pretty hot. Bob > On Feb 12, 2021, at 10:29 AM, paul swed <paulswedb@gmail.com> wrote: > > Bob > OK there is the math. and that all starts to line up. > So most likely for other URQ units there will be an ambient max in the > spec's. At least on the URQ10 in real life even in the hot tropics the > radio room was shirt sleeve temps. > But the question asked was 110 F correct as measured on the outside of the > outer oven against the dewar flask correct. It isn't. The darn thing is > reasonably stable though. > Since the front panel test switch is not labeled I speculate that the > position for the outer oven is in the normal range. The next switch > position most likely is inner and is not in the correct position. It slowly > moves to the high side. > No real details on anything and a total guess. > Really appreciate the thoughts. > Regards > Paul > WB8TSL > > On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: > >> Hi >> >> Indeed the outer oven (as a minimum) needs to be 5 to 10 C above >> the maximum ambient. If it’s not it goes out of regulation (runs away) >> and you loose any benefit from it. ( = it now works against you ). >> >> The inner oven as a minimum needs to be 5 to 10 C above the outer >> oven. Again if it is lower, you can / will get into the same runaway >> issue. >> >> Those offsets are dependent on the way things are insulated. If you are >> using a dewar flask, 5C is probably not going to work for you. >> >> Your inner oven *also* is impacted by the turn temperature on the crystal >> being used. This *might* have a 20C range. That would put the maximum >> inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. >> >> Needless to say, if the max ambient is 85C, this will get the inner oven >> components up pretty hot. That’s not a real good idea. Derating the heater >> is pretty easy, derating *everything* in there is much more complex. You >> do not often see 85C upper end double ovens …. >> >> One *could* also ask: “is all this worth it?”. List members *have* written >> papers addressing that point :) >> >> Bob >> >>> On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> >> wrote: >>> >>> Shouldn't the outer oven be cooler than the inner oven except during >>> warmup? I would think the inner electronics would be generating heat. >>> >>> Paul Alfille K1PHA >>> >>> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: >>> >>>> 50C is what I have sort of seen over the years. Just wondered could >> there >>>> have been a lower temp version. That made no sense. But then this beast >> has >>>> never made a lot of sense. The $20 mystery from Frequency Electronics. >>>> Thanks Bob >>>> Paul >>>> WB8TSL >>>> >>>> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>> >>>>> Hi >>>>> >>>>> Even for an outer oven, anything below 60C / 140F would be low enough >> to >>>>> run into significant problems. On a mil device, an upper end >> temperature >>>>> on >>>>> the equipment likely would be over 70C. The outer oven would need to be >>>>> 5 to 10C above that. >>>>> >>>>> Bob >>>>> >>>>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: >>>>>> >>>>>> OK I have had several responses and 110F is low as I expected. >>>>>> Wonder if I am being faked out? Perhaps by an inner oven and I am only >>>>>> reading the outside of the outer oven. The Older URQ10 and newer URQ23 >>>> do >>>>>> have 2 ovens. The meter switch for test is only labeled 1-9. no other >>>>> clues >>>>>> to the function. I noticed 2 positions change with warm up. Sort of >>>>>> supports the 2 oven theory. >>>>>> Really do not want to take what might be the outer oven off to put the >>>>>> probe in. >>>>>> Thanks everyone. >>>>>> Paul >>>>>> WB8TSL >>>>>> >>>>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>>>> >>>>>>> Hi >>>>>>> >>>>>>> 110 F makes very little sense unless you are in a very cold climate. >>>>>>> For military gear (or any gear for that matter) 43C on the oven just >>>>>>> doesn’t work. >>>>>>> >>>>>>> 110 C would make sense in a very high temperature environment. >>>>>>> (think of 85C upper end ….). >>>>>>> >>>>>>> Bob >>>>>>> >>>>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> wrote: >>>>>>>> >>>>>>>> Hello to the group. >>>>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >>>>>>>> Its never worked correctly and in reality some early alpha build. >>>>> (Funny >>>>>>>> that its labeled 15a) >>>>>>>> Looking online there is no documentation that I have been able to >>>> find >>>>>>> over >>>>>>>> the years. >>>>>>>> However in another discussion on a AN/URQ-23 that does have a manual >>>>> and >>>>>>>> schematics I realized my guesses on power could be totally wrong. >>>> Using >>>>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I >> was >>>>>>> lucky >>>>>>>> that I didn't destroy something with my original guess. >>>>>>>> That said what I find odd is the internal crystal oven runs at >>>> exactly >>>>>>> 110 >>>>>>>> degrees. Its repeatably warms to that level with a range of supply >>>> from >>>>>>> +/- >>>>>>>> 12-15V. >>>>>>>> Does 110 degrees F make any sense at all? >>>>>>>> Thank you >>>>>>>> Paul >>>>>>>> WB8TSL >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >> >> >> _______________________________________________ >> 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.

Yes Bob they could get hot. But the radio rooms I have been in circa 1970s were all air conditioned from destroyers to aircraft carriers. Shirt sleeve. The best place to actually be when we were down by the equator was the radio room, ET shop, CIC and radar and just maybe the Captain's stateroom. But if you were actually there you might still be sweating. Chuckle. This conversation has given me some good insights. Later today I will disable the outer oven. Just curious to see what possible temps might show up. Is the inner oven simply reading outer oven leakage. Is there a lead I can measure the current of the inner oven.... Thanks On Fri, Feb 12, 2021 at 11:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: > Hi > > If it’s 105F “outdoors” that’s 40C. Military gear back in the days of the > URQ10 > did not live in air conditioned enclosures. It did get deployed to places > with > temperatures at or above that level. > > If it’s 40C outdoors, by the time you get to a pile of electronics gear > *indoors*, > a >10C rise is pretty likely. That drives a very common 50C “upper end” > temperature > on ground gear in relatively benign installations. > > This does not just apply to military gear. If you look through test > equipment > catalogs, a lot of test gear also has the same sort of 50 to 60C upper end > spec. > The 5065A has a spec of 0 to 50C. The 5061A has the same spec. Both > targeted > pretty “normal” environments …. ( = they never get below freezing …) and > date > to the “era” of the URQ10. > > In this era of HVAC everywhere, the 5071A has a temp range of 0 to 55C. If > anything, this would suggest that things still can get pretty hot. > > Bob > > > On Feb 12, 2021, at 10:29 AM, paul swed <paulswedb@gmail.com> wrote: > > > > Bob > > OK there is the math. and that all starts to line up. > > So most likely for other URQ units there will be an ambient max in the > > spec's. At least on the URQ10 in real life even in the hot tropics the > > radio room was shirt sleeve temps. > > But the question asked was 110 F correct as measured on the outside of > the > > outer oven against the dewar flask correct. It isn't. The darn thing is > > reasonably stable though. > > Since the front panel test switch is not labeled I speculate that the > > position for the outer oven is in the normal range. The next switch > > position most likely is inner and is not in the correct position. It > slowly > > moves to the high side. > > No real details on anything and a total guess. > > Really appreciate the thoughts. > > Regards > > Paul > > WB8TSL > > > > On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: > > > >> Hi > >> > >> Indeed the outer oven (as a minimum) needs to be 5 to 10 C above > >> the maximum ambient. If it’s not it goes out of regulation (runs away) > >> and you loose any benefit from it. ( = it now works against you ). > >> > >> The inner oven as a minimum needs to be 5 to 10 C above the outer > >> oven. Again if it is lower, you can / will get into the same runaway > >> issue. > >> > >> Those offsets are dependent on the way things are insulated. If you are > >> using a dewar flask, 5C is probably not going to work for you. > >> > >> Your inner oven *also* is impacted by the turn temperature on the > crystal > >> being used. This *might* have a 20C range. That would put the maximum > >> inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. > >> > >> Needless to say, if the max ambient is 85C, this will get the inner oven > >> components up pretty hot. That’s not a real good idea. Derating the > heater > >> is pretty easy, derating *everything* in there is much more complex. You > >> do not often see 85C upper end double ovens …. > >> > >> One *could* also ask: “is all this worth it?”. List members *have* > written > >> papers addressing that point :) > >> > >> Bob > >> > >>> On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> > >> wrote: > >>> > >>> Shouldn't the outer oven be cooler than the inner oven except during > >>> warmup? I would think the inner electronics would be generating heat. > >>> > >>> Paul Alfille K1PHA > >>> > >>> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> wrote: > >>> > >>>> 50C is what I have sort of seen over the years. Just wondered could > >> there > >>>> have been a lower temp version. That made no sense. But then this > beast > >> has > >>>> never made a lot of sense. The $20 mystery from Frequency Electronics. > >>>> Thanks Bob > >>>> Paul > >>>> WB8TSL > >>>> > >>>> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: > >>>> > >>>>> Hi > >>>>> > >>>>> Even for an outer oven, anything below 60C / 140F would be low enough > >> to > >>>>> run into significant problems. On a mil device, an upper end > >> temperature > >>>>> on > >>>>> the equipment likely would be over 70C. The outer oven would need to > be > >>>>> 5 to 10C above that. > >>>>> > >>>>> Bob > >>>>> > >>>>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> wrote: > >>>>>> > >>>>>> OK I have had several responses and 110F is low as I expected. > >>>>>> Wonder if I am being faked out? Perhaps by an inner oven and I am > only > >>>>>> reading the outside of the outer oven. The Older URQ10 and newer > URQ23 > >>>> do > >>>>>> have 2 ovens. The meter switch for test is only labeled 1-9. no > other > >>>>> clues > >>>>>> to the function. I noticed 2 positions change with warm up. Sort of > >>>>>> supports the 2 oven theory. > >>>>>> Really do not want to take what might be the outer oven off to put > the > >>>>>> probe in. > >>>>>> Thanks everyone. > >>>>>> Paul > >>>>>> WB8TSL > >>>>>> > >>>>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: > >>>>>> > >>>>>>> Hi > >>>>>>> > >>>>>>> 110 F makes very little sense unless you are in a very cold > climate. > >>>>>>> For military gear (or any gear for that matter) 43C on the oven > just > >>>>>>> doesn’t work. > >>>>>>> > >>>>>>> 110 C would make sense in a very high temperature environment. > >>>>>>> (think of 85C upper end ….). > >>>>>>> > >>>>>>> Bob > >>>>>>> > >>>>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> > wrote: > >>>>>>>> > >>>>>>>> Hello to the group. > >>>>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. > >>>>>>>> Its never worked correctly and in reality some early alpha build. > >>>>> (Funny > >>>>>>>> that its labeled 15a) > >>>>>>>> Looking online there is no documentation that I have been able to > >>>> find > >>>>>>> over > >>>>>>>> the years. > >>>>>>>> However in another discussion on a AN/URQ-23 that does have a > manual > >>>>> and > >>>>>>>> schematics I realized my guesses on power could be totally wrong. > >>>> Using > >>>>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I > >> was > >>>>>>> lucky > >>>>>>>> that I didn't destroy something with my original guess. > >>>>>>>> That said what I find odd is the internal crystal oven runs at > >>>> exactly > >>>>>>> 110 > >>>>>>>> degrees. Its repeatably warms to that level with a range of supply > >>>> from > >>>>>>> +/- > >>>>>>>> 12-15V. > >>>>>>>> Does 110 degrees F make any sense at all? > >>>>>>>> Thank you > >>>>>>>> Paul > >>>>>>>> WB8TSL > >>>>>>>> _______________________________________________ > >>>>>>>> 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. > >>>>> > >>>>> > >>>>> _______________________________________________ > >>>>> 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. > >> > >> > >> _______________________________________________ > >> 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. >

Well there is no doubt someone has been deep into this unit. Hint missing screws internally. But appears both heater windings are ok. So inner and outer oven has a new meaning. I typically understood this to be one oven in another oven. Think the HP CS units of old. The same in other places HP3801. But in the URQ13 it means there is a long tube. The Dewar flask. The inner is deep into the flask and the outer is close to the opening. Two completely separate heaters. Under the outer heater I will guess is the actual oscillator for the 5 MHz. Further out from the outer heater are the offset variable caps thermistor for the outer oven a pot and IC. Several screws hold this outer heater on and considering the risk of taking out the remainders to look and draw a schematic. Regards Paul On Fri, Feb 12, 2021 at 11:28 AM paul swed <paulswedb@gmail.com> wrote: > Yes Bob they could get hot. But the radio rooms I have been in circa 1970s > were all air conditioned from destroyers to aircraft carriers. Shirt > sleeve. The best place to actually be when we were down by the equator was > the radio room, ET shop, CIC and radar and just maybe the Captain's > stateroom. But if you were actually there you might still be sweating. > Chuckle. > This conversation has given me some good insights. Later today I will > disable the outer oven. Just curious to see what possible temps might show > up. Is the inner oven simply reading outer oven leakage. Is there a lead I > can measure the current of the inner oven.... > Thanks > > On Fri, Feb 12, 2021 at 11:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: > >> Hi >> >> If it’s 105F “outdoors” that’s 40C. Military gear back in the days of the >> URQ10 >> did not live in air conditioned enclosures. It did get deployed to places >> with >> temperatures at or above that level. >> >> If it’s 40C outdoors, by the time you get to a pile of electronics gear >> *indoors*, >> a >10C rise is pretty likely. That drives a very common 50C “upper end” >> temperature >> on ground gear in relatively benign installations. >> >> This does not just apply to military gear. If you look through test >> equipment >> catalogs, a lot of test gear also has the same sort of 50 to 60C upper >> end spec. >> The 5065A has a spec of 0 to 50C. The 5061A has the same spec. Both >> targeted >> pretty “normal” environments …. ( = they never get below freezing …) and >> date >> to the “era” of the URQ10. >> >> In this era of HVAC everywhere, the 5071A has a temp range of 0 to 55C. >> If >> anything, this would suggest that things still can get pretty hot. >> >> Bob >> >> > On Feb 12, 2021, at 10:29 AM, paul swed <paulswedb@gmail.com> wrote: >> > >> > Bob >> > OK there is the math. and that all starts to line up. >> > So most likely for other URQ units there will be an ambient max in the >> > spec's. At least on the URQ10 in real life even in the hot tropics the >> > radio room was shirt sleeve temps. >> > But the question asked was 110 F correct as measured on the outside of >> the >> > outer oven against the dewar flask correct. It isn't. The darn thing is >> > reasonably stable though. >> > Since the front panel test switch is not labeled I speculate that the >> > position for the outer oven is in the normal range. The next switch >> > position most likely is inner and is not in the correct position. It >> slowly >> > moves to the high side. >> > No real details on anything and a total guess. >> > Really appreciate the thoughts. >> > Regards >> > Paul >> > WB8TSL >> > >> > On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: >> > >> >> Hi >> >> >> >> Indeed the outer oven (as a minimum) needs to be 5 to 10 C above >> >> the maximum ambient. If it’s not it goes out of regulation (runs away) >> >> and you loose any benefit from it. ( = it now works against you ). >> >> >> >> The inner oven as a minimum needs to be 5 to 10 C above the outer >> >> oven. Again if it is lower, you can / will get into the same runaway >> >> issue. >> >> >> >> Those offsets are dependent on the way things are insulated. If you are >> >> using a dewar flask, 5C is probably not going to work for you. >> >> >> >> Your inner oven *also* is impacted by the turn temperature on the >> crystal >> >> being used. This *might* have a 20C range. That would put the maximum >> >> inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. >> >> >> >> Needless to say, if the max ambient is 85C, this will get the inner >> oven >> >> components up pretty hot. That’s not a real good idea. Derating the >> heater >> >> is pretty easy, derating *everything* in there is much more complex. >> You >> >> do not often see 85C upper end double ovens …. >> >> >> >> One *could* also ask: “is all this worth it?”. List members *have* >> written >> >> papers addressing that point :) >> >> >> >> Bob >> >> >> >>> On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> >> >> wrote: >> >>> >> >>> Shouldn't the outer oven be cooler than the inner oven except during >> >>> warmup? I would think the inner electronics would be generating heat. >> >>> >> >>> Paul Alfille K1PHA >> >>> >> >>> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> >> wrote: >> >>> >> >>>> 50C is what I have sort of seen over the years. Just wondered could >> >> there >> >>>> have been a lower temp version. That made no sense. But then this >> beast >> >> has >> >>>> never made a lot of sense. The $20 mystery from Frequency >> Electronics. >> >>>> Thanks Bob >> >>>> Paul >> >>>> WB8TSL >> >>>> >> >>>> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >> >>>> >> >>>>> Hi >> >>>>> >> >>>>> Even for an outer oven, anything below 60C / 140F would be low >> enough >> >> to >> >>>>> run into significant problems. On a mil device, an upper end >> >> temperature >> >>>>> on >> >>>>> the equipment likely would be over 70C. The outer oven would need >> to be >> >>>>> 5 to 10C above that. >> >>>>> >> >>>>> Bob >> >>>>> >> >>>>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> >> wrote: >> >>>>>> >> >>>>>> OK I have had several responses and 110F is low as I expected. >> >>>>>> Wonder if I am being faked out? Perhaps by an inner oven and I am >> only >> >>>>>> reading the outside of the outer oven. The Older URQ10 and newer >> URQ23 >> >>>> do >> >>>>>> have 2 ovens. The meter switch for test is only labeled 1-9. no >> other >> >>>>> clues >> >>>>>> to the function. I noticed 2 positions change with warm up. Sort of >> >>>>>> supports the 2 oven theory. >> >>>>>> Really do not want to take what might be the outer oven off to put >> the >> >>>>>> probe in. >> >>>>>> Thanks everyone. >> >>>>>> Paul >> >>>>>> WB8TSL >> >>>>>> >> >>>>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >> >>>>>> >> >>>>>>> Hi >> >>>>>>> >> >>>>>>> 110 F makes very little sense unless you are in a very cold >> climate. >> >>>>>>> For military gear (or any gear for that matter) 43C on the oven >> just >> >>>>>>> doesn’t work. >> >>>>>>> >> >>>>>>> 110 C would make sense in a very high temperature environment. >> >>>>>>> (think of 85C upper end ….). >> >>>>>>> >> >>>>>>> Bob >> >>>>>>> >> >>>>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> >> wrote: >> >>>>>>>> >> >>>>>>>> Hello to the group. >> >>>>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >> >>>>>>>> Its never worked correctly and in reality some early alpha build. >> >>>>> (Funny >> >>>>>>>> that its labeled 15a) >> >>>>>>>> Looking online there is no documentation that I have been able to >> >>>> find >> >>>>>>> over >> >>>>>>>> the years. >> >>>>>>>> However in another discussion on a AN/URQ-23 that does have a >> manual >> >>>>> and >> >>>>>>>> schematics I realized my guesses on power could be totally wrong. >> >>>> Using >> >>>>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I >> >> was >> >>>>>>> lucky >> >>>>>>>> that I didn't destroy something with my original guess. >> >>>>>>>> That said what I find odd is the internal crystal oven runs at >> >>>> exactly >> >>>>>>> 110 >> >>>>>>>> degrees. Its repeatably warms to that level with a range of >> supply >> >>>> from >> >>>>>>> +/- >> >>>>>>>> 12-15V. >> >>>>>>>> Does 110 degrees F make any sense at all? >> >>>>>>>> Thank you >> >>>>>>>> Paul >> >>>>>>>> WB8TSL >> >>>>>>>> _______________________________________________ >> >>>>>>>> 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. >> >>>>> >> >>>>> >> >>>>> _______________________________________________ >> >>>>> 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. >> >> >> >> >> >> _______________________________________________ >> >> 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. >> >

Paul, from your description, it sounds like it's not an outer and inner oven in the traditional sense, but that the extra heater is to improve things at the weak spot in the Dewar system - the opening, where the high-grade insulation is lost, and conductive things pass through. So maybe it should be called a "dual oven" or "Dewar-compensator" or such. The big question is how are they controlled, and what are the set-points. It could be that the one by the opening is variable, being set to somewhere between the desired inner temperature and ambient. Or, maybe that one is supposed to be 110 deg F constant, and if ambient goes higher, then so be it, and the specs may be looser. BTW are you sure the "110" figure is supposed to indicate a numerical temperature (regardless of units)? Ed

Hi In a dewar flask OCXO, all the heat loss is out the “mouth” of the flask. There is essentially zero energy flow between the inner and outer walls via the “vacuum filled” gap between them. The net result is that if you heat a “plug” in the flask, everything past that plug will be at the same temperature. To do a double oven with a flask, you put two “plugs” in it. Bob > On Feb 12, 2021, at 1:07 PM, paul swed <paulswedb@gmail.com> wrote: > > Well there is no doubt someone has been deep into this unit. Hint missing > screws internally. > But appears both heater windings are ok. > So inner and outer oven has a new meaning. I typically understood this to > be one oven in another oven. Think the HP CS units of old. The same in > other places HP3801. > But in the URQ13 it means there is a long tube. The Dewar flask. The inner > is deep into the flask and the outer is close to the opening. Two > completely separate heaters. Under the outer heater I will guess is the > actual oscillator for the 5 MHz. Further out from the outer heater are the > offset variable caps thermistor for the outer oven a pot and IC. > Several screws hold this outer heater on and considering the risk of taking > out the remainders to look and draw a schematic. > Regards > Paul > > On Fri, Feb 12, 2021 at 11:28 AM paul swed <paulswedb@gmail.com> wrote: > >> Yes Bob they could get hot. But the radio rooms I have been in circa 1970s >> were all air conditioned from destroyers to aircraft carriers. Shirt >> sleeve. The best place to actually be when we were down by the equator was >> the radio room, ET shop, CIC and radar and just maybe the Captain's >> stateroom. But if you were actually there you might still be sweating. >> Chuckle. >> This conversation has given me some good insights. Later today I will >> disable the outer oven. Just curious to see what possible temps might show >> up. Is the inner oven simply reading outer oven leakage. Is there a lead I >> can measure the current of the inner oven.... >> Thanks >> >> On Fri, Feb 12, 2021 at 11:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: >> >>> Hi >>> >>> If it’s 105F “outdoors” that’s 40C. Military gear back in the days of the >>> URQ10 >>> did not live in air conditioned enclosures. It did get deployed to places >>> with >>> temperatures at or above that level. >>> >>> If it’s 40C outdoors, by the time you get to a pile of electronics gear >>> *indoors*, >>> a >10C rise is pretty likely. That drives a very common 50C “upper end” >>> temperature >>> on ground gear in relatively benign installations. >>> >>> This does not just apply to military gear. If you look through test >>> equipment >>> catalogs, a lot of test gear also has the same sort of 50 to 60C upper >>> end spec. >>> The 5065A has a spec of 0 to 50C. The 5061A has the same spec. Both >>> targeted >>> pretty “normal” environments …. ( = they never get below freezing …) and >>> date >>> to the “era” of the URQ10. >>> >>> In this era of HVAC everywhere, the 5071A has a temp range of 0 to 55C. >>> If >>> anything, this would suggest that things still can get pretty hot. >>> >>> Bob >>> >>>> On Feb 12, 2021, at 10:29 AM, paul swed <paulswedb@gmail.com> wrote: >>>> >>>> Bob >>>> OK there is the math. and that all starts to line up. >>>> So most likely for other URQ units there will be an ambient max in the >>>> spec's. At least on the URQ10 in real life even in the hot tropics the >>>> radio room was shirt sleeve temps. >>>> But the question asked was 110 F correct as measured on the outside of >>> the >>>> outer oven against the dewar flask correct. It isn't. The darn thing is >>>> reasonably stable though. >>>> Since the front panel test switch is not labeled I speculate that the >>>> position for the outer oven is in the normal range. The next switch >>>> position most likely is inner and is not in the correct position. It >>> slowly >>>> moves to the high side. >>>> No real details on anything and a total guess. >>>> Really appreciate the thoughts. >>>> Regards >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: >>>> >>>>> Hi >>>>> >>>>> Indeed the outer oven (as a minimum) needs to be 5 to 10 C above >>>>> the maximum ambient. If it’s not it goes out of regulation (runs away) >>>>> and you loose any benefit from it. ( = it now works against you ). >>>>> >>>>> The inner oven as a minimum needs to be 5 to 10 C above the outer >>>>> oven. Again if it is lower, you can / will get into the same runaway >>>>> issue. >>>>> >>>>> Those offsets are dependent on the way things are insulated. If you are >>>>> using a dewar flask, 5C is probably not going to work for you. >>>>> >>>>> Your inner oven *also* is impacted by the turn temperature on the >>> crystal >>>>> being used. This *might* have a 20C range. That would put the maximum >>>>> inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. >>>>> >>>>> Needless to say, if the max ambient is 85C, this will get the inner >>> oven >>>>> components up pretty hot. That’s not a real good idea. Derating the >>> heater >>>>> is pretty easy, derating *everything* in there is much more complex. >>> You >>>>> do not often see 85C upper end double ovens …. >>>>> >>>>> One *could* also ask: “is all this worth it?”. List members *have* >>> written >>>>> papers addressing that point :) >>>>> >>>>> Bob >>>>> >>>>>> On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> >>>>> wrote: >>>>>> >>>>>> Shouldn't the outer oven be cooler than the inner oven except during >>>>>> warmup? I would think the inner electronics would be generating heat. >>>>>> >>>>>> Paul Alfille K1PHA >>>>>> >>>>>> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> >>> wrote: >>>>>> >>>>>>> 50C is what I have sort of seen over the years. Just wondered could >>>>> there >>>>>>> have been a lower temp version. That made no sense. But then this >>> beast >>>>> has >>>>>>> never made a lot of sense. The $20 mystery from Frequency >>> Electronics. >>>>>>> Thanks Bob >>>>>>> Paul >>>>>>> WB8TSL >>>>>>> >>>>>>> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>>>>> >>>>>>>> Hi >>>>>>>> >>>>>>>> Even for an outer oven, anything below 60C / 140F would be low >>> enough >>>>> to >>>>>>>> run into significant problems. On a mil device, an upper end >>>>> temperature >>>>>>>> on >>>>>>>> the equipment likely would be over 70C. The outer oven would need >>> to be >>>>>>>> 5 to 10C above that. >>>>>>>> >>>>>>>> Bob >>>>>>>> >>>>>>>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> >>> wrote: >>>>>>>>> >>>>>>>>> OK I have had several responses and 110F is low as I expected. >>>>>>>>> Wonder if I am being faked out? Perhaps by an inner oven and I am >>> only >>>>>>>>> reading the outside of the outer oven. The Older URQ10 and newer >>> URQ23 >>>>>>> do >>>>>>>>> have 2 ovens. The meter switch for test is only labeled 1-9. no >>> other >>>>>>>> clues >>>>>>>>> to the function. I noticed 2 positions change with warm up. Sort of >>>>>>>>> supports the 2 oven theory. >>>>>>>>> Really do not want to take what might be the outer oven off to put >>> the >>>>>>>>> probe in. >>>>>>>>> Thanks everyone. >>>>>>>>> Paul >>>>>>>>> WB8TSL >>>>>>>>> >>>>>>>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>>>>>>> >>>>>>>>>> Hi >>>>>>>>>> >>>>>>>>>> 110 F makes very little sense unless you are in a very cold >>> climate. >>>>>>>>>> For military gear (or any gear for that matter) 43C on the oven >>> just >>>>>>>>>> doesn’t work. >>>>>>>>>> >>>>>>>>>> 110 C would make sense in a very high temperature environment. >>>>>>>>>> (think of 85C upper end ….). >>>>>>>>>> >>>>>>>>>> Bob >>>>>>>>>> >>>>>>>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> >>> wrote: >>>>>>>>>>> >>>>>>>>>>> Hello to the group. >>>>>>>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >>>>>>>>>>> Its never worked correctly and in reality some early alpha build. >>>>>>>> (Funny >>>>>>>>>>> that its labeled 15a) >>>>>>>>>>> Looking online there is no documentation that I have been able to >>>>>>> find >>>>>>>>>> over >>>>>>>>>>> the years. >>>>>>>>>>> However in another discussion on a AN/URQ-23 that does have a >>> manual >>>>>>>> and >>>>>>>>>>> schematics I realized my guesses on power could be totally wrong. >>>>>>> Using >>>>>>>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I >>>>> was >>>>>>>>>> lucky >>>>>>>>>>> that I didn't destroy something with my original guess. >>>>>>>>>>> That said what I find odd is the internal crystal oven runs at >>>>>>> exactly >>>>>>>>>> 110 >>>>>>>>>>> degrees. Its repeatably warms to that level with a range of >>> supply >>>>>>> from >>>>>>>>>> +/- >>>>>>>>>>> 12-15V. >>>>>>>>>>> Does 110 degrees F make any sense at all? >>>>>>>>>>> Thank you >>>>>>>>>>> Paul >>>>>>>>>>> WB8TSL >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> 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. >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>> >> > _______________________________________________ > 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 According to table 1-2 in: http://www.navy-radio.com/freq/urq-eimb.pdf <http://www.navy-radio.com/freq/urq-eimb.pdf> The URQ-9 and URQ-10 both were rated for 0 to 50C. Per: http://www.navy-radio.com/freq/urq23-MIL-T-28816.pdf <http://www.navy-radio.com/freq/urq23-MIL-T-28816.pdf> The URQ-23 was rated for 0 to 50C I’d say it’s a pretty likely that the URQ-13 was rated to operate over 0 to 50C. It went into the same locations and did the same thing as the other devices. Bob > On Feb 12, 2021, at 1:07 PM, paul swed <paulswedb@gmail.com> wrote: > > Well there is no doubt someone has been deep into this unit. Hint missing > screws internally. > But appears both heater windings are ok. > So inner and outer oven has a new meaning. I typically understood this to > be one oven in another oven. Think the HP CS units of old. The same in > other places HP3801. > But in the URQ13 it means there is a long tube. The Dewar flask. The inner > is deep into the flask and the outer is close to the opening. Two > completely separate heaters. Under the outer heater I will guess is the > actual oscillator for the 5 MHz. Further out from the outer heater are the > offset variable caps thermistor for the outer oven a pot and IC. > Several screws hold this outer heater on and considering the risk of taking > out the remainders to look and draw a schematic. > Regards > Paul > > On Fri, Feb 12, 2021 at 11:28 AM paul swed <paulswedb@gmail.com> wrote: > >> Yes Bob they could get hot. But the radio rooms I have been in circa 1970s >> were all air conditioned from destroyers to aircraft carriers. Shirt >> sleeve. The best place to actually be when we were down by the equator was >> the radio room, ET shop, CIC and radar and just maybe the Captain's >> stateroom. But if you were actually there you might still be sweating. >> Chuckle. >> This conversation has given me some good insights. Later today I will >> disable the outer oven. Just curious to see what possible temps might show >> up. Is the inner oven simply reading outer oven leakage. Is there a lead I >> can measure the current of the inner oven.... >> Thanks >> >> On Fri, Feb 12, 2021 at 11:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: >> >>> Hi >>> >>> If it’s 105F “outdoors” that’s 40C. Military gear back in the days of the >>> URQ10 >>> did not live in air conditioned enclosures. It did get deployed to places >>> with >>> temperatures at or above that level. >>> >>> If it’s 40C outdoors, by the time you get to a pile of electronics gear >>> *indoors*, >>> a >10C rise is pretty likely. That drives a very common 50C “upper end” >>> temperature >>> on ground gear in relatively benign installations. >>> >>> This does not just apply to military gear. If you look through test >>> equipment >>> catalogs, a lot of test gear also has the same sort of 50 to 60C upper >>> end spec. >>> The 5065A has a spec of 0 to 50C. The 5061A has the same spec. Both >>> targeted >>> pretty “normal” environments …. ( = they never get below freezing …) and >>> date >>> to the “era” of the URQ10. >>> >>> In this era of HVAC everywhere, the 5071A has a temp range of 0 to 55C. >>> If >>> anything, this would suggest that things still can get pretty hot. >>> >>> Bob >>> >>>> On Feb 12, 2021, at 10:29 AM, paul swed <paulswedb@gmail.com> wrote: >>>> >>>> Bob >>>> OK there is the math. and that all starts to line up. >>>> So most likely for other URQ units there will be an ambient max in the >>>> spec's. At least on the URQ10 in real life even in the hot tropics the >>>> radio room was shirt sleeve temps. >>>> But the question asked was 110 F correct as measured on the outside of >>> the >>>> outer oven against the dewar flask correct. It isn't. The darn thing is >>>> reasonably stable though. >>>> Since the front panel test switch is not labeled I speculate that the >>>> position for the outer oven is in the normal range. The next switch >>>> position most likely is inner and is not in the correct position. It >>> slowly >>>> moves to the high side. >>>> No real details on anything and a total guess. >>>> Really appreciate the thoughts. >>>> Regards >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Feb 12, 2021 at 10:18 AM Bob kb8tq <kb8tq@n1k.org> wrote: >>>> >>>>> Hi >>>>> >>>>> Indeed the outer oven (as a minimum) needs to be 5 to 10 C above >>>>> the maximum ambient. If it’s not it goes out of regulation (runs away) >>>>> and you loose any benefit from it. ( = it now works against you ). >>>>> >>>>> The inner oven as a minimum needs to be 5 to 10 C above the outer >>>>> oven. Again if it is lower, you can / will get into the same runaway >>>>> issue. >>>>> >>>>> Those offsets are dependent on the way things are insulated. If you are >>>>> using a dewar flask, 5C is probably not going to work for you. >>>>> >>>>> Your inner oven *also* is impacted by the turn temperature on the >>> crystal >>>>> being used. This *might* have a 20C range. That would put the maximum >>>>> inner oven temperature at 10 + 10 + 20 = 40C above the maximum ambient. >>>>> >>>>> Needless to say, if the max ambient is 85C, this will get the inner >>> oven >>>>> components up pretty hot. That’s not a real good idea. Derating the >>> heater >>>>> is pretty easy, derating *everything* in there is much more complex. >>> You >>>>> do not often see 85C upper end double ovens …. >>>>> >>>>> One *could* also ask: “is all this worth it?”. List members *have* >>> written >>>>> papers addressing that point :) >>>>> >>>>> Bob >>>>> >>>>>> On Feb 11, 2021, at 10:05 PM, Paul Alfille <paul.alfille@gmail.com> >>>>> wrote: >>>>>> >>>>>> Shouldn't the outer oven be cooler than the inner oven except during >>>>>> warmup? I would think the inner electronics would be generating heat. >>>>>> >>>>>> Paul Alfille K1PHA >>>>>> >>>>>> On Thu, Feb 11, 2021 at 9:30 PM paul swed <paulswedb@gmail.com> >>> wrote: >>>>>> >>>>>>> 50C is what I have sort of seen over the years. Just wondered could >>>>> there >>>>>>> have been a lower temp version. That made no sense. But then this >>> beast >>>>> has >>>>>>> never made a lot of sense. The $20 mystery from Frequency >>> Electronics. >>>>>>> Thanks Bob >>>>>>> Paul >>>>>>> WB8TSL >>>>>>> >>>>>>> On Thu, Feb 11, 2021 at 8:08 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>>>>> >>>>>>>> Hi >>>>>>>> >>>>>>>> Even for an outer oven, anything below 60C / 140F would be low >>> enough >>>>> to >>>>>>>> run into significant problems. On a mil device, an upper end >>>>> temperature >>>>>>>> on >>>>>>>> the equipment likely would be over 70C. The outer oven would need >>> to be >>>>>>>> 5 to 10C above that. >>>>>>>> >>>>>>>> Bob >>>>>>>> >>>>>>>>> On Feb 11, 2021, at 5:55 PM, paul swed <paulswedb@gmail.com> >>> wrote: >>>>>>>>> >>>>>>>>> OK I have had several responses and 110F is low as I expected. >>>>>>>>> Wonder if I am being faked out? Perhaps by an inner oven and I am >>> only >>>>>>>>> reading the outside of the outer oven. The Older URQ10 and newer >>> URQ23 >>>>>>> do >>>>>>>>> have 2 ovens. The meter switch for test is only labeled 1-9. no >>> other >>>>>>>> clues >>>>>>>>> to the function. I noticed 2 positions change with warm up. Sort of >>>>>>>>> supports the 2 oven theory. >>>>>>>>> Really do not want to take what might be the outer oven off to put >>> the >>>>>>>>> probe in. >>>>>>>>> Thanks everyone. >>>>>>>>> Paul >>>>>>>>> WB8TSL >>>>>>>>> >>>>>>>>> On Thu, Feb 11, 2021 at 5:32 PM Bob kb8tq <kb8tq@n1k.org> wrote: >>>>>>>>> >>>>>>>>>> Hi >>>>>>>>>> >>>>>>>>>> 110 F makes very little sense unless you are in a very cold >>> climate. >>>>>>>>>> For military gear (or any gear for that matter) 43C on the oven >>> just >>>>>>>>>> doesn’t work. >>>>>>>>>> >>>>>>>>>> 110 C would make sense in a very high temperature environment. >>>>>>>>>> (think of 85C upper end ….). >>>>>>>>>> >>>>>>>>>> Bob >>>>>>>>>> >>>>>>>>>>> On Feb 11, 2021, at 2:18 PM, paul swed <paulswedb@gmail.com> >>> wrote: >>>>>>>>>>> >>>>>>>>>>> Hello to the group. >>>>>>>>>>> I have had a AN/URQ-13 or FE-15a oven oscillator for years. >>>>>>>>>>> Its never worked correctly and in reality some early alpha build. >>>>>>>> (Funny >>>>>>>>>>> that its labeled 15a) >>>>>>>>>>> Looking online there is no documentation that I have been able to >>>>>>> find >>>>>>>>>> over >>>>>>>>>>> the years. >>>>>>>>>>> However in another discussion on a AN/URQ-23 that does have a >>> manual >>>>>>>> and >>>>>>>>>>> schematics I realized my guesses on power could be totally wrong. >>>>>>> Using >>>>>>>>>>> voltages like the URQ23 the URQ13 actually behaves fairly well. I >>>>> was >>>>>>>>>> lucky >>>>>>>>>>> that I didn't destroy something with my original guess. >>>>>>>>>>> That said what I find odd is the internal crystal oven runs at >>>>>>> exactly >>>>>>>>>> 110 >>>>>>>>>>> degrees. Its repeatably warms to that level with a range of >>> supply >>>>>>> from >>>>>>>>>> +/- >>>>>>>>>>> 12-15V. >>>>>>>>>>> Does 110 degrees F make any sense at all? >>>>>>>>>>> Thank you >>>>>>>>>>> Paul >>>>>>>>>>> WB8TSL >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> 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. >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> 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. >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>> >> > _______________________________________________ > 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.