[time-nuts] AN/URQ-13 FE-15a oscillator question

Bob kb8tq kb8tq at n1k.org
Sat Feb 13 14:14:53 UTC 2021 

Hi

What frequency is it putting out?

Bob

> On Feb 12, 2021, at 9:45 PM, paul swed <paulswedb at gmail.com> wrote:
> 
> I see a glass tape on the inner oven with writing "40.0". Thats it.
> Assuming C its a long way off.The flask is fine the ovens are heating to
> 110F. Both of them. So somethings wrong. Interesting as I peel something
> like caulking off the outer board I see what looks like a opamp. But its a
> FE house number. The top of the can has NSC. The old national semiconductor
> label. Could be a LM709 class opamp.
> 
> On Fri, Feb 12, 2021 at 9:12 PM Bob kb8tq <kb8tq at n1k.org> wrote:
> 
>> Hi
>> 
>> If you are reading something below 60C on a dewar flask outer oven …. it
>> is borken….. very broken.
>> 
>> Bob
>> 
>>> On Feb 12, 2021, at 7:25 PM, paul swed <paulswedb at gmail.com> wrote:
>>> 
>>> The temps I am reading are with a K thermocouple so pretty accurate. I
>> had
>>> simply slid the thermocouple into the flask on the outer edge of the
>>> ovens.The assembly is out of the flask now and both inner and outer are
>>> heating. Will see what they do. Both seem to be heating at about the same
>>> rate. So the great news is the oven windings are not bad. I do see a very
>>> significant voltage difference on two leads that I might guess matter.
>> But
>>> still decoding and reverse engineering everything.
>>> 
>>> On Fri, Feb 12, 2021 at 5:20 PM Bob kb8tq <kb8tq at n1k.org> wrote:
>>> 
>>>> 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

More information about the Time-nuts_lists.febo.com mailing list