Hi Richard, It is always wise to be cautious when dealing with an expensive item that could easily be fried by too much voltage and I think you took the correct approach. I found that my oxco seemed to work fine at 12V but, as it has been pointed out, it would probably take a lot longer to reach working temperature and may not be able to maintain that in a cold environment. I've been running mine at 24V for well over a day now and it seems to be working fine so I guess it's OK to keep it on that supply. I guess the case on my unit was slightly hotter under 24V due to the power supply dissipation and I wonder what bearing that makes to the overall heating of the oven. I will try to see if I can get some proper test results of the case temperature than my touch test.
2008/10/2 Richard H McCorkle <[EMAIL PROTECTED]>: > Hi Steve, > > Not knowing the rated voltage of the unit I took the overly cautious > approach of slowly increasing the supply voltage until the frequency > first stabilized when varying the voltage over a small range. The unit > stabilized at approximately 10.8v (12v - 10%) so I specified 12v as > the lower limit of the input voltage required. The internal regulator > will run cooler and the oven will draw more current and take longer > to stabilize at the low end of the usable voltage range. > I didn't test for the maximum voltage as this could turn into a > destructive test if not done properly. I would suspect the internal > regulator can handle input voltages greater than 26.4v (24v + 10%) > safely so the unit could be specified at 24v +/- 10% in the Lucent > application it was designed for. The higher voltage would speed oven > response to changing temperature and reduce the warm-up time. > > Regards, > Richard > > >> Hi Richard, >> >> Many thanks for the info, this was most helpful and I have the unit >> running fine now. The only real difference is that my unit seems to be >> labelled to run off 24V and the data sheet shows 12V. My serial number >> is 2331 (9439) which is not listed on the pdf you sent. After the >> initial panic over running it off 24V for some hours to test it, I >> have tried it on 12V and it still seems to work fine. The difference >> is that the frequency has dropped about .5ppm and the case feels >> cooler to the touch. Now I don't know what the power voltage should be >> as someone else on the list mentioned the nominal is 25.5V. Let's have >> a vote :) >> >> Thanks for your help. >> >> Regards, >> Steve >> >> 2008/9/30 Richard H McCorkle <[EMAIL PROTECTED]>: >>> Hello, >>> >>> I purchased three Piezo 2920136 units and the attached file documents >>> what the pinouts and EFC requirements are. Hope you find this useful. >>> >>> Richard >>> >>> >>>> Just new to this list and found this post while trawling the net for >>>> the same info. This is a manual reply to a previous posting so the >>>> message ids won't tally, sorry. >>>> >>>> --- William Rice wrote:- >>>>> Have a surplus Piezo Crystal Co. oscillator. 3x2x2" with 6 pins on >>>>> bottom, no >>>>> RF >>>>> connector. >>>>> Model# 2920136 / 10.000 Mhz (101728-001) >>>>> Had trouble finding info.... Maybe standard configuration, 9337 stamped on >>>>> unit, >>>>> probably just obsolete. >>>>> Any help appreciated. >>>>> Did find one on ebay, my unit is not as abused. >>>>> Do not know if it needs external control. >>>> >>>>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160286114515 >>>> >>>> I have a Piezo Model 2920136 10MHz oscillator which seems to be the >>>> same as in your url link above. The info I have to date for the six >>>> pins from left to right:- >>>> >>>> Out, GND, +24V, ?, Vcc, GND >>>> >>>> I don't know what the 4th (?) pin does and I also have know idea as to >>>> what voltage needs to be connected to the Vcc pin. Any help please? >>>> >>>> Thanks, >>>> Steve >>>> -- >>>> Steve Rooke - ZL3TUV & G8KVD >>>> Omnium finis imminet >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> >> -- >> Steve Rooke - ZL3TUV & G8KVD >> Omnium finis imminet >> > > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD Omnium finis imminet _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
