sounds like time to add a R across the temp set R. That will lower the R and raise the temp. Its also easy to actually do. Thanks
On Fri, Jul 26, 2013 at 12:08 PM, Bob Camp <[email protected]> wrote: > Hi > > HP spec'd the crystals to be at a < 1x10^-8 / C slope at the marked > temperature on the crystal. The center of the curve should be in the > vicinity of 90C. > > You are ~ -4.5 x 10^-6 low, so that would be > 10 C away from that point > going cold and a bit further going hot. Since the oven is at ~80C, it's not > to hot… > > Bob > > > On Jul 26, 2013, at 10:09 AM, paul swed <[email protected]> wrote: > > > Good comments. Indeed I will order up a new xtal from digi-key. They > should > > be in stock any day now. I do agree with the comment on the cap in > > parallel. I had not thought about the series cap dropping and there is a > > .1uf as I recall. Need to look. The varicap seems to work very well so > > don't believe thats an issue. > > Will do some more hunting. > > By the way as a heads up the top and bottom cover of the xtal compartment > > are actually a pain to screw back together. > > Anyone have a sense of the Hz change per degree C? > > Thanks > > > > > > On Fri, Jul 26, 2013 at 8:52 AM, Bob Camp <[email protected]> wrote: > > > >> Hi > >> > >> Ok, since it's moved *down* and it's about on temperature there are a > >> couple of likely possibilities: > >> > >> 1) The crystal leaks and there's air in it > >> 2) The trap coil(s) / capacitor(s) have changed value > >> 3) The varicap is shorted / forward biased > >> > >> Normal factory troubleshoot (after checking the varicap) would be to > swap > >> the crystal and see if the problem follows the crystal or the > oscillator. > >> Yes, I know, that's not very helpful in this case - sorry about that. > >> > >> Bob > >> > >> On Jul 25, 2013, at 9:32 PM, paul swed <[email protected]> wrote: > >> > >>> Well lucks not so good do have the voltage closer but as Bob C said. > That > >>> ain't the issue. > >>> Darn I hate when he is right. By the way the oscillator draws 26 ma > >> approx > >>> as a reference. Reassembled everything and let the oven heat up it > >> settles > >>> at 81C 15 min after start and within a respectable range of the temps > >>> listed in the service manual. Measured with a K thermocouple. Freq is > at > >>> 9.999955. or 45 Hz low > >>> Tuning the variable cap has 20 Hz range and the cap was pretty much > >> center > >>> range. Have not played with the varicap but that should have a very > small > >>> effect. > >>> I can easily adjust the temp setting R to raise the xtal temp. But that > >>> seems like a jerry rig. > >>> Could a xtal of this quality simply go bad over time? > >>> Somewhat at a loss here. > >>> I have a spare 10544 (Would not use the z3801 outer oven)and wonder if > at > >>> least I could use that with the Z3801. Anyone know if the efc would > work? > >>> Regards > >>> Paul > >>> WB8TSL > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> On Thu, Jul 25, 2013 at 10:28 AM, Stefan Heinzmann > >>> <[email protected]>wrote: > >>> > >>>> paul swed wrote: > >>>> > >>>>> I can't believe you found the transistor. When I pulled it out last > >> night, > >>>>> its actually a MPSA18!!! I had not had time to look it up but figured > >> it > >>>>> was a ebay leftover hunt. :-) > >>>>> At that price I may order 20 of them. Like the gain. > >>>>> > >>>>> Toshiba used to make a transistor with even higher gain, the > >>>> 2SC3112/2SC3113/2SC3295/**2SC4666 (same chip, different package). They > >>>> discontinued it recently, however. > >>>> > >>>> Cheers > >>>> Stefan > >>>> > >>>> > >>>> ______________________________**_________________ > >>>> time-nuts mailing list -- [email protected] > >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/** > >>>> mailman/listinfo/time-nuts< > >> 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. > >> > >> _______________________________________________ > >> 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. > > _______________________________________________ > 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.
