I find it hard to believe that NTE spec the 123AP to replace a transistor with min beta of 500...
This is quite entertaining: http://www.vetco.net/catalog/product_info.php?products_id=1856 Look at the parts it's supposed to replace. (Nothing against Vetco - they are a great source of NTE components and are local to me. They are just quoting what NTE claim.) Orin. On Wed, Jul 24, 2013 at 8:42 PM, J. L. Trantham <jlt...@att.net> wrote: > The 2N6429 crosses to an NTE123AP, in stock at Allied for $0.80. > > > http://www.alliedelec.com/search/productdetail.aspx?SKU=70214870&mkwid=szEc5 > > jMBI&pcrid=23468365337&pkw=nte123ap&pmt=e&pdv=c&gclid=CKyzu9_cybgCFWYV7AodJA > sAWQ > > Good luck. > > Joe > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of paul swed > Sent: Wednesday, July 24, 2013 8:29 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] HP 10811 update > > Well learned quite a bit Q4 does have an issue. Further there is a reason > it > has such high Beta. Its must deliver 30 ma to the oscillator and buffer. > I was quite surprised by this current level. I was guessing the oscillator > was a few mils and the buffer maybe 8. > The 2n3904 simply does not cut it. Need to do some digging in the ole > transistors. > Regards > Paul. > > > On Wed, Jul 24, 2013 at 8:06 PM, paul swed <paulsw...@gmail.com> wrote: > > > I can hope > > I will embed a k thermocouple also. > > > > > > On Wed, Jul 24, 2013 at 7:45 PM, Bob Camp <li...@rtty.us> wrote: > > > >> Hi > >> > >> The regulator should be fixed, and the OCXO will work better with it > >> repaired. That said, shifting the regulated voltage from 5.7 to 5.27 > >> volts should not shift that oscillator 45 Hz. > >> > >> Bob > >> > >> On Jul 24, 2013, at 9:00 AM, paul swed <paulsw...@gmail.com> wrote: > >> > >> > Hello to the group. Numbers of threads running on the HP 10811. > >> > Mine is > >> 45 > >> > Hz low. The oven is most likely ok. I did get the can open per the > >> various > >> > other threads and the web pix. Started testing the circuits and > >> > have > >> found > >> > that the regulator for the oscillator isn't. Its supposed to > >> > produce > >> 5.7V > >> > and is at 5.27V thats pretty significant. The transistor looks like > >> > a shorted collector base junction. Though I do not have it out of > >> > circuit yet. Its Q4 a 2n6429. What interesting about this > >> > transistor is its > >> beta at > >> > 1 ma is 500 min and max is 1300. Its not a darlington. Thats pretty > >> > amazing. I am looking through my xsistors to find something close. > >> > May > >> just > >> > through a 2n3904 in for a quick test. Its beta is nothing like the > 6429. > >> > But it would help to prove/disprove the point that the low V may be > >> > offsetting the oscillator I hope. > >> > Will also embed a K thermal couple to verify the oven really is in > >> > the 80-84C region. > >> > Regards > >> > Paul. > >> > WB8TSL > >> > _______________________________________________ > >> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> > and follow the instructions there. > >> > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.