Very interesting list. I wonder if that is a way to identify a cross from a manufacturer's P/N (Tek, HP, Fluke, etc.) to a 'real' part? Either that or all you need is a collection of NTE parts and never anything else :). I have used NTE parts to cross to 'unobtanium' in the past and, so far, it's worked. However, my first choice is a 'new' item followed by 'NOS' followed by 'used' then 'anything that will work'. Joe -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Orin Eman Sent: Wednesday, July 24, 2013 11:01 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 10811 update 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 <jltran@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_cybgCFWYV > 7AodJA > sAWQ > > Good luck. > > Joe > > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@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 <paulswedb@gmail.com> wrote: > > > I can hope > > I will embed a k thermocouple also. > > > > > > On Wed, Jul 24, 2013 at 7:45 PM, Bob Camp <lists@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 <paulswedb@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.

NTE is actually a conglomeration of old parts cross reference stuff. Mostly from the TV and radio days. They consolidated the consumer lines of Motorola HEP, RCAs SK, and Sylvanias ECG lines to fill out the replacement device business. Thats when things could be repaired. So thats the reason the 123a can cover a wide range. Its sort of a cross of a cross sort of fits thing. Don't get me at all wrong with these comments. Glad they are around. But it is the reality. Regards Paul WB8TSL On Thu, Jul 25, 2013 at 9:50 AM, J. L. Trantham <jltran@att.net> wrote: > Very interesting list. > > I wonder if that is a way to identify a cross from a manufacturer's P/N > (Tek, HP, Fluke, etc.) to a 'real' part? > > Either that or all you need is a collection of NTE parts and never anything > else :). > > I have used NTE parts to cross to 'unobtanium' in the past and, so far, > it's > worked. However, my first choice is a 'new' item followed by 'NOS' > followed > by 'used' then 'anything that will work'. > > Joe > > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On > Behalf Of Orin Eman > Sent: Wednesday, July 24, 2013 11:01 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] HP 10811 update > > 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 <jltran@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_cybgCFWYV > > 7AodJA > > sAWQ > > > > Good luck. > > > > Joe > > > > -----Original Message----- > > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@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 <paulswedb@gmail.com> wrote: > > > > > I can hope > > > I will embed a k thermocouple also. > > > > > > > > > On Wed, Jul 24, 2013 at 7:45 PM, Bob Camp <lists@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 <paulswedb@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. > > _______________________________________________ > 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. >

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

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 <stefan_heinzmann@gmx.de>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 -- time-nuts@febo.com > 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. >

On 7/25/2013 8:32 PM, paul swed wrote: > Well lucks not so good do have the voltage closer but as Bob C said. That > ain't the issue. this may is a dumb question: Lower than expected frequency means some extra capacitance in parallel or not enough in series with the crystal... ? Would that put suspicion on C4 (0.1uF between crystal and Q1)?

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 <paulswedb@gmail.com> 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 > <stefan_heinzmann@gmx.de>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 -- time-nuts@febo.com >> 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 -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

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 <lists@rtty.us> 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 <paulswedb@gmail.com> 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 > > <stefan_heinzmann@gmx.de>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 -- time-nuts@febo.com > >> 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 -- 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. >

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 <paulswedb@gmail.com> 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 <lists@rtty.us> 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 <paulswedb@gmail.com> 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 >>> <stefan_heinzmann@gmx.de>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 -- time-nuts@febo.com >>>> 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 -- 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.

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 <lists@rtty.us> 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 <paulswedb@gmail.com> 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 <lists@rtty.us> 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 <paulswedb@gmail.com> 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 > >>> <stefan_heinzmann@gmx.de>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 -- time-nuts@febo.com > >>>> 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 -- 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. >

Hi Paul, Did you see this page that talks about tweaking the 10811 oven controller? http://www.realhamradio.com/z3801a-turning-point.htm Ed On 7/26/2013 10:47 AM, paul swed wrote: > 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 <lists@rtty.us> 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 >> >> >>