Re: [time-nuts] Aging 5065A ?
Bob wrote: > You could also say that with a longer accumulator, you get a closer > approximation to a desired waveform. The width of the accumulator does improve the waveform, but only if you need a frequency between the ones possible with the more narrow accumulator. It goes without saying that the extra bits only have an effect if they are non-zero. Mike write: > I do not believe that is true. Only a longer D/A would result in a closer > approximation to the desired waveform. Adding non-linear bits to the DAC increases noise significantly, because it introduces a periodic effect. This stuff is all easy to simulate with a computer. Try simulating a 12 bit Dac and a 14 bit DAC where the LSB is only half the magnitude it should be. If I were trying to build a high-res DDS, I would calibrate the sine-table to the specific DACs imperfections. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi It would be far easier to just use a (stock) 48 bit chip than to try to get something like that up and running ….. Keeping all the transitions “just right” would be tough. If you don’t do that, you have a major added source of spurs. Bob > On Oct 8, 2020, at 10:14 AM, Lester Veenstra via time-nuts > wrote: > > This I suspect is not original, but with respect for the need for 48 bit > resolution, why not, say, a 24 bit, with reduced range such that it's steps > are the same as what you would see with 48 bits, this stacked (Biased) on a > fixed stable voltage in middle of expected control range. Fixed voltage > could be sourced from an initial courser wide range device. > > Since this seems so obvious, who did it first? > > Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y > les...@veenstras.com > > 452 Stable Ln (HC84 RFD USPS Mail) > Keyser WV 26726 > > GPS: 39.336826 N 78.982287 W (Google) > GPS: 39.33682 N 78.9823741 W (GPSDO) > > > Telephones: > Home: +1-304-289-6057 > US cell+1-304-790-9192 > Jamaica cell: +1-876-456-8898 > > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Hal > Murray > Sent: Wednesday, October 07, 2020 6:18 PM > To: Discussion of precise time and frequency measurement > Cc: hmur...@megapathdsl.net > Subject: Re: [time-nuts] Aging 5065A ? > > > kb...@n1k.org said: >> If you want to run a fixed / well regulated C Field, a DDS with (say) 48 > bits >> would allow you to tune the device well past parts in 10^-15. > > I don't know how to think about a DDS in this context. > > I remember years ago thinking that a DDS was the greatest thing since sliced > > bread. In the context of something like a PPS going into a PC for > timekeeping, that's probably true. You get long term accuracy and the PC > can't see the short term issues. > > But then, somebody mentioned close-in spurs. They get closer the more bits > you have in the DDS magic number. (What is that number called?) > > > Suppose I have a black box labeled "10 MHz" with a cable coming out. > > If you plug that cable into your ADEV measuring setup, can you tell if my > box > has a DDS in it? > > If you plug that cable into your spectrum analyzer, how good a setup do you > need in order to see the spurs? Do they get lost in the close in noise? Or > > maybe the question should be how clean a signal do I need to start with > before > the spurs become visible? Or what should I be asking? > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@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@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
I do not believe that is true. Only a longer D/A would result in a closer approximation to the desired waveform. A longer accumulator will result in being able to use a finer update rate but taking a longer time to do it. I built my first DDS in 1971 and studied their spurious very thoroughly even coming up with algorithms to predict where they would be depending on clock rate and accumulator setting. Of course that was all discrete and I know technology has passed me by. In the 80's I did use off the shelf DDS chips. The limitation was always in the D/A. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Thursday, October 8, 2020 8:15 AM To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] Aging 5065A ? Hi You could also say that with a longer accumulator, you get a closer approximation to a desired waveform. e instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
This I suspect is not original, but with respect for the need for 48 bit resolution, why not, say, a 24 bit, with reduced range such that it's steps are the same as what you would see with 48 bits, this stacked (Biased) on a fixed stable voltage in middle of expected control range. Fixed voltage could be sourced from an initial courser wide range device. Since this seems so obvious, who did it first? Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y les...@veenstras.com 452 Stable Ln (HC84 RFD USPS Mail) Keyser WV 26726 GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home: +1-304-289-6057 US cell +1-304-790-9192 Jamaica cell: +1-876-456-8898 -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Hal Murray Sent: Wednesday, October 07, 2020 6:18 PM To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] Aging 5065A ? kb...@n1k.org said: > If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits > would allow you to tune the device well past parts in 10^-15. I don't know how to think about a DDS in this context. I remember years ago thinking that a DDS was the greatest thing since sliced bread. In the context of something like a PPS going into a PC for timekeeping, that's probably true. You get long term accuracy and the PC can't see the short term issues. But then, somebody mentioned close-in spurs. They get closer the more bits you have in the DDS magic number. (What is that number called?) Suppose I have a black box labeled "10 MHz" with a cable coming out. If you plug that cable into your ADEV measuring setup, can you tell if my box has a DDS in it? If you plug that cable into your spectrum analyzer, how good a setup do you need in order to see the spurs? Do they get lost in the close in noise? Or maybe the question should be how clean a signal do I need to start with before the spurs become visible? Or what should I be asking? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi You could also say that with a longer accumulator, you get a closer approximation to a desired waveform. If you compare the data sheets, the spur levels on the 48 bit parts ad9854.html <https://www.analog.com/en/products/ad9854.html> ad9912.html <https://www.analog.com/en/products/ad9912.html> https://www.analog.com/en/products/ad9956.html <https://www.analog.com/en/products/ad9956.html> are more related to the age of the part than the width when compared to the smaller parts https://www.analog.com/en/products/ad5930.html <https://www.analog.com/en/products/ad5930.html> https://www.analog.com/en/products/ad9834.html <https://www.analog.com/en/products/ad9834.html> Indeed, if you go through the entire page if parts https://www.analog.com/en/parametricsearch/11018#/ <https://www.analog.com/en/parametricsearch/11018#/> There does not appear to be a spur penalty for wider parts. Newer is indeed better, pretty much across the board. Bob > On Oct 7, 2020, at 8:58 PM, Mike Feher wrote: > > It seems to me that now since the register so much longer, yet the D/A is the > same, updates to the D/A will take longer and therefore creating more close > in spurs. That 20logN does suck, but is real. I may suggest running the > output of the DDS through a 5 MHz crystal, or better yet a very narrow > crystal filter. 73 - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -Original Message- > From: time-nuts On Behalf Of Bob kb8tq > Sent: Wednesday, October 7, 2020 7:34 PM > To: Discussion of precise time and frequency measurement > > Cc: hmur...@megapathdsl.net > Subject: Re: [time-nuts] Aging 5065A ? > > Hi > > Well….. the existing synth in the 5065 is no champion spur wise. Coming up > with a DDS that is “as good as” is not all that crazy. > > The 5 MHz reference is multiplied to 6.x GHz and then mixed with the synth. > The close in phase noise of the multiplied signal is mixed with the synth. > The output is the sum of the two. > Going from 5 MHz to 6.x GHz gets you 20 log (N) … a bit over 60 db added > phase noise. > > The synth (at 100 ti 300 Hz offset) needs to be 60 db worse than the noise on > the 5 MHz before it even gets in the game. That’s not a really tough spec to > meet. > > Bob > w the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi, The existing syntesizer is rich on spurs. Very rich in fact. Fairly strong. However these spurs is far enough not to cause much of a problem for the clock, but they will help to demodulate some noise. The noise being problematic is too far in for the spurs of the synthesis to generate any real danger. I replaced the 5.3 MHz syntesis with that from my HP3325B, which for sure isn't free from spurs either, but it turns out that the far in noise was filtered by the lock-up, so I ended improving the phase-noise for the 6.8 GHz synthesis such that the stability out at 1 s was improving by a factor of 2. So, don't over-do it with hunting spurs that ain't going to contribute significantly to the noise and systematics of the box. Increasing resolution is good. Enough bits to the DAC to keep the additional spurs from non-linear mixing down, because that is what truncation of the phase-accumulator state will do and mix the spurs from the current phase-accumulator setting. Step the frequency setting and the spurs move around and the mix products will also move around as with any mixer. As long as that is linear enough, additional spurs will be sufficiently low that we have other things dominating. Cheers, Magnus On 2020-10-08 01:33, Bob kb8tq wrote: > Hi > > Well….. the existing synth in the 5065 is no champion spur wise. Coming up > with a > DDS that is “as good as” is not all that crazy. > > The 5 MHz reference is multiplied to 6.x GHz and then mixed with the synth. > The close in > phase noise of the multiplied signal is mixed with the synth. The output is > the sum of the two. > Going from 5 MHz to 6.x GHz gets you 20 log (N) … a bit over 60 db added > phase noise. > > The synth (at 100 ti 300 Hz offset) needs to be 60 db worse than the noise on > the 5 MHz > before it even gets in the game. That’s not a really tough spec to meet. > > Bob > >> On Oct 7, 2020, at 6:18 PM, Hal Murray wrote: >> >> >> kb...@n1k.org said: >>> If you want to run a fixed / well regulated C Field, a DDS with (say) 48 >>> bits >>> would allow you to tune the device well past parts in 10^-15. >> I don't know how to think about a DDS in this context. >> >> I remember years ago thinking that a DDS was the greatest thing since sliced >> bread. In the context of something like a PPS going into a PC for >> timekeeping, that's probably true. You get long term accuracy and the PC >> can't see the short term issues. >> >> But then, somebody mentioned close-in spurs. They get closer the more bits >> you have in the DDS magic number. (What is that number called?) >> >> >> Suppose I have a black box labeled "10 MHz" with a cable coming out. >> >> If you plug that cable into your ADEV measuring setup, can you tell if my >> box >> has a DDS in it? >> >> If you plug that cable into your spectrum analyzer, how good a setup do you >> need in order to see the spurs? Do they get lost in the close in noise? Or >> maybe the question should be how clean a signal do I need to start with >> before >> the spurs become visible? Or what should I be asking? >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> >> ___ >> time-nuts mailing list -- time-nuts@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@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
It seems to me that now since the register so much longer, yet the D/A is the same, updates to the D/A will take longer and therefore creating more close in spurs. That 20logN does suck, but is real. I may suggest running the output of the DDS through a 5 MHz crystal, or better yet a very narrow crystal filter. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Wednesday, October 7, 2020 7:34 PM To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] Aging 5065A ? Hi Well….. the existing synth in the 5065 is no champion spur wise. Coming up with a DDS that is “as good as” is not all that crazy. The 5 MHz reference is multiplied to 6.x GHz and then mixed with the synth. The close in phase noise of the multiplied signal is mixed with the synth. The output is the sum of the two. Going from 5 MHz to 6.x GHz gets you 20 log (N) … a bit over 60 db added phase noise. The synth (at 100 ti 300 Hz offset) needs to be 60 db worse than the noise on the 5 MHz before it even gets in the game. That’s not a really tough spec to meet. Bob w the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi Well….. the existing synth in the 5065 is no champion spur wise. Coming up with a DDS that is “as good as” is not all that crazy. The 5 MHz reference is multiplied to 6.x GHz and then mixed with the synth. The close in phase noise of the multiplied signal is mixed with the synth. The output is the sum of the two. Going from 5 MHz to 6.x GHz gets you 20 log (N) … a bit over 60 db added phase noise. The synth (at 100 ti 300 Hz offset) needs to be 60 db worse than the noise on the 5 MHz before it even gets in the game. That’s not a really tough spec to meet. Bob > On Oct 7, 2020, at 6:18 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits >> would allow you to tune the device well past parts in 10^-15. > > I don't know how to think about a DDS in this context. > > I remember years ago thinking that a DDS was the greatest thing since sliced > bread. In the context of something like a PPS going into a PC for > timekeeping, that's probably true. You get long term accuracy and the PC > can't see the short term issues. > > But then, somebody mentioned close-in spurs. They get closer the more bits > you have in the DDS magic number. (What is that number called?) > > > Suppose I have a black box labeled "10 MHz" with a cable coming out. > > If you plug that cable into your ADEV measuring setup, can you tell if my box > has a DDS in it? > > If you plug that cable into your spectrum analyzer, how good a setup do you > need in order to see the spurs? Do they get lost in the close in noise? Or > maybe the question should be how clean a signal do I need to start with > before > the spurs become visible? Or what should I be asking? > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
kb...@n1k.org said: > If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits > would allow you to tune the device well past parts in 10^-15. I don't know how to think about a DDS in this context. I remember years ago thinking that a DDS was the greatest thing since sliced bread. In the context of something like a PPS going into a PC for timekeeping, that's probably true. You get long term accuracy and the PC can't see the short term issues. But then, somebody mentioned close-in spurs. They get closer the more bits you have in the DDS magic number. (What is that number called?) Suppose I have a black box labeled "10 MHz" with a cable coming out. If you plug that cable into your ADEV measuring setup, can you tell if my box has a DDS in it? If you plug that cable into your spectrum analyzer, how good a setup do you need in order to see the spurs? Do they get lost in the close in noise? Or maybe the question should be how clean a signal do I need to start with before the spurs become visible? Or what should I be asking? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi If you look at the standard chips that do this, they expand the accumulator. The D/A is limited to the “normal” number of bits based on the max clock frequency. ( = no free lunch …). Bob > On Oct 7, 2020, at 5:37 PM, Mike Feher wrote: > > So, you are increasing the length of the accumulator. What about the D/A > then? 73 - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -Original Message- > From: time-nuts On Behalf Of Bob kb8tq > Sent: Wednesday, October 7, 2020 1:55 PM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Aging 5065A ? > > Hi > > The “normal” 32 bit DDS chips only get you just so far in terms of tuning > resolution. > If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits > would allow you to tune the device well past parts in 10^-15. There are > several DDS chips out there that will do this. Some of the more common ones ( > = what you see on eBay) have issues …. > > Bob > >> On Oct 7, 2020, at 12:11 PM, Mike Feher wrote: >> >> Just curious Bob. What do you mean by higher resolution? Would that be >> a longer accumulator and more bits in the D/A? 73 - Mike >> >> Mike B. Feher, N4FS >> 89 Arnold Blvd. >> Howell NJ 07731 >> 848-245-9115 >> >> -Original Message- >> From: time-nuts On Behalf Of Bob >> kb8tq >> Sent: Wednesday, October 7, 2020 11:11 AM >> To: Discussion of precise time and frequency measurement >> >> Subject: Re: [time-nuts] Aging 5065A ? >> >> Hi >> >> Yup, Bert has lashed up at least one that way ( I have it here in the >> basement). >> I am working on a board with a higher resolution DDS than the typical eBay >> parts. >> >> Bob >> >> ions there. >> >> >> ___ >> time-nuts mailing list -- time-nuts@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@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@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
So, you are increasing the length of the accumulator. What about the D/A then? 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Wednesday, October 7, 2020 1:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Aging 5065A ? Hi The “normal” 32 bit DDS chips only get you just so far in terms of tuning resolution. If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits would allow you to tune the device well past parts in 10^-15. There are several DDS chips out there that will do this. Some of the more common ones ( = what you see on eBay) have issues …. Bob > On Oct 7, 2020, at 12:11 PM, Mike Feher wrote: > > Just curious Bob. What do you mean by higher resolution? Would that be > a longer accumulator and more bits in the D/A? 73 - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -Original Message- > From: time-nuts On Behalf Of Bob > kb8tq > Sent: Wednesday, October 7, 2020 11:11 AM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Aging 5065A ? > > Hi > > Yup, Bert has lashed up at least one that way ( I have it here in the > basement). > I am working on a board with a higher resolution DDS than the typical eBay > parts. > > Bob > > ions there. > > > ___ > time-nuts mailing list -- time-nuts@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@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi The “normal” 32 bit DDS chips only get you just so far in terms of tuning resolution. If you want to run a fixed / well regulated C Field, a DDS with (say) 48 bits would allow you to tune the device well past parts in 10^-15. There are several DDS chips out there that will do this. Some of the more common ones ( = what you see on eBay) have issues …. Bob > On Oct 7, 2020, at 12:11 PM, Mike Feher wrote: > > Just curious Bob. What do you mean by higher resolution? Would that be a > longer accumulator and more bits in the D/A? 73 - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -Original Message- > From: time-nuts On Behalf Of Bob kb8tq > Sent: Wednesday, October 7, 2020 11:11 AM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Aging 5065A ? > > Hi > > Yup, Bert has lashed up at least one that way ( I have it here in the > basement). > I am working on a board with a higher resolution DDS than the typical eBay > parts. > > Bob > > ions there. > > > ___ > time-nuts mailing list -- time-nuts@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Just curious Bob. What do you mean by higher resolution? Would that be a longer accumulator and more bits in the D/A? 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Wednesday, October 7, 2020 11:11 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Aging 5065A ? Hi Yup, Bert has lashed up at least one that way ( I have it here in the basement). I am working on a board with a higher resolution DDS than the typical eBay parts. Bob ions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi Yup, Bert has lashed up at least one that way ( I have it here in the basement). I am working on a board with a higher resolution DDS than the typical eBay parts. Bob > On Oct 7, 2020, at 10:42 AM, paul swed wrote: > > Hi Bob like the DDS pcboards? > > On Wed, Oct 7, 2020 at 10:40 AM Bob kb8tq wrote: > >> Hi >> >> People have successfully mounted eBay synthesizers in 5065’s. They work >> and it is one way to take care of that. >> >> Bob >> >>> On Oct 6, 2020, at 10:49 PM, paul swed wrote: >>> >>> Will agree I would hack something in. The same for the synthesiser. I >> could >>> swear someone on time-nuts already has. The phase detection circuit is >>> audio and it would take some experimentation. I think Corby supplied an >>> alternative approach on the A7 opamp so a lot of good work. >>> But the charcoal problem mentions really would be the worst problem to >> deal >>> with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for >> chuckle? >>> Regards >>> Paul >>> WB8TSL >>> >>> On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: >>> Hi Replacing the synthesizer with something more modern is certainly possible. I have a project (slowly moving along) to do just that. There is nothing crazy >> on the logic board, it could easily be replaced with something more modern for not a lot of money. The phase detector / photo amp / modulator chain is a bit more problematic. My guess is that a replacement of both the photo amp (preamp) and the phase detector at >> the same time would make sense. Both are “audio” circuits. There is nothing in them >> that makes them totally nutty to replace. The physics package *is* the long term question. When the lamps die, I doubt we can find ( or fab) replacements. If the temperature controller fails in a fashion that the entire “tube” turns into a chunk of charcoal, that would be a long tough fixer upper. Fun !!! Bob > On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts < time-nuts@lists.febo.com> wrote: > > > Having been shut of for several months I fired up the > refurbished 5065A a few weeks ago. > > It has since been equipped with a new AC-amplifier > (A7) and a new Rubidium cell with the repaired lamp > (thanks to Corby Dawson) and a receiver with a > TED that was connected according to HP instructions. > > Also the 5 MHz original crystal oscillator has been replaced > with an 10811 upgrade kit. > > Almost immedeately, the FET's in the 60 MHz Multiplier A3 > not replaced during the first repair all failed. > They were replaced with metal can 2N4416 and all was well. > > The next thing that happened was that the amber > pilot light "Continuous Operation" > went out. From just a single event, the lamp started > going out just every time I turned my back on the > instrument. Since there were no sign of out-off lock > conditions and I had no clue other that removing the > logic assy A14 and checking the lamp driver Q18 > (1854-0003, selected from 2N1711) I found the transistor > to be leaky. After replacing it with a 2N1893, I have > only had one single such event in a week. Looking at > the 1854-0003 from the bottom, the TO-5 package is most > likely sealed with brown epoxy. And the A14 board > is littered with them. > > I could of course replace all these > small signal transistors, be it NPN or PNP with modern > types but contemplating on this, I wonder how long a 5065 > can be operational if the heater windings in the Rb cavity > remains OK and the synthesizer with its unobtanium > logics are OK. From the records on the inside > of the meter and switch parts on the front panel, I can > see that the photo current of the original unit > slowly decreased over the years. I have one more > Rb TX unit but the Rb bulb in that one is really "brownish" > and not in any way clear as the one presently used. > > Standard "non-critical" semiconductors can of course > be replaced, even the integrator IC. But what about > transistors in the phase detector assy A8? There > are some oddly looking packages and trying to find > data sheets only returns bad photocopies from > years ago, not really detailing what criteria > I should be looking for. > > Many web-pages from time nuts displays modern > versions of the 5065 (digital clock). The one > in my lab dates back from 1968 so it is over > 50 years old. > > Any research made on possible replacement > types for those exotic semiconductors used > in the critical parts as eg. the phase detector? > Best Regards > Ulf KylenfallSM6GXV > > > > ___ > time-nuts
Re: [time-nuts] Aging 5065A ?
Hi Bob like the DDS pcboards? On Wed, Oct 7, 2020 at 10:40 AM Bob kb8tq wrote: > Hi > > People have successfully mounted eBay synthesizers in 5065’s. They work > and it is one way to take care of that. > > Bob > > > On Oct 6, 2020, at 10:49 PM, paul swed wrote: > > > > Will agree I would hack something in. The same for the synthesiser. I > could > > swear someone on time-nuts already has. The phase detection circuit is > > audio and it would take some experimentation. I think Corby supplied an > > alternative approach on the A7 opamp so a lot of good work. > > But the charcoal problem mentions really would be the worst problem to > deal > > with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for > chuckle? > > Regards > > Paul > > WB8TSL > > > > On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: > > > >> Hi > >> > >> Replacing the synthesizer with something more modern is certainly > >> possible. I have > >> a project (slowly moving along) to do just that. There is nothing crazy > on > >> the logic board, > >> it could easily be replaced with something more modern for not a lot of > >> money. > >> > >> The phase detector / photo amp / modulator chain is a bit more > >> problematic. My guess is that > >> a replacement of both the photo amp (preamp) and the phase detector at > the > >> same time > >> would make sense. Both are “audio” circuits. There is nothing in them > that > >> makes them > >> totally nutty to replace. > >> > >> The physics package *is* the long term question. When the lamps die, I > >> doubt we can find > >> ( or fab) replacements. If the temperature controller fails in a fashion > >> that the entire “tube” > >> turns into a chunk of charcoal, that would be a long tough fixer upper. > >> > >> Fun !!! > >> > >> Bob > >> > >>> On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts < > >> time-nuts@lists.febo.com> wrote: > >>> > >>> > >>> Having been shut of for several months I fired up the > >>> refurbished 5065A a few weeks ago. > >>> > >>> It has since been equipped with a new AC-amplifier > >>> (A7) and a new Rubidium cell with the repaired lamp > >>> (thanks to Corby Dawson) and a receiver with a > >>> TED that was connected according to HP instructions. > >>> > >>> Also the 5 MHz original crystal oscillator has been replaced > >>> with an 10811 upgrade kit. > >>> > >>> Almost immedeately, the FET's in the 60 MHz Multiplier A3 > >>> not replaced during the first repair all failed. > >>> They were replaced with metal can 2N4416 and all was well. > >>> > >>> The next thing that happened was that the amber > >>> pilot light "Continuous Operation" > >>> went out. From just a single event, the lamp started > >>> going out just every time I turned my back on the > >>> instrument. Since there were no sign of out-off lock > >>> conditions and I had no clue other that removing the > >>> logic assy A14 and checking the lamp driver Q18 > >>> (1854-0003, selected from 2N1711) I found the transistor > >>> to be leaky. After replacing it with a 2N1893, I have > >>> only had one single such event in a week. Looking at > >>> the 1854-0003 from the bottom, the TO-5 package is most > >>> likely sealed with brown epoxy. And the A14 board > >>> is littered with them. > >>> > >>> I could of course replace all these > >>> small signal transistors, be it NPN or PNP with modern > >>> types but contemplating on this, I wonder how long a 5065 > >>> can be operational if the heater windings in the Rb cavity > >>> remains OK and the synthesizer with its unobtanium > >>> logics are OK. From the records on the inside > >>> of the meter and switch parts on the front panel, I can > >>> see that the photo current of the original unit > >>> slowly decreased over the years. I have one more > >>> Rb TX unit but the Rb bulb in that one is really "brownish" > >>> and not in any way clear as the one presently used. > >>> > >>> Standard "non-critical" semiconductors can of course > >>> be replaced, even the integrator IC. But what about > >>> transistors in the phase detector assy A8? There > >>> are some oddly looking packages and trying to find > >>> data sheets only returns bad photocopies from > >>> years ago, not really detailing what criteria > >>> I should be looking for. > >>> > >>> Many web-pages from time nuts displays modern > >>> versions of the 5065 (digital clock). The one > >>> in my lab dates back from 1968 so it is over > >>> 50 years old. > >>> > >>> Any research made on possible replacement > >>> types for those exotic semiconductors used > >>> in the critical parts as eg. the phase detector? > >>> Best Regards > >>> Ulf KylenfallSM6GXV > >>> > >>> > >>> > >>> ___ > >>> time-nuts mailing list -- time-nuts@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 --
Re: [time-nuts] Aging 5065A ?
Hi > On Oct 7, 2020, at 10:34 AM, Ulf Kylenfall via time-nuts > wrote: > > Regarding the quest to keep a 5065A running... > > > The 5065 in my hobby corner was equipped with the firstversion of the > AC-Amplifier (A7) that did not have a frequency > selective 2nd harmonic detector. So I copied the later > design but made possible the use of selected polyester > precision audio capacitors for the resonant parts and > also replaced the 709's not with 741's but OP07. > > That design was uploaded to KO4BB (Complete with layout > and gerber /NC-data should anyone want to copy it.) > I have not received any comments but it works > really fine. > > The Rb cavity was equipped with a thermal breaker > recommended by Corby D. The linear power supply > was replaced with a switched 24V unit (with DC filtering!) > and the instrument now runs pretty cool. The only heat > I can feel with my hands are just right above the > Rb cavity. > > I wonder how many 5065A's that are in professional use > today. Or if all have been salvaged by time-nuts... There are apparently one or more “pro” users of the 5065 that gobble them up on eBay. It seems that their needs are small enough that they are ok doing things this way. I *do* find it a bit surprising that nobody makes / sells a “lab grade” Rb anymore. Given its (likely) small market and (certainly) high price it is not a really big surprise …... Bob > > Ulf KylenfallSM6GXV > > ___ > time-nuts mailing list -- time-nuts@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi People have successfully mounted eBay synthesizers in 5065’s. They work and it is one way to take care of that. Bob > On Oct 6, 2020, at 10:49 PM, paul swed wrote: > > Will agree I would hack something in. The same for the synthesiser. I could > swear someone on time-nuts already has. The phase detection circuit is > audio and it would take some experimentation. I think Corby supplied an > alternative approach on the A7 opamp so a lot of good work. > But the charcoal problem mentions really would be the worst problem to deal > with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for chuckle? > Regards > Paul > WB8TSL > > On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: > >> Hi >> >> Replacing the synthesizer with something more modern is certainly >> possible. I have >> a project (slowly moving along) to do just that. There is nothing crazy on >> the logic board, >> it could easily be replaced with something more modern for not a lot of >> money. >> >> The phase detector / photo amp / modulator chain is a bit more >> problematic. My guess is that >> a replacement of both the photo amp (preamp) and the phase detector at the >> same time >> would make sense. Both are “audio” circuits. There is nothing in them that >> makes them >> totally nutty to replace. >> >> The physics package *is* the long term question. When the lamps die, I >> doubt we can find >> ( or fab) replacements. If the temperature controller fails in a fashion >> that the entire “tube” >> turns into a chunk of charcoal, that would be a long tough fixer upper. >> >> Fun !!! >> >> Bob >> >>> On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts < >> time-nuts@lists.febo.com> wrote: >>> >>> >>> Having been shut of for several months I fired up the >>> refurbished 5065A a few weeks ago. >>> >>> It has since been equipped with a new AC-amplifier >>> (A7) and a new Rubidium cell with the repaired lamp >>> (thanks to Corby Dawson) and a receiver with a >>> TED that was connected according to HP instructions. >>> >>> Also the 5 MHz original crystal oscillator has been replaced >>> with an 10811 upgrade kit. >>> >>> Almost immedeately, the FET's in the 60 MHz Multiplier A3 >>> not replaced during the first repair all failed. >>> They were replaced with metal can 2N4416 and all was well. >>> >>> The next thing that happened was that the amber >>> pilot light "Continuous Operation" >>> went out. From just a single event, the lamp started >>> going out just every time I turned my back on the >>> instrument. Since there were no sign of out-off lock >>> conditions and I had no clue other that removing the >>> logic assy A14 and checking the lamp driver Q18 >>> (1854-0003, selected from 2N1711) I found the transistor >>> to be leaky. After replacing it with a 2N1893, I have >>> only had one single such event in a week. Looking at >>> the 1854-0003 from the bottom, the TO-5 package is most >>> likely sealed with brown epoxy. And the A14 board >>> is littered with them. >>> >>> I could of course replace all these >>> small signal transistors, be it NPN or PNP with modern >>> types but contemplating on this, I wonder how long a 5065 >>> can be operational if the heater windings in the Rb cavity >>> remains OK and the synthesizer with its unobtanium >>> logics are OK. From the records on the inside >>> of the meter and switch parts on the front panel, I can >>> see that the photo current of the original unit >>> slowly decreased over the years. I have one more >>> Rb TX unit but the Rb bulb in that one is really "brownish" >>> and not in any way clear as the one presently used. >>> >>> Standard "non-critical" semiconductors can of course >>> be replaced, even the integrator IC. But what about >>> transistors in the phase detector assy A8? There >>> are some oddly looking packages and trying to find >>> data sheets only returns bad photocopies from >>> years ago, not really detailing what criteria >>> I should be looking for. >>> >>> Many web-pages from time nuts displays modern >>> versions of the 5065 (digital clock). The one >>> in my lab dates back from 1968 so it is over >>> 50 years old. >>> >>> Any research made on possible replacement >>> types for those exotic semiconductors used >>> in the critical parts as eg. the phase detector? >>> Best Regards >>> Ulf KylenfallSM6GXV >>> >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@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@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@lists.febo.com > To unsubscribe, go to > http://lists.febo.com
Re: [time-nuts] Aging 5065A ?
Hi With the advent of cheap PCB houses that also do cheap assembly, the ability to cobble up this or that has moved from the “nutty” into the “pretty easy” category. Indeed with very specific parts (integrator cap, fancy op-amp) you might have to hand solder one or two leaded parts on the board. On the integrator, with modern op-amps, there are a lot of parts to pick between. A lot of the stuff that was in the original board went away when HP did the later version of the integrator. Since that board seems to work just fine, I’d stick pretty close to that design. One *might* allow for some larger value integrator caps. I don’t know of many people using the 100 KHz, 1 MHz, or 1 pps outputs from the 5065. Those empty board locations provide a *lot* of room for expansion projects. There’s also the battery charger board and the space for the batteries. To me the clock and clock driver “stuff” is in that same category. it’s a big empty chassis. Not a lot of need to cram extra boards in by double stacking …. Yes, each of us gets to do this their way. I’m sure there are several people raising their hands in exception to at least one item in the paragraph above. I’d still bet at least a half a bottle of beer that something above 80% of the “running in my basement” 5065’s line up pretty well with what’s in that paragraph. If you are going to do compensation on the device, you need to feed that comp in somewhere. Variable C field is one way, but it has it’s issues. A high resolution synth would be another way. In addition to working out the control approach, you probably will want some sort of MCU to filter the data. I’d suggest that one of the “abandoned” board locations is a reasonable place to put all this “stuff”. So, lots of variables, lots of routes from A to B. Bob > On Oct 7, 2020, at 7:09 AM, tim...@timeok.it wrote: > > > Hi, > > I would also like to update the 5065A but so far there are no kits or pcb > available. I think that the first things to update are also the "simplest > ones" like the voltage regulation, the C field generator but first, the > integrator board, because there are many old HP5065A that keep the primordial > version. > > I would like redesign and implement the simplest board, the A9 the > integrator. > > The main features that I have identified are > > 1) the board must be physically compatible with the standard one. > > 2) given the large space, provide for a future daughter board that can > be mounted with columns anchored on the A9. > > 3) smd assembly. > > 4) positive and negative regulators 15V. > > 5) low noise operational amplifier model? > > 6) 5uF capacitor type? > > 7) offset regulation? > > 8) large breadboard area for future changes ex:pressure sensor to > compensate for delta f. > > 9) gold coated connector if possible. > > I would like to have your opinions, and I turn to all the teachers who read > the emails of this group which are many. However, I am available to > collaborate with all those interested in updating the HP5065A. I would like > there to be some common guidelines, once identified, and projects with a > relatively constant flow of work. > > thank you, > > Luciano > > Luciano P. S. Paramithiotti > tim...@timeok.it > www.timeok.it > > Da "time-nuts" time-nuts-boun...@lists.febo.com > A "Discussion of precise time and frequency measurement" > time-nuts@lists.febo.com > Cc "Ulf Kylenfall" ulf_...@yahoo.com > Data Tue, 6 Oct 2020 22:49:30 -0400 > Oggetto Re: [time-nuts] Aging 5065A ? > Will agree I would hack something in. The same for the synthesiser. I could > swear someone on time-nuts already has. The phase detection circuit is > audio and it would take some experimentation. I think Corby supplied an > alternative approach on the A7 opamp so a lot of good work. > But the charcoal problem mentions really would be the worst problem to deal > with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for chuckle? > Regards > Paul > WB8TSL > > On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: > >> Hi >> >> Replacing the synthesizer with something more modern is certainly >> possible. I have >> a project (slowly moving along) to do just that. There is nothing crazy on >> the logic board, >> it could easily be replaced with something more modern for not a lot of >> money. >> >> The phase detector / photo amp / modulator chain is a bit more >> problematic. My guess is that >> a replacement of both the photo amp (preamp) and the phase detector at the >> same time >>
Re: [time-nuts] Aging 5065A ?
Regarding the quest to keep a 5065A running... The 5065 in my hobby corner was equipped with the firstversion of the AC-Amplifier (A7) that did not have a frequency selective 2nd harmonic detector. So I copied the later design but made possible the use of selected polyester precision audio capacitors for the resonant parts and also replaced the 709's not with 741's but OP07. That design was uploaded to KO4BB (Complete with layout and gerber /NC-data should anyone want to copy it.) I have not received any comments but it works really fine. The Rb cavity was equipped with a thermal breaker recommended by Corby D. The linear power supply was replaced with a switched 24V unit (with DC filtering!) and the instrument now runs pretty cool. The only heat I can feel with my hands are just right above the Rb cavity. I wonder how many 5065A's that are in professional use today. Or if all have been salvaged by time-nuts... Ulf KylenfallSM6GXV ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi, I would also like to update the 5065A but so far there are no kits or pcb available. I think that the first things to update are also the "simplest ones" like the voltage regulation, the C field generator but first, the integrator board, because there are many old HP5065A that keep the primordial version. I would like redesign and implement the simplest board, the A9 the integrator. The main features that I have identified are 1) the board must be physically compatible with the standard one. 2) given the large space, provide for a future daughter board that can be mounted with columns anchored on the A9. 3) smd assembly. 4) positive and negative regulators 15V. 5) low noise operational amplifier model? 6) 5uF capacitor type? 7) offset regulation? 8) large breadboard area for future changes ex:pressure sensor to compensate for delta f. 9) gold coated connector if possible. I would like to have your opinions, and I turn to all the teachers who read the emails of this group which are many. However, I am available to collaborate with all those interested in updating the HP5065A. I would like there to be some common guidelines, once identified, and projects with a relatively constant flow of work. thank you, Luciano Luciano P. S. Paramithiotti tim...@timeok.it www.timeok.it Da "time-nuts" time-nuts-boun...@lists.febo.com A "Discussion of precise time and frequency measurement" time-nuts@lists.febo.com Cc "Ulf Kylenfall" ulf_...@yahoo.com Data Tue, 6 Oct 2020 22:49:30 -0400 Oggetto Re: [time-nuts] Aging 5065A ? Will agree I would hack something in. The same for the synthesiser. I could swear someone on time-nuts already has. The phase detection circuit is audio and it would take some experimentation. I think Corby supplied an alternative approach on the A7 opamp so a lot of good work. But the charcoal problem mentions really would be the worst problem to deal with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for chuckle? Regards Paul WB8TSL On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: > Hi > > Replacing the synthesizer with something more modern is certainly > possible. I have > a project (slowly moving along) to do just that. There is nothing crazy on > the logic board, > it could easily be replaced with something more modern for not a lot of > money. > > The phase detector / photo amp / modulator chain is a bit more > problematic. My guess is that > a replacement of both the photo amp (preamp) and the phase detector at the > same time > would make sense. Both are “audio” circuits. There is nothing in them that > makes them > totally nutty to replace. > > The physics package *is* the long term question. When the lamps die, I > doubt we can find > ( or fab) replacements. If the temperature controller fails in a fashion > that the entire “tube” > turns into a chunk of charcoal, that would be a long tough fixer upper. > > Fun !!! > > Bob > > > On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > > > Having been shut of for several months I fired up the > > refurbished 5065A a few weeks ago. > > > > It has since been equipped with a new AC-amplifier > > (A7) and a new Rubidium cell with the repaired lamp > > (thanks to Corby Dawson) and a receiver with a > > TED that was connected according to HP instructions. > > > > Also the 5 MHz original crystal oscillator has been replaced > > with an 10811 upgrade kit. > > > > Almost immedeately, the FET's in the 60 MHz Multiplier A3 > > not replaced during the first repair all failed. > > They were replaced with metal can 2N4416 and all was well. > > > > The next thing that happened was that the amber > > pilot light "Continuous Operation" > > went out. From just a single event, the lamp started > > going out just every time I turned my back on the > > instrument. Since there were no sign of out-off lock > > conditions and I had no clue other that removing the > > logic assy A14 and checking the lamp driver Q18 > > (1854-0003, selected from 2N1711) I found the transistor > > to be leaky. After replacing it with a 2N1893, I have > > only had one single such event in a week. Looking at > > the 1854-0003 from the bottom, the TO-5 package is most > > likely sealed with brown epoxy. And the A14 board > > is littered with them. > >
Re: [time-nuts] Aging 5065A ?
Will agree I would hack something in. The same for the synthesiser. I could swear someone on time-nuts already has. The phase detection circuit is audio and it would take some experimentation. I think Corby supplied an alternative approach on the A7 opamp so a lot of good work. But the charcoal problem mentions really would be the worst problem to deal with. I guess it would be ebay parts. $$$ Whats a dead 5065 go for chuckle? Regards Paul WB8TSL On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote: > Hi > > Replacing the synthesizer with something more modern is certainly > possible. I have > a project (slowly moving along) to do just that. There is nothing crazy on > the logic board, > it could easily be replaced with something more modern for not a lot of > money. > > The phase detector / photo amp / modulator chain is a bit more > problematic. My guess is that > a replacement of both the photo amp (preamp) and the phase detector at the > same time > would make sense. Both are “audio” circuits. There is nothing in them that > makes them > totally nutty to replace. > > The physics package *is* the long term question. When the lamps die, I > doubt we can find > ( or fab) replacements. If the temperature controller fails in a fashion > that the entire “tube” > turns into a chunk of charcoal, that would be a long tough fixer upper. > > Fun !!! > > Bob > > > On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > > > Having been shut of for several months I fired up the > > refurbished 5065A a few weeks ago. > > > > It has since been equipped with a new AC-amplifier > > (A7) and a new Rubidium cell with the repaired lamp > > (thanks to Corby Dawson) and a receiver with a > > TED that was connected according to HP instructions. > > > > Also the 5 MHz original crystal oscillator has been replaced > > with an 10811 upgrade kit. > > > > Almost immedeately, the FET's in the 60 MHz Multiplier A3 > > not replaced during the first repair all failed. > > They were replaced with metal can 2N4416 and all was well. > > > > The next thing that happened was that the amber > > pilot light "Continuous Operation" > > went out. From just a single event, the lamp started > > going out just every time I turned my back on the > > instrument. Since there were no sign of out-off lock > > conditions and I had no clue other that removing the > > logic assy A14 and checking the lamp driver Q18 > > (1854-0003, selected from 2N1711) I found the transistor > > to be leaky. After replacing it with a 2N1893, I have > > only had one single such event in a week. Looking at > > the 1854-0003 from the bottom, the TO-5 package is most > > likely sealed with brown epoxy. And the A14 board > > is littered with them. > > > > I could of course replace all these > > small signal transistors, be it NPN or PNP with modern > > types but contemplating on this, I wonder how long a 5065 > > can be operational if the heater windings in the Rb cavity > > remains OK and the synthesizer with its unobtanium > > logics are OK. From the records on the inside > > of the meter and switch parts on the front panel, I can > > see that the photo current of the original unit > > slowly decreased over the years. I have one more > > Rb TX unit but the Rb bulb in that one is really "brownish" > > and not in any way clear as the one presently used. > > > > Standard "non-critical" semiconductors can of course > > be replaced, even the integrator IC. But what about > > transistors in the phase detector assy A8? There > > are some oddly looking packages and trying to find > > data sheets only returns bad photocopies from > > years ago, not really detailing what criteria > > I should be looking for. > > > > Many web-pages from time nuts displays modern > > versions of the 5065 (digital clock). The one > > in my lab dates back from 1968 so it is over > > 50 years old. > > > > Any research made on possible replacement > > types for those exotic semiconductors used > > in the critical parts as eg. the phase detector? > > Best Regards > > Ulf KylenfallSM6GXV > > > > > > > > ___ > > time-nuts mailing list -- time-nuts@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@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@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aging 5065A ?
Hi Replacing the synthesizer with something more modern is certainly possible. I have a project (slowly moving along) to do just that. There is nothing crazy on the logic board, it could easily be replaced with something more modern for not a lot of money. The phase detector / photo amp / modulator chain is a bit more problematic. My guess is that a replacement of both the photo amp (preamp) and the phase detector at the same time would make sense. Both are “audio” circuits. There is nothing in them that makes them totally nutty to replace. The physics package *is* the long term question. When the lamps die, I doubt we can find ( or fab) replacements. If the temperature controller fails in a fashion that the entire “tube” turns into a chunk of charcoal, that would be a long tough fixer upper. Fun !!! Bob > On Oct 6, 2020, at 3:39 PM, Ulf Kylenfall via time-nuts > wrote: > > > Having been shut of for several months I fired up the > refurbished 5065A a few weeks ago. > > It has since been equipped with a new AC-amplifier > (A7) and a new Rubidium cell with the repaired lamp > (thanks to Corby Dawson) and a receiver with a > TED that was connected according to HP instructions. > > Also the 5 MHz original crystal oscillator has been replaced > with an 10811 upgrade kit. > > Almost immedeately, the FET's in the 60 MHz Multiplier A3 > not replaced during the first repair all failed. > They were replaced with metal can 2N4416 and all was well. > > The next thing that happened was that the amber > pilot light "Continuous Operation" > went out. From just a single event, the lamp started > going out just every time I turned my back on the > instrument. Since there were no sign of out-off lock > conditions and I had no clue other that removing the > logic assy A14 and checking the lamp driver Q18 > (1854-0003, selected from 2N1711) I found the transistor > to be leaky. After replacing it with a 2N1893, I have > only had one single such event in a week. Looking at > the 1854-0003 from the bottom, the TO-5 package is most > likely sealed with brown epoxy. And the A14 board > is littered with them. > > I could of course replace all these > small signal transistors, be it NPN or PNP with modern > types but contemplating on this, I wonder how long a 5065 > can be operational if the heater windings in the Rb cavity > remains OK and the synthesizer with its unobtanium > logics are OK. From the records on the inside > of the meter and switch parts on the front panel, I can > see that the photo current of the original unit > slowly decreased over the years. I have one more > Rb TX unit but the Rb bulb in that one is really "brownish" > and not in any way clear as the one presently used. > > Standard "non-critical" semiconductors can of course > be replaced, even the integrator IC. But what about > transistors in the phase detector assy A8? There > are some oddly looking packages and trying to find > data sheets only returns bad photocopies from > years ago, not really detailing what criteria > I should be looking for. > > Many web-pages from time nuts displays modern > versions of the 5065 (digital clock). The one > in my lab dates back from 1968 so it is over > 50 years old. > > Any research made on possible replacement > types for those exotic semiconductors used > in the critical parts as eg. the phase detector? > Best Regards > Ulf KylenfallSM6GXV > > > > ___ > time-nuts mailing list -- time-nuts@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@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] Aging 5065A ?
Having been shut of for several months I fired up the refurbished 5065A a few weeks ago. It has since been equipped with a new AC-amplifier (A7) and a new Rubidium cell with the repaired lamp (thanks to Corby Dawson) and a receiver with a TED that was connected according to HP instructions. Also the 5 MHz original crystal oscillator has been replaced with an 10811 upgrade kit. Almost immedeately, the FET's in the 60 MHz Multiplier A3 not replaced during the first repair all failed. They were replaced with metal can 2N4416 and all was well. The next thing that happened was that the amber pilot light "Continuous Operation" went out. From just a single event, the lamp started going out just every time I turned my back on the instrument. Since there were no sign of out-off lock conditions and I had no clue other that removing the logic assy A14 and checking the lamp driver Q18 (1854-0003, selected from 2N1711) I found the transistor to be leaky. After replacing it with a 2N1893, I have only had one single such event in a week. Looking at the 1854-0003 from the bottom, the TO-5 package is most likely sealed with brown epoxy. And the A14 board is littered with them. I could of course replace all these small signal transistors, be it NPN or PNP with modern types but contemplating on this, I wonder how long a 5065 can be operational if the heater windings in the Rb cavity remains OK and the synthesizer with its unobtanium logics are OK. From the records on the inside of the meter and switch parts on the front panel, I can see that the photo current of the original unit slowly decreased over the years. I have one more Rb TX unit but the Rb bulb in that one is really "brownish" and not in any way clear as the one presently used. Standard "non-critical" semiconductors can of course be replaced, even the integrator IC. But what about transistors in the phase detector assy A8? There are some oddly looking packages and trying to find data sheets only returns bad photocopies from years ago, not really detailing what criteria I should be looking for. Many web-pages from time nuts displays modern versions of the 5065 (digital clock). The one in my lab dates back from 1968 so it is over 50 years old. Any research made on possible replacement types for those exotic semiconductors used in the critical parts as eg. the phase detector? Best Regards Ulf KylenfallSM6GXV ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
