HP 5061Bs on ebay
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
Hi
There are a lot of 5061 chassis running around. There are very few working
tubes to go with those chassis. The tubes wear out, but the chassis gets kept
“just in case”.
It is not unusual to buy a half dozen or more in order to find one with a tube that
“kinda sorta” works. Many of the ones that do get running are not very close to
their original spec performance. (The stability of the unit degrades as the tube
wears out …..)
For a while FEI had a contract to supply replacement tubes to the US government.
You will find those tubes in some units. You also will find units with tubes out of other
brands of Cs standards. How well those work is a bit of a “that depends” sort of thing.
None of this is to say “don’t do this”. It only is a caution that the route from having
nothing to having a good performance unit may be pretty long. You might get lucky
early on …..
Bob
On Jun 14, 2023, at 6:09 PM, Ke-Fong Lin via time-nuts time-nuts@lists.febo.com wrote:
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Totally agree with the comments its a real gamble. Even if it says the tube
works what does that mean? The beams high enough to lock. I can tell you
the beam can be unreadable and the system will lock. I have a 5061 unit
with 0 beam and the metering circuit is not bad.
That gets to Bobs comments well its locked but how good. The noise is
higher and the stability is noisey. It can be seen using a good reference
and a scope. But on average it tends to stay put.
The unfortunate reality is the asking price is something but at 60 LBs the
shipping is expensive.
By all means go for it. It has been a great education for me at least
working with the 5061s and FTS.
But go in eyes wide open.
Good luck to you.
Paul
WB8TSL
On Thu, Jun 15, 2023 at 1:44 AM Bob Camp via time-nuts <
time-nuts@lists.febo.com> wrote:
Hi
There are a lot of 5061 chassis running around. There are very few
working
tubes to go with those chassis. The tubes wear out, but the chassis gets
kept
“just in case”.
It is not unusual to buy a half dozen or more in order to find one with a
tube that
“kinda sorta” works. Many of the ones that do get running are not very
close to
their original spec performance. (The stability of the unit degrades as
the tube
wears out …..)
For a while FEI had a contract to supply replacement tubes to the US
government.
You will find those tubes in some units. You also will find units with
tubes out of other
brands of Cs standards. How well those work is a bit of a “that depends”
sort of thing.
None of this is to say “don’t do this”. It only is a caution that the
route from having
nothing to having a good performance unit may be pretty long. You might
get lucky
early on …..
Bob
On Jun 14, 2023, at 6:09 PM, Ke-Fong Lin via time-nuts <
time-nuts@lists.febo.com> wrote:
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack
thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
There were also late model 5061Bs that used the compact tube, which was a modified 5071A tube, I.E. different harness and EPROMs.
I agree when looking at a used cesium standard one should assume it is near or at "end of life" but that said personally I found a surprising number of cesium standard that the tube was excellent and the issue was related to other issues, some minor as cap failures. But ultimately CBT life is about 4-6 years for a High-Performance CBT and 8-15 years for a standard CBT. So, for us Time-Nuts it is an expensive hobby.
Cheers;
Tom Knox
SR Test and Measurement Engineer
Phoenix Research
4870 Meredith Way Apt 102
Boulder, Co 80303
Formerly of:
357 Fox Lane
Superior Co 80027
303-554-0307
actast@hotmail.com
"Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein
From: Bob Camp via time-nuts time-nuts@lists.febo.com
Sent: Wednesday, June 14, 2023 8:14 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: Ke-Fong Lin anotherlin@gmail.com; Bob Camp kb8tq@n1k.org
Subject: [time-nuts] Re: HP 5061Bs on ebay
Hi
There are a lot of 5061 chassis running around. There are very few working
tubes to go with those chassis. The tubes wear out, but the chassis gets kept
“just in case”.
It is not unusual to buy a half dozen or more in order to find one with a tube that
“kinda sorta” works. Many of the ones that do get running are not very close to
their original spec performance. (The stability of the unit degrades as the tube
wears out …..)
For a while FEI had a contract to supply replacement tubes to the US government.
You will find those tubes in some units. You also will find units with tubes out of other
brands of Cs standards. How well those work is a bit of a “that depends” sort of thing.
None of this is to say “don’t do this”. It only is a caution that the route from having
nothing to having a good performance unit may be pretty long. You might get lucky
early on …..
Bob
On Jun 14, 2023, at 6:09 PM, Ke-Fong Lin via time-nuts time-nuts@lists.febo.com wrote:
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
I think is one of them Bert Kehren
In a message dated 6/15/2023 4:46:03 PM Eastern Standard Time, time-nuts@lists.febo.com writes:
There were also late model 5061Bs that used the compact tube, which was a modified 5071A tube, I.E. different harness and EPROMs.
I agree when looking at a used cesium standard one should assume it is near or at "end of life" but that said personally I found a surprising number of cesium standard that the tube was excellent and the issue was related to other issues, some minor as cap failures. But ultimately CBT life is about 4-6 years for a High-Performance CBT and 8-15 years for a standard CBT. So, for us Time-Nuts it is an expensive hobby.
Cheers;
Tom Knox
SR Test and Measurement Engineer
Phoenix Research
4870 Meredith Way Apt 102
Boulder, Co 80303
Formerly of:
357 Fox Lane
Superior Co 80027
303-554-0307
actast@hotmail.com
"Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein
From: Bob Camp via time-nuts time-nuts@lists.febo.com
Sent: Wednesday, June 14, 2023 8:14 PM
To: Discussion of precise time and frequency measurement time-nuts@lists.febo.com
Cc: Ke-Fong Lin anotherlin@gmail.com; Bob Camp kb8tq@n1k.org
Subject: [time-nuts] Re: HP 5061Bs on ebay
Hi
There are a lot of 5061 chassis running around. There are very few working
tubes to go with those chassis. The tubes wear out, but the chassis gets kept
“just in case”.
It is not unusual to buy a half dozen or more in order to find one with a tube that
“kinda sorta” works. Many of the ones that do get running are not very close to
their original spec performance. (The stability of the unit degrades as the tube
wears out …..)
For a while FEI had a contract to supply replacement tubes to the US government.
You will find those tubes in some units. You also will find units with tubes out of other
brands of Cs standards. How well those work is a bit of a “that depends” sort of thing.
None of this is to say “don’t do this”. It only is a caution that the route from having
nothing to having a good performance unit may be pretty long. You might get lucky
early on …..
Bob
On Jun 14, 2023, at 6:09 PM, Ke-Fong Lin via time-nuts time-nuts@lists.febo.com wrote:
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
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To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi
Yet another layer to this will always be “what’s the objective?”.
If the goal is simply to have a Cs and play with it, then indeed the 5061 is a good
target. Going after a 5071 is a step up in cost. There is no problem with this being
the objective.
If the goal is some level of accuracy / stability / ADEV then this gets more way
more complex. Some form of disciplined Rb quickly makes its way onto the list
of things you look at. Even with a GPS (and it’s cost) attached, the Rb likely will
be competitive both in terms of cost and performance. Rb’s wear out, but the
typical used item likely lasts longer than a used Cs.
Lots of choices.
Bob
On Jun 15, 2023, at 8:55 AM, paul swed paulswedb@gmail.com wrote:
Totally agree with the comments its a real gamble. Even if it says the tube works what does that mean? The beams high enough to lock. I can tell you the beam can be unreadable and the system will lock. I have a 5061 unit with 0 beam and the metering circuit is not bad.
That gets to Bobs comments well its locked but how good. The noise is higher and the stability is noisey. It can be seen using a good reference and a scope. But on average it tends to stay put.
The unfortunate reality is the asking price is something but at 60 LBs the shipping is expensive.
By all means go for it. It has been a great education for me at least working with the 5061s and FTS.
But go in eyes wide open.
Good luck to you.
Paul
WB8TSL
On Thu, Jun 15, 2023 at 1:44 AM Bob Camp via time-nuts <time-nuts@lists.febo.com mailto:time-nuts@lists.febo.com> wrote:
Hi
There are a lot of 5061 chassis running around. There are very few working
tubes to go with those chassis. The tubes wear out, but the chassis gets kept
“just in case”.
It is not unusual to buy a half dozen or more in order to find one with a tube that
“kinda sorta” works. Many of the ones that do get running are not very close to
their original spec performance. (The stability of the unit degrades as the tube
wears out …..)
For a while FEI had a contract to supply replacement tubes to the US government.
You will find those tubes in some units. You also will find units with tubes out of other
brands of Cs standards. How well those work is a bit of a “that depends” sort of thing.
None of this is to say “don’t do this”. It only is a caution that the route from having
nothing to having a good performance unit may be pretty long. You might get lucky
early on …..
Bob
On Jun 14, 2023, at 6:09 PM, Ke-Fong Lin via time-nuts <time-nuts@lists.febo.com mailto:time-nuts@lists.febo.com> wrote:
Hi everyone,
So unfortunately, no, I won't be able to buy the newly introduced
5071B (or rather revamped 5071A) :)
However, and you probably know already, there's a few 5061Bs from one
particular seller.
They're pretty tempting, and I'm considering making an offer.
They seem to be later models (late 80s), and some of them even have
"tube good" or "tube ok" sticker on them.
Some are missing bits and pieces (like HV supplies) but with the
cesium tube. And it seems that parts other than the cesium tube, are
easy to find (lots of 5061 with dead tubes to scavange from).
A few seem even customized, perhaps by Frequency Electronics? For
internal use? Seems that they've added some monitoring circuitry.
Any comment, especially on the tubes, their remaining life or lack thereof?
Still a project, but that's really something I start considering.
Best regards,
--
/* Lin Ke-Fong
- anotherlin@gmail.com mailto:anotherlin@gmail.com
- I always do what I say, especially if it's something stupid.
*/
time-nuts mailing list -- time-nuts@lists.febo.com mailto:time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com mailto:time-nuts-leave@lists.febo.com
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