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Discussion of precise time and frequency measurement

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FE-5680A Useful Life

KF
Kris Fredrick
Fri, Aug 16, 2024 3:46 PM

I’m interested in picking up a used FE-5680A Rubidium frequency standard.  I understand many of these are pulled from old cell phone devices.

Anyone know what the useful life of a used device like this might be?  The cost is certainly attractive.  Or is there something else I should consider?

I’m interested in picking up a used FE-5680A Rubidium frequency standard. I understand many of these are pulled from old cell phone devices. Anyone know what the useful life of a used device like this might be? The cost is certainly attractive. Or is there something else I should consider?
BC
Bob Camp
Fri, Aug 16, 2024 5:59 PM

Hi

Typical estimates on “average useful life” are > 10 years. There are a bunch of
footnotes about temperature / other stuff associated with that. Run it hot and it may not
last more than a couple years.

How long did these sit in a cell tower?

How hot did that site get?

At least as important: How long did it sit out in the rain as part of the salvage process?

Various batches hit the China market from various sources. What one batch came out of
and how it was treated may not apply to the next batch.

Best guess: The typical telecom Rb with a proper heatsink on it should last you >5 years
with power applied full time.

How useful one small Rb is vs another one depends a lot on what you intend to do with it.
Some have no 10 MHz output. Others have pretty poor phase noise. Some use really weird
connectors. Does any of that matter? Depends on what you plan on doing with it.

Bob

On Aug 16, 2024, at 11:46 AM, Kris Fredrick via time-nuts time-nuts@lists.febo.com wrote:

I’m interested in picking up a used FE-5680A Rubidium frequency standard.  I understand many of these are pulled from old cell phone devices.

Anyone know what the useful life of a used device like this might be?  The cost is certainly attractive.  Or is there something else I should consider?


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Hi Typical estimates on “average useful life” are > 10 years. There are a bunch of footnotes about temperature / other stuff associated with that. Run it hot and it may not last more than a couple years. How long did these sit in a cell tower? How hot did that site get? At least as important: How long did it sit out in the rain as part of the salvage process? Various batches hit the China market from various sources. What one batch came out of and how it was treated may not apply to the next batch. Best guess: The typical telecom Rb with a proper heatsink on it should last you >5 years with power applied full time. How useful one small Rb is vs another one depends a lot on what you intend to do with it. Some have no 10 MHz output. Others have pretty poor phase noise. Some use really weird connectors. Does any of that matter? Depends on what you plan on doing with it. Bob > On Aug 16, 2024, at 11:46 AM, Kris Fredrick via time-nuts <time-nuts@lists.febo.com> wrote: > > I’m interested in picking up a used FE-5680A Rubidium frequency standard. I understand many of these are pulled from old cell phone devices. > > Anyone know what the useful life of a used device like this might be? The cost is certainly attractive. Or is there something else I should consider? > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com