[R-1051] Frequency Standard Module

[paul swed]

Boy I knew there were lots of variations from this group. Sounds like even
more of them. No coils?? Now that really gets interesting. Later version
indeed did use typical dividers and LPFs and if my reference dies I will
simply dump the board and build up the replacement with chips. Though that
may be a while since I do have 2 spares in the basement. There was a period
when I think it was murphey electronics sold them for $25 each. Picked up a
couple.
Good luck
Paul
WB8TSL

On Wed, Dec 31, 2014 at 8:56 AM, Bob Camp <kb8tq at n1k.org> wrote:

> Hi
>
> If you hop in your time machine and have a chat with the guys doing the
> sourcing back in the 70’s and 80’s:
>
> Price was king when it came to the spares contracts. People made spare
> modules who had never had a contract for anything similar. The sole test
> was “did it work in the radio”. How in the world they got approval to
> change circuits - who knows. The result is a pile of 6 modules all for the
> same radio - no two modules even close. If you rip open the OCXO, it’s the
> same kind of thing. The maintenance approach was “swap modules” so the need
> to troubleshoot the innards of a module didn’t figure into the procurement
> process.
>
> Yes it’s crazy. It was crazy at the time and people knew it was crazy at
> the time. Following crazy rules was not unique to that time or place.
>
> Truth in lending - roughly 60% of the people I heard all of that from
> worked for radio outfits.
>
> Bob
>
>
>
> > On Dec 31, 2014, at 7:51 AM, Steve Hobensack <stevehobensack at hotmail.com>
> wrote:
> >
> > Paul
> >
> > I have six modules. Five of them work. None of them have the same
> circuitry. It seems like there are lots of revisions and upgrades, so it
> takes time to reverse engineer the board. This unit in question has no rf
> coupling transformers. It is all ceramic trimmers and cap/resistance tuned
> circuits! I'm guessing it  was made in the late seventies since there is
> also a pair of 14 pin dip ic's in the temperature bridge. Fair Radio still
> sells frequency standard modules. They seem to be repair depot discards.
> It's really a crap shoot on those.
> >
> > Regards
> >
> > Steve N8YE
> >
> >
> >> Date: Tue, 30 Dec 2014 17:08:52 -0500
> >> From: paulswedb at gmail.com
> >> To: r-1051 at mailman.qth.net
> >> Subject: Re: [R-1051] Frequency Standard Module
> >>
> >> Steve
> >> The modules are quite old so lots can go wrong in the regenerative
> >> dividers. Heck how did they ever work in the first place? Black magic.
> >> That said The ceramic caps do oxidize with age and essentially when you
> >> adjust them they can go totally to heck with noisy spots. If possible
> >> obtain replacements I think ceramics are still around and they need to
> be
> >> new. NOS essentially can have the same issue.
> >> I have also seen the coils disintegrate. But that would not cause the
> issue
> >> you are describing.
> >> Good luck in the New Year.
> >> Regards
> >> Paul
> >> WB8TSL
> >>
> >> (snip)
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