[R-1051] Frequency Standard Module

[Bob Camp]

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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