[R-390] C551

[Walter Wilson]

Forrest,

I have found a nice poly cap, 2.2 uF, 630V rated (Mouser part number
5989-630V2.2), that can be squeezed inside the existing can that held C551.
It's a real pain to cut and clean out the old C551 can, so some just solder
the new ones underneath the IF deck.

How do you know that C551 is not up to par.  On a local (steady) AM station,
does the carrier meter reading change between the slow, med, and fast AGC
positions?  If so, I'd agree that C551 is leaking enough to affect
performance.  If the carrier meter reading is the same at all AGC positions,
your problem might not be C551, but rather somewhere else in the AGC
circuit.

Walter Wilson - KK4DF

----- Original Message -----
From: "Forrest Myers" <femyers@attglobal.net>
To: "r-390" <r-390@mailman.qth.net>
Sent: Tuesday, July 08, 2003 9:28 AM
Subject: [R-390] C551


> Hello All,
>  The C551 in my R390a is not quite up to par. I was wondering where a
> suitable replacement may be found. I found a "music" capacitor with axial
> leads that would probably work if I could figure out how to mount it.
Anyone
> had any experience with finding good replacements for that capacitor?
>  Yesterday, I bit the bullet and rebuilt my own filter capacitors. The
> result is not as neat as some I've seen but not too bad. If I ever do it
> again, the result will be much better as I learned a lot from doing it the
> first time. The audio on the radio sounds much cleaner with the new filter
> capacitors installed. Slowly but surely, I'm replacing questionable parts
in
> the radio, Capehart #557. The radio is fully functional but the alignment
is
> off and the PTO is not as linear as I'd like. I figure that after
replacing
> all the questionable caps and bad resisters, I'll tackle the alignment
> problem. In no hurry though.
>  Sure is fun working on such a well built piece of equipment.
>
> Forrest Myers
> AG4ND
>
>
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