[R-390] C553 replacement?

[Jim Whartenby]

A quick look at the R-390 Collins preliminary manual indicates that C-606 and C-608 are both rated at 100 vdcw.  Curious that C-608 has 174 volts across it according to the voltage table for V-607.  

I did not find C553, which tube is associated with it?

Regards,
Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy

-----Original Message-----
From: Barry <n4buq at knology.net>
To: John Wendler <wendlerjrv at gmail.com>
Cc: R-390 Mailing List <r-390 at mailman.qth.net>
Sent: Sat, Feb 25, 2023 8:52 pm
Subject: Re: [R-390] C553 replacement?

If I'm not mistaken, Dave Medley (and others) suggest that 180v regulator issues in the R390 might be due to leakage in C606 and/or C608 and I think those are typically Vitamin Q capacitors.

Thanks,
Barry - N4BUQ

----- Original Message -----
> From: "John Wendler" <wendlerjrv at gmail.com>
> To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> Sent: Saturday, February 25, 2023 6:01:07 PM
> Subject: [R-390] C553 replacement?

> The C553 in one of my IF modules is a Sangamo Vitamin Q capacitor, 0.01 uF,
> 300 V.  It looks good visually and is not a Brown or Black Beauty of
> Death.
> 
> What's the group experience with the reliability of the Vitamin Q caps?
> 
> V/r,
> 
> JP N5CQU
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