I dont trust any electrolytic that is 30 or so years old. At $13 and change
each I bought new ones from Ameritron and also replaced the equalizers.
A big problem with many 76's is the C-109 tantalum, C-108 electrolytic,
R-116 (go to a 1W), and R-124 a 2W carbon that drifts up in value to the
point K-6 never activates.
Carl
KM1H
----- Original Message -----
From: "Colin Lamb" <k7fm@teleport.com>
To: <amps@contesting.com>
Sent: Monday, September 12, 2011 4:43 PM
Subject: Re: [Amps] Alpha 76a
> "One thing you might consider if you haven't already is replacing the
> power supply HV filter caps. They are more than ready One thing you might
> consider if you haven't already is replacing the power supply HV filter
> caps."
>
> Two weeks ago, I had my Alpha 76A apart and decided to check out the
> electrolytics and bleeder resistors. I removed each capacitor and checked
> them with a capacitance meter and and ESR meter. I also measured the
> leakage current under load. The amp had not been used for years, but
> after forming for a few minutes, the leakage current dropped to almost
> nothing. Measured capacitance was within a couple percent.
>
> These caps are high quality original caps and did not need replacement.
> Although I have found other amps that needed replacement caps, the Alphas
> have held up well. Worthwhile to try them before replacement.
>
> 73, Colin K7FM
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1392 / Virus Database: 1520/3892 - Release Date: 09/12/11
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|