[Collins] 516F2 Question

[Dr. Gerald N. Johnson]

HV filter choke circuit is shorted, probably the tuning capacitor C1, 
.05 @ 1KV paper. That lets the no load voltage rise higher and makes for 
poor voltage regulation. The tube may be arcing because of the peak 
charging current.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 11/16/2011 10:36 PM, Gary H. Harmon, Jr. wrote:
> Question from a friend:
>
>
>
> HV seems to sag excessively for a second or two under load. and won't come
> completely back up.
>
>
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> Symptom is a weak rectifier (which it is).  But a good rectifier causes fuse
> to blow every time you start up PS.  I suspect that the weak rectifier
> provides enough resistance under load so the PS doesn't arc over, but the
> low resistance of a good rectifier is causing an internal secondary or
> perhaps primary arc. I think I hear the arc when I put in a good rectifier
> and try to start the PS, but it may be just the fuse.
>
>
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> Have tried three known good rectifiers all with same results.
>
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> Have only seen this kind of behavior only once before. Circuit all tests
> good under no load, but breaks down on startup or a load.
>
>
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> I put new caps in but that didn't solve the problem either.
>
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> I took the 32S-1 transmitter over to Skip's house (W5BMK) and we got great
> results with his 516F-2 PS so am 99.9% certain something in either the
> secondary (or possibly primary) of the transformer or one of the filter
> chokes is breaking down.
>
>
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> Any ideas?
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> Gary H. Harmon, Jr. - K5JWK
>
> 6003 Archwood
>
> San Antonio, TX 78239-1504
>
> 210.657.1549h / 210.884.6926c
>
>
>
> "Retirement means every day is a Saturday, except Sunday".
>
>
>