[Hallicrafters] SR-400A power output

[Alexander N. Gerli]

Hello, Friends,

I'm starting to think about realigning my SR-400A. Hears just fine, but the
power out isn't where it should be. I have several pairs of 6KD6s I can use
besides the pair in the rig.

First of all, the present PA tubes appear to be balanced OK. I can get them
adjusted to within .425 and .427Vdc on J11 and J12 with the rig tuned for
as near 300mA as I can achieve.

What is strange is that my max PO into my Waters metered DL is about 80W in
CW mode. No way that's right. If I go to LSB for instance, and whistle, I
can get easily 175W. This is using 7250kHz. Can't explain the big
difference, except for a need for realignment of the driver stages? I
haven't used the rig for about six months. And, over the past two days,
I've been on several favorite nets with good signal reports. But the PO
seems to be in the tank. Probably needs to have the neutralization checked
as well?

​73,​
​​


​Sandy AC1Y​


Alexander N. Gerli, Sr.
548 Allred Mill Road
Mount Airy, NC 27030-2202

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