[Hallicrafters] Cyclone SR400 questions follow-up

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Thanks to Walt WD0GOF, Sandy AC1Y, Jack W1JHS and James Liles for responding to my queries.

In response to James,

1. When I wind up the AGC pot, the meter pegs left and the meter zero adjustment can't bring it back up (RF gain full CCW or CW) - so I guess I have a problem.

and some new questions:

2. The serial numbers are:
SR400 : 4400xxx  815023 and the chassis is stamped 199813C - xxx requires forensics
PS500A : 750010 746046

Any clues where these fit into the revision levels ?

3. I noticed that the solder joints in my PS500A on the WW resistors R201 & R202 looked a bit "cooked" so I tried reapplying solder.
But my soldering iron has no effect ! Was a special solder used or are the joints just cooked ? P.S. I have 20K rather than 15K resistors.

Cheers
Andrew
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