Collins 51-J

AGC improvement for Collins 51-J.
My AGC circuit was experimented in the two Drake 2-B's and TS-500, it was published in 1980. LA4WN made the few
changes and uses it in his Collins 51-J receiver and reports that he is most satisfied with it.

3a) Collins 51-S AGC improvement. It is easy to improve SSB reception very much, but the problem is that it is
required different AGC time constantsdependent on the modes, such is not provided as it is no mode s
witch for the AGC. The solution is to use an extra relay to switch, the audioand beatoscillator. The the
modeswitch can be rewired for 3 sets of time constants, very slow for SSB, medium for CW, and short for AM.
If you don't use short time-constant for AM you get some hollow effect in the ears when a station fades down.