[Drake] Couple of questions

[Martin Sole]

Interesting question time. The Drake manual states 10dB signal to noise
at 0.25uV. Is that 0.25uV p.d. or e.m.f? I think Americans use terms
like soft and hard micovolts, never sure which is which. I understand
p.d. (potential difference) being the voltage across one of two loads,
50 ohms from the receiver and 50 ohms from the sig gen, with e.m.f being
open circuit volts from the generator with no additional external load.

Second question. Does anybody know what the W3RJ AGC mod is, or was.
I've seen it mentioned a couple of times but can find no details on it,
is it worthy?

Martin, HS0ZED
Bangkok