Hi John,
I use whatever AGC speed band conditions (including QRM and QRN) dictate.
But as you guessed, I normally use SLOW, and the audio derived AGC mod
improves the SLOW AGC the most. I haven't looked at the audio derived mod
yet with my scope, but I presume it substantially speeds up the SLOW attack
time, which is very slow in an unmodified R-390A, about 10 milliseconds. To
eliminate "pops" and "clicks" on initial syllables of SSB transmissions, I
have found that attack times of about 3 milliseconds or less are needed.
Remember, too, that the SLOW AGC of an unmodified R-390A uses a Miller
effect AGC, which has an amazingly slow attack time of 200 milliseconds. I
would be surprised if this audio derived AGC mod worked with SLOW AGC in an
unmodified R-390A. Bur who knows? Maybe someone will try it and report
back to us.
Best regards,
Dallas
----- Original Message -----
From: "John KA1XC" <[email protected]>
To: "Dallas Lankford" <[email protected]>
Sent: Thursday, April 01, 2004 7:25 PM
Subject: Re: [R-390] Wally Chambers (K5OP) Audio Derived AGC
> Hi Dallas,
> sounds interesting. Which AGC speed do you use, Slow?
>> John