[R-390] 390A AGC

[wa4aos at aol.com]

 Hi Group,

I am working with different AGC mods, 5 so far, that I have found on the web and in ER. The Lankford mod looked most promising initially but I had problems with it bowing diodes but fairly decent AGC when working. Recently I found, with the help of Ray at ER, the W0BY mod listed in issie 208 of ER and it looked very promising as well, however, it still pops on loud signals going quiet. A good example are the morons who tune across the bands with full power, especially annoying if you are coping CW with headphones. I have noticed it on strong SSB signals as well. The article in ER seems to indicate this should not be a problem but yet it is and on 3 different modules wired correctly; perhaps there is something external to the mod that is affecting this AGC mod. I am working with late run EAC modules presently and was wondering if others had had success with an AGC mod that REALLY worked well. I will say that the W0BY mod does work much better than stock 390A AGC.
The Lankford mod as listed on the web is kind of tricky to follow as listed from his hand drawings but I have made many notes and easy to follow schematics.  If  I get the diode problem resolved, I will release my notes to the group if anyone wants them. I tried to contact Dr Lankford but he is not available and I can only ASSUME he would not mind if I offer help to clarify his notes as well as my own experiences and documentation.
 I found the article in ER to be very well written and easy to follow but again that author was not available for questions or comments. Maybe they found something more worthwhile to do with their time instead of playing with 90 pound radios; bass fishing comes to mind. Hi.

I may try increasing the PIV of the diodes that were in the Lankford mod but to date I have had 4) IF modules blow diodes from that mod after some use.
Perhaps implementing SSB compatible AGC with the 390A is not necessary but the receiver has so much going for it that I want to go a step further. I know I am preaching to the choir. Hi
Any thoughts would be appreciated.
Regards,
Glenn WA4AOS