[R-390] Correction To "Chambers Audio Derived AGC Mod"

[Dallas Lankford]

Dan, You have two diodes (and I don't know what else you added, or what else
you removed) in (to/from) your IF deck.  Whatever results I get with my
unmodified IF deck won't tell you anything about your IF deck possible
problems.  A lot of people have written about my AGC mods, and some of them
have gotten it/them wrong.  Maybe you were unlucky and stumbled across one
of those versions.  I would have to dig through my archives, but I believe
there were two (possible three) "Lankford 2 diode AGC mods."  Which one are
you using?  In these recent postings to the QTH R-390A reflector, when I
referred to "my AGC mod" I meant my final one, the one which appeared in HSN
#27.  If you don't have that mod, then K5OP Audio Derived AGC mod probably
won't do anything for you.  Finally, you have only belatedly told me that
your IF deck is not an R-390A IF deck, but a modifier R-390 (non-A) IF deck.
It is likely that is why you are having those problems.

Best regards,

Dallas

----- Original Message -----
From: "Dan Merz" <djmerz@3-cities.com>
To: "Dallas Lankford" <dallas@bayou.com>; "R-390 List"
<r-390@mailman.qth.net>
Sent: Saturday, April 03, 2004 11:11 AM
Subject: Re: [R-390] Correction To "Chambers Audio Derived AGC Mod"


> Dallas,  I changed the K5OP audio agc  gadget to the corrected config and
it
> seems to help a bit on the reduction of distortion on initial attack.  But
that
> aspect wasn't too bad without it with the diode mod in place.  I did the
diode
> mod myself and I'm pretty confident that it's installed the way it should
be.
> My story is a little more complicated than  I stated since I'm using a 390
i.f.
> chassis in my 390a radio but I've convinced myself that this is not the
cause of
> the quirk that I see.  I'll probably wait to see what characteristics you
> observe with your unmodified i.f. chassis as far as carrier meter hang
goes
> since my 390a i.f. chassis also has the diode mod in it and I'd rather not
undo
> the mod at this point and stick it in to see its characteristic.  I would
be
> interested in the observation of anyone else on absence or presence of
this
> quirk of meter hang and whether or not the carrier meter is pinned in a
set with
> or without the diode mod when switching from slow to med on agc.   Dan.