[R-390] Re: More AGC Questions

[Dennis L. Wade]

Thanks for the responses.  Some have asked what the problem was, so I'll 
recap my previous post.

By the way, it's the 16 Kc filter that's dead, not the A-OK :(

AGC voltage on most over the air signals is around -4-5 vdc

No signal voltage is about +0.15

Very strong/close BCB station generates about -10, pins the needle, and 
distorts.

Question 1.  I do have a problem, right?

Resistance from AGC jumper to ground 350K with a capacitor charge behavior.

Unplugging the RF deck does not change it.

Unplugging the IF deck puts the jumper at 1.8 meg to ground.

Question 2.  Does this isolate the problem to the IF deck?

Thinking that it does, I figured I'd see the same 350K or less to ground 
from pin 6 (AGC line) of the IF deck connector to ground.  But no, its 
about 7 meg.

This is what's confusing me.

I just received my 7 pin test sockets, so if this heat ever lets up, I 
can take more voltage/resistance readings from V501 502 and 503.

Note that I have not realigned the radio yet, I've recapped the RF deck 
and am working on the IF deck.  I was hoping to solve this ACG problem 
before going in for a full alignment.

	Please excuse the repletion for those who saw the previous posts.

		Thanks for the help.

                  Sign me Frustrated in Carmichael,

                            Dennis

(p.s. sorry about all the typos in the post below. Apparently I was in a 
bigger hurry than I thought.)

Dennis L. Wade wrote:
> Hi all,
> 
>      In attempting to keep my sanity, I've been 
> looking further at the IF deck I have on the bench to 
> figure out why I might have low AC.
> 
>      I discovered that my A-OK filter is dead.  Could 
> this drag the AC line down?  If it did, wouldn't I 
> see that on an ohmmeter test?  The AC line in the deck 
> doesn't show excessive leakage to ground however.
> 
>      This deck is frustrating me because its not 
> behaving like it has a problem in terms of the 
> resistance checks I've done.
> 
>            Thanks for any help,
> 
>             Dennis
> ---------------
> Dennis Wade
> KG6ZI
> Carmichael, CA
> 
> 

-- 
--------
Dennis L. Wade
KG6ZI
Carmichael, CA