Uniden 78xlw with agc problem

[Harley3315]

I'm going to assume this is an agc issue I have to have the volume full boar to hear any normal static i can hear my locals blasting me out of the chair when they key up. When the other stations I talk to 20 miles out key up I can hardly tell some one had recapped the radio with junk Chinese caps took those back out and put in nitchicon caps for starters it also had been schottkey diode swapped and a 2n2999 in tr7 spot those where all swapped back to stock d1,2,3 have all been changed as well as tr8 tr9 tr10 where to go from here??

 

[Unit 75]

Did you re-align the receive section after you changed those parts out?

 

[Harley3315]

Sure did Unit 75 I've got filter 1 left and filter 2 and fet2 yet to try at this point.

 

[Handy Andy]

Not sure if this has been tried, but if you have RX issues like this - I'd look into VR 1 and the IF amp section it affects as suspected...

A pic of the board I have of a 78' PA-371AB board number...showing where I'd start...


Regards!
:+> Andy <+:

 

[nomadradio]

VR1 is a favorite target for tweakers. Mainly because cranking it full clockwise appears to bring up the receiver sensitivity. Correct adjustment is usually about 1/3 below the full-bore setting. Turning it too high gets you the opposite problem. Excessive noise and a tendency to overload on strong signals.

A louder noise level doesn't allow you to hear anyone any better.

Then again, if someone turned it the wrong way, this will cripple the receiver's sensitivity.

Not sure how much. Never tried it.

73