[Collins] {Collins} 75A-4 dead on 40 mtrs only - problem solved

[David Propper]

Foster,

You hit the nail on the head !  I got back to work on the 75A-4 this morning after having thoroughly cleaned the band switch with Caig Deoxit  which did not fix the problem.  I went back through the RF alignment and found that the 40 mtr crystal oscillator slug tuned coil was sitting right on the hairy edge of the peak, just past the point where it ceased to oscillate.  Backing the slug off 1/4 turn (as the manual directs) brought 40 mtrs back to life on the receiver.

Thanks very much for calling that to my attention.

Best regards & 73, hope to catch you on the air some time.

Dave, K2DP


> On Apr 23, 2018, at 4:56 PM, Foster <Fosterp at pahrump.com> wrote:
> 
> Hi Dave,
> 	Check the oscillator voltage with your VTVM. The 40 meter adjustment
> is 
> Supposed to be backed down from peak by a quarter turn.
> 	The adjustment procedure is para 9 in the Maintenance chapter. The
> book
> That I grabbed is October 1955 - I can check in a later editions if
> necessary
> 
> 	Good Luck & 73
> Foster W4HCX 
> 
> -
>