[GreenKeys] ST-6 Up & Limping On The Work Bench

[Ralph Mowery]

It may be that some of the resistor values have changed or maybe the wrong 
values were installed when it was built.


----- Original Message ----- 
From: "tony.podrasky" <tony.podrasky at gmail.com>
To: "Green Keys" <greenkeys at mailman.qth.net>
Sent: Monday, March 14, 2016 8:36 PM
Subject: [GreenKeys] ST-6 Up & Limping On The Work Bench


> GE OMs;
>
> I finally got motivated enough to go into the garage
> cabinet and get out some of the stuff to tune-up the ST-6.
>
> Used rubbing alcohol on the loop current rheostat and she's
> working nice and smoothly.
>
> Tried to do the NULL adjustment on the 2 discriminators,
> but couldn't do it. I swapped the LM709 Op-Amps, and one
> of the boards could balance, but the other still can not.
> I swapped a couple more ICs and didn't have much success.
> Went on "everyone's favorite auction site", and although
> some of these "1970's ICs" are selling for $7.00, I
> found a NOS bag of 15 for $12.00.
>
> They should be here some time next week.
>
> More updates as they happen...
>
> UE,
> K2EAA- TONY
> NNNN
> ZCZC
>