[R-390] IF sweep alignment

[rbethman]

I'd suggest re-looking at the circuitry!

Z-501 is NOT a crystal filter whatsoever!  For personal edification and 
amazement - it happens to be THE 455Kc Oscillator!

The only crystal that has EVER been on/in the IF deck.

It contains ONE 455Kc crystal, a trimmer capacitor to adjust the 
crystal, should it so happen to be a "tad" off, AND the actual slug 
tuned coil for the remainder.  It ties to ONE tube for the purpose of 
creating the ENTIRE 455Kc oscillator that is the HEART of the entire IF 
deck.

I really do wish that folks would "bother" to read the theory and 
operation section of ANY of the manuals regarding the R-390A - BEFORE 
they perform ANY maintenance or alignment.  The alignment BEGINS with 
setting Z-501 ON 455KC.

Bob - N0DGN

On 2/26/2011 8:19 PM, Stephen M. Murphy wrote:
> Y501 on the R-390A is a crystal filter (0.1 KHz.)
>
> -Steve N8NM