[R-390] IF sweep alignment

[Stephen M. Murphy]

I have. Sure looks like a crystal filter to me.  But what do I know?

-Steve N8NM

On 02/26/2011 08:54 PM, rbethman wrote:
> 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
>
>