[R-390] IF sweep alignment

[Tom Frobase]

TM-5820-358-35 Chapter 14. Crystal Filter say's it is?



On 2/26/2011 7:54 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
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