[Elecraft] IF xtal replacement mod

[Phil Wheeler]

Hmmm .. all of this is making me wonder if I want to replace my xtals. 
 I have all 14 on hand, but I have no receive problems on CW with the 
existing set -- even setting the filter at 70 Hz gives no audible 
attenuation to a properly tuned CW signal.

What to do, what to do?  :)

73, Phil (S/N #380)

Vic Rosenthal wrote:

>"David A. Belsley" wrote:
>  
>
>>Well, I replaced the 7 IF xtals and redid CAL FIL with spectrum analyzer.
>>I guess the results are good, although I didn't do any before and after
>>measurements.  The only negative is that my FL4 position, at 100Hz, is now
>>much more attenuated relative to the other BPs, roughly one S unit.  It was
>>somewhat less than the others before the mod, but not that much.  Any
>>thoughts out there?
>>    
>>
>
>I found (in my case, both before and after replacing the crystals) that the
>attenuation increased sharply when the filter width was less than about 200 Hz,
>and that the actual bandwidth as viewed on spectrogram did not appear to narrow
>so much.  So I settled on 220 Hz as my narrowest filter.  Incidentally, I used
>220 rather than 200 because at this bandwidth the pitch of the signal centered
>in this filter did not vary from the others.
>
>73
>Vic K2VCO
>



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