[Elecraft] Mod for optimizing the crystal filter for narrower bandwidths

Wolf-Ruediger Juergens [email protected]
Sun May 25 17:43:53 2003


Hello Bob,

> I've been using this mod since Wayne posted it back in 1999.
> It works very well at the narrowest bandwidths.  I have very
> little extra loss there.

I spent the whole day and check this mod with the big traffic the wpx contest 
makes. On 100Hz bandwith I could receive about all signals without QRM from 
nearby stations. My filters are 700Hz, 400Hz and now 100Hz (220Hz before) and 
there is really no noticeable difference in the level between the different 
filters. That was not the case before I made this mod. The difference in 
signalstrength was about 2 S-Level before. 
I'm absolut satisfied with this mod, it seems that also the CW sounds a bit 
better, but this is maybe only presumption, hi. 

> I'm still using the original crystal set that came with this
> early Field Test unit, s/n 12 :-)  I have the new crystal set
> and will install it along with the other A to B upgrade parts
> when I get some free time.

My A to B Kit is on the way over the ocean :-) 

> In addition, Wolf, I suggest you check out the mod by WO0B,
> that's W O zero B, which help prevent filter leakage.  

I ordered the matched crystal set too. From what I read here from some 
posting, the effect of this mod is not so evident. But I will apply it.

72 de Wolf, DL2WRJ
-- 
Nothing so needs reforming as other people's habits.
                -- Mark Twain, "Pudd'nhead Wilson's Calendar"