[Elecraft] ultimate rejection

[W3FPR - Don Wilhelm]

Merlin,

We have known for some time that the presence of the KSB2 filter reduces the 
ultimate rejection of the CW filter too.  Perhaps you have created a 'cure'. 
Could you put a picture somewhere that we can see it?  If not, I may be able 
to put it up on my website for all to see. (attachments to the reflector 
will be stripped off)

73,
Don W3FPR

----- Original Message ----- 
> ...
> Enough reminiscing;  I just spent about a hour with my KSB2, making  sure
> that the solder connections near the 7 pole filter were filed down, or 
> clipped
> as much as possible, so that they don't act as little "antennas",  thus 
> messing
> up the characteristics of the filter.  It worked!  The  "audio image" that
> one hears when tuning past zero beat got a lot weaker!
>
> Next, I went to local hobby shop and bought some tin.  I made little  tin
> "houses" which I placed around the matching toroids, ground them 
> carefully.  It
> worked too.  Next I added a little tin "fence" which  went on the bottom 
> the
> board, shielding the input of the filter from the  output.  It worked. 
> Three
> times is a charm!
>
> My point:  it ain't rocket science, but the old ideas of keeping RF  away
> from places where it shouldn't be work just as well as they ever did.
>
> I don't have means of measuring this stuff accurately.  Let's just say 
> that
> when tuning across really loud forty meter broadcast stations the filter
> sounds A LOT tighter then it did.
>
> Has anybody else tried this stuff.  There must be hundreds of you old 
> guys
> who have messed with such things.
>
> So, until Elecraft finds a way to put a bulletproof 8 pole filter in its
> magnificent radio it's time to improvise a little.
>
> 73,
>
> Merlin W3ICT