[Elecraft] K2: 40m bandpass filter

[Don Wilhelm]

  David,

The 40 meter LPF was changed to an elliptical filter - you can see by 
comparing the old and new circuits.
I am not certain of the reason, but I have assumed that it provides 
better performance for both 50 and 40 meters (better harmonic rejection 
for 60 meters).

73,
Don W3FPR

On 1/15/2011 3:21 AM, David Pratt wrote:
> Don W3FPR:
> A query about C228 a few days ago prompted me to look at my own K2
> manual which does not show C228. Unless my old grey cells deceive me, I
> recall the 40m bandpass filter being changed several years ago. In fact,
> I have found an old envelope in which I have gathered together the
> necessary five capacitors to make the change.
>
> My question is: What was the reason for the change of the 40m bandpass
> filter and is it worth doing?  BTW, I do use my K2 on 60m.
>
> 73 de David G4DMP