[Elecraft] Filters for K3

[Joe Subich, W4TV]

> 
> The 200hz and 250hz cw filters got an equal number of votes, 
> you left me alone on this  ;-)

The filter curves on the Elecraft web site for the 250 Hz show 
the filter to be more than 350 Hz wide (at best) which does 
not provide a significant improvement over the 400 Hz filter. 

On the other hand, the 200 Hz filters regularly measure 190 to 
210 Hz wide at -6dB and when plotted against the "250 Hz" filter 
are consistently "tighter" all the way down in spite of the 
larger shape factor. 

In my opinion, one is wasting money to have both the 400 Hz and 
250 Hz filters ... use 500/200 or 400/200 or 1000/250 depending 
on your needs. 

I also don't know that I would use 250 or 200 Hz filter in the 
sub-receiver.  If one has 500/200 in the main, I would order 
the 200 "matched" to the 500 Hz pair ... or I would simply 
accept the slight mismatch between 200 in the main and a 400 
Hz 8-pole in the sub receiver.  

73, 

   ... Joe, W4TV 
  


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of DM4iM
> Sent: Monday, December 28, 2009 3:25 PM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] Filters for K3
> 
> 
> Elecrafters, thanks for all the input.
> I had many replies, personal mail or via the reflector.
> 
> To sum it up:
> 
> Matched filters are important for diversity.
> 
> 8 votes for the 1.8khz, 4 for the 2.1 ssb filter for 
> contesting. Some use the 1.8khz ssb filter for cw, with the 
> dsp set to narrower bandwith. I think i will order one of 
> those, it makes sense to use it for cw-operation on a quiet 
> band and in ssb contests when things get rough.
> 
> The 200hz and 250hz cw filters got an equal number of votes, 
> you left me alone on this  ;-)
> 
> The expense on 2 matched 5 pole or 2 8-pole filters is about 
> the same, so the criteria here is performance.
> 
> May i call for a run-off?
> 
> Thanks to all es HNY
> 
> Martin
> 
> -- 
> 
> 73, DM4iM 
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