[Elecraft] K3 filters

[Joe Subich, W4TV]

> I would like the 250 hz 8 pole filter for cw. Should I also get 
> the 400 hz filter for ssb.

The 400 Hz filter is far too narrow to be useful in SSB - you don’t 
want a bandwidth less than 1500 to 1800 Hz for voice use although 
bandwidths as low as 800 - 1000 Hz may be useful for some digital 
modes.  

I would not recommend both the 400 Hz and 250 Hz in the same radio. 
The reference plots for the 250 Hz and 40 Hz filters on the Elecraft 
web site: http://www.elecraft.com/K3/K3_8_pole_plots.htm show the 
250 Hz filter to have a bandwidth of 370 Hz and the 400 Hz filter 
to have a bandwidth of 435 Hz.  

There is not enough difference between the 250 and 400 Hz filters 
for you to notice in actual operation. 

73, 

   ... Joe, W4TV 
  



> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Scott McDowell
> Sent: Saturday, August 30, 2008 11:32 PM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] K3 filters
> 
> 
> I have a k3/100 ordered and am trying to decide on filters. I 
> would like the 250 hz 8 pole filter for cw. Should I also get 
> the 400 hz filter for ssb. Scott N5SM