[Elecraft] 250 Hz and 400 Hz Filter Measurements

[Richard Ferch]

As someone who mainly operates during CW and RTTY contests, I draw a 
slightly different conclusion from Craig's and Jim's. In the absence of 
a true 270 Hz roofing filter, the existing "250 Hz" filter appears to be 
the best roofing filter option on offer for RTTY contest use. Therefore, 
while I agree with Ed's conclusion about these two filters, of the two 
the one that is unnecessary for me is the 400 Hz filter.

 From amongst the existing choices, a 500/250 combination seems most 
effective for my situation. If I were more heavily into 160 CW as 
compared with RTTY, I might opt for a 400/200 combination instead. For a 
single roofing filter for CW/RTTY use, you might find a 400 to be the 
best single-filter compromise. Different solutions for different situations.

73,
Rich VE3KI


Craig AC0DS wrote:

> I agree with you that there is no need for the 250 Hz 8 pole
> option.

Jim Brown K9YC wrote:

> Indeed, there is no good 
> reason for the EXISTENCE of this particular 250 Hz filter, 
> primarily because it is NOT a 250Hz filter by any reasonable 
> measure.

and Ed Muns W0YK wrote:

> Accordingly, in their application as
> roofing filters for the K3, I see no reason to have both the "250" and the
> "400" in the same receiver.