Dana Roode wrote:
>
> I've seen lots of discussion about K3 filters so here's my question.
> I've got the 400 hz 8 pole filter and it works well. During the ARRL
> 160 contest I had trouble "running" due to someone else doing so about
> 300 hz up the band. I was thinking about acquiring either the 250 8
> pole or the 200 5 pole. Any thoughts? I have not seen any data on
> the 200 hz filter, but the 250 seems more like a 370 hz filter if you
> look at the filter plot. Which do I want?
>
Probably the 200 Hz. You're correct about the "250" which is only ~65 Hz
narrower than the 400 (which is actually ~435 Hz if my memory is correct).
My 200 measures ~205 Hz at the 6 dB points so you would notice more of a
difference with it even though it has wider shoulders (i.e. 5-pole instead
of 8-pole).
I have both a 500 and 200 and use both on 160. Normally I prefer the 500
but there are times when the 200 is very nice to have...such as in a large
nearly simplex DX pileup with lots of strong stations calling. I would
normally not want to use the 200 in a contest, because I would miss the guys
calling off-frequency, but it's nice to have it available when necessary.
Someone else asked about the filter plots on the Elecraft and Inrad
websites. I believe all of these were made by George W2VJN before he sold
Inrad to N5KO and AG9A. I hope Elecraft or Inrad might ask George to graph
the missing filters (all 5-pole and some 8-pole) eventually (including the
yet to be introduced variable bandwidth filters). If George cannot do it
perhaps Jack K8ZOA could do this.
73, Bill W4ZV
--
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Sent from the Elecraft mailing list archive at Nabble.com.
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