[Elecraft] Band pass filters, was ICE

[Alan Bloom]

It is much harder to design a bandpass filter narrow enough to pass the
CW portion of a band while blocking the phone band or vice versa.  But
it is not impossible.  Several decades ago the Murphy's Marauders
contest club had some giant helical resonators that could do the job.
As I recall the 20 meter one was the size of a rural mailbox.  It had a
knob so you could tune it to frequency.

Al N1AL


On Thu, 2011-04-28 at 12:24 -0700, Jim Brown wrote:
> Bandpass filters are just that -- they PASS the 
> entire ham band, and only STOP signals outside the band.  They will have 
> NO effect on phase noise produced by a transmitter on th SAME band. A 
> MUCH narrower filter is needed.