On 2/12/2013 12:22 PM, Mike Baker wrote:
Stubs can do a pretty good job but for 160M the line losses will
kill you.
NOT if you use the right coax. RG6 is a bad idea for this, but a decent
RG8 or RG213 with solid PE dielectric will kill the 2nd harmonic by 24
dB, See specific recommendations, tuning instructions, and measured
data in the Coax and Stubs Q&A, link posted a few hours ago. I haven't
measured the attenuation of 160M by a shorted 160M stub on an 80M
system, but interpolating from other measurements, I'd guess about 25 dB.
The W3NQN filters are first rate. I recently finished a survey of all
the contesting bandpass filters I could lay my hands on. Lots of
measured data and analysis, as well as reports from several major
contest clubs on reliability.
http://audiosystemsgroup.com/BandpassFilterSurvey.pdf
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