[CQ-Contest] Bandpass filters for M/S or M/M environment

[W0UN -- John Brosnahan]

At 09:05 AM 6/11/2004, R. Kline wrote:

>I agree in principle. However the 30-40 dB attenuation expected appears
>somehwhat exaggerated from my personal experience and from what I've read.
>Perhaps there is a more involved system of stubs that will do this (other
>than a simple short circuited quarter wave stub in parallel with the
>line)?????
>73
>Riki   K7NJ - 4X4NJ

30 + dB is easily obtainable at the deepest part of the null with a single
filter.  But the Q is fairly high.

40 + dB is easily obtainable with the typical dual-stub filter.  With proper
stagger tuning it is possible to maintain 40 dB over a broader range.
I always use twin stubs--1/4 wave apart on the harmonic to get a solid
30 + dB over most of the band/mode.

I can't provide specific patterns--my notes are all at the Colorado QTH.

--John
-------------- next part --------------

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.675 / Virus Database: 437 - Release Date: 5/2/2004