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

[jukka.klemola at nokia.com]

Please explain stagger tuning.
Do you tune the other stub to CW and the other to SSB part
of the band, and in between a mid-band quarter wave line to
provide at least 25+dB over a broader range of frequencies?


73,
Jukka OH6LI


> -----Original Message-----
...
> W0UN -- John
...
> 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
>