No Spam wrote:
I'm trying to come up with some ideas for multi-op field day station
isolation. Main problem will be front end desens between Voice and CW
portion of the same band. Main concern is on 20M

I'm thinking simple stub filters. Though they are wide, I would think
that there would be a few DB of isolation 100Khz away. Perhaps several in
parallel to narrow it up a bit.

Would a simple LC resonant circuit with perhaps 20-30Khz of BW work?

Any thing else I should be considering?


Thanks You!

I considered stubs and lumped-element filters but last year with the Machias
Radio Group, we ran two stations w/o any filters... an FT1000MP on CW and
TS430 on fone (http://www.geocities.com/bswadener/fd2007/). The tents were
separated by about 1000'. We had almost nonexistent issues with
interference.

If you want to work through design of lumped-element filters, Jim Tonne
WB6BLD (http://tonnesoftware.com/) has some nifty software available. Stubs
are covered in a book written by George Cutsogeorge W2VJN, "Managing
Interstation Interference - Coaxial Stubs and Filters", available he
http://www.qth.com/inrad/book.htm.

73 es gl,
Bryan WA7PRC