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Ian Jackson[_2_] · July 22nd 08, 08:49 PM posted to rec.radio.amateur.antenna

In message
,
writes

Hi Frank

I am confident that you chose open ended stubs for good reason. Open
circuit stubs behave very unpredictably due to their sensitivity to their
environment. They radiate. Can you consider using longer stubs, and
making them shorted?

Yes, I considered that, however shorted stubs mean 1/2 wl at 98 MHz or
so, and they become more than 1m long, making the filter not that easy
to fit under the antenna, but who knows, maybe I'll be forced to
abandon open stubs if nothing works.

Thanks for all inputs

73
Francesco IZ8DWF

Francesco, before you go, may I ask what is the purpose of the filter?
Is it to prevent the local FM stations interfering with reception? Or is
it to stop any unexpected transmitter spurious signals from being
transmitted in the FM band?
--
Ian