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Re: Where to place passband filter in signal chain?




Hi Andre,

I experienced desensing with my system in mode J and found that the problem 
was a length of coax on the 2m side.  I was able to get the problem 
corrected by putting a larger piece of coax between the antenna and preamp 
and making a small balun.  Before you go through the trouble of a passband 
filter you might just check this out.

73,

Emily


At 09:54 PM 12/8/2003 +0100, you wrote:
>Hi all,
>
>I'm experiencing some serious desense problems in mode-J.
>At the moment I'm using an FT-847 with 70cm X-Quad + SSB preamp and
>2m X-Quad + SSB preamp (pictures and schematic are on my website).
>
>I'm researching for some good designs for passband filters now.
>Two questions:
>
>- What is the best place to insert the passband filter?
>   (2m or 70cm or both? should it be between antenna and preamp or can
>    it be installed inside the shack?)
>
>- Links to good filter designs to build are welcome
>
>Thanks,
>
>
>Andre PE1OIG
>-----------------------------------------
>pe1oig at pe1oig dot net - www.pe1oig.net
>
>
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