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Old March 18th 15, 02:55 PM posted to rec.radio.amateur.antenna
Jerry Stuckle Jerry Stuckle is offline
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First recorded activity by RadioBanter: Oct 2012
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Default Connecting multiple filters to multiband antenna

On 3/18/2015 6:49 AM, Brian Morrison wrote:
On Wed, 18 Mar 2015 06:44:55 -0400
Jerry Stuckle wrote:

I would not expect matching a 50 ohm antenna to a good quality filter
(which these are) would affect their response significantly enough to
cause a problem. After all, this is the exact type of operation they
are designed for.


The stop band performance is dependent on the antenna and filter
impedances out of band, at certain phases this can lead to a
re-entering stop band. I've been dealing with the consequences of this
in my day job very recently, it is a real and significant effect in
some circumstances. It's also not trivial to fix.


True. However - this was specifically made for 144/440 mhz with 50 ohm
impedance. As long as these are the bands he's using and he stays
within a reasonable range of 50 ohms, I don't see what the problem would be.

Again - these units are DESIGNED for this operation. What good would it
be to design and sell such an item if it doesn't work?

DCI has good engineers who know their stuff. Their equipment is top
quality. And while I've never tried this particular unit, I know they
would not let something with your perceived problems out the door.

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