[CQ-Contest] Bandpass filter

Jeff Blaine jeff at ac0c.com
Tue Jul 3 20:19:05 PDT 2012

The specific coupling is going to vary with a ton of factors.  But I am sure 
the C31 is going to be a pretty rough case.  5B4AGN measured coupling 
between the separate feed configurations and found -12db from 15 driven to 
20 receive.  Other combos had greater losses.  Bob deals with this as others 
have - a set of filters on the RX/TX side.  And stubs.


-----Original Message----- 
From: Timothy Coker
Sent: Tuesday, July 03, 2012 8:57 PM
To: Tom W8JI
Cc: cq-contest at contesting.com
Subject: Re: [CQ-Contest] Bandpass filter

I should have properly stated that the addition of a 23' open stub on the
20m line brought the measured back fed power down to less than 1 watt. I
was writing on the Droid at my work parking lot and not putting enough
thought into my previous test setup. No 15m stub used in that test setup.

I am considering the addition of 4O3A's series L high power band pass
filters for placement after my Sixpack. The line of thinking is that there
is no worry about where my stubs are placed and I can look to resell my two
sets of W3NQNs to help offset the investment. I know the cost is high, but
I believe this will help with the presence of such strong fundamental
signals with my driven elements so close on the C31XR and the 40/80/160
antennas located within 12'.

Thanks for the continued information Tom.


Tim /N6WIN.
On Jul 3, 2012 6:37 PM, "Tom W8JI" <w8ji at w8ji.com> wrote:
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