[TowerTalk] CC XM240 above a big Tribander

[N2TK, Tony]

Wasn't there something said years ago about grounding the reflector on the
XM240 so it would work like the earlier 402CD? I can't remember if this was
intended to reduce the interaction on 15M or if you had the antenna at right
angles to a 20M beam the grounding would reduce a 20M resonance on the
XM240?
Lots of cobwebs in the belfry on this one.

73,
N2TK, Tony

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Bill
Parry
Sent: Wednesday, April 16, 2014 11:40 PM
To: 'Dave Hachadorian'; 'reflector Towertalk'
Subject: Re: [TowerTalk] CC XM240 above a big Tribander

Dave

I guess that it is all a matter of antennas and situations. I put up a XM240
at about 133 feet above a Force 12 C3E at 120 feet or about 13 feet apart.
The interaction between the two was fairly obvious and the SWR on 15 was not
good.  I turned the C3E 90 degrees and the problem vanished. I had the
antennas down after a lightning strike about 4 years ago and tried it again
with the same results.

Both antennas work just fine in the current configuration.  I was sure that
the 13 feet would be enough but it definitely was not.

Bill W5VX

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Dave
Hachadorian
Sent: Wednesday, April 16, 2014 8:50 PM
To: reflector Towertalk
Subject: Re: [TowerTalk] CC XM240 above a big Tribander

My XM240 is six feet above a KT-34XA.  The booms are aligned.  It works for
me.

After you get the antennas installed, run a f/b ratio test on the tribander.
Front-to-back ratio is easy to measure, and is the most sensitive test for
adverse interaction.  Here is more info:
http://lists.contesting.com/archives//html/Towertalk/2006-08/msg00634.html

I just noticed an error in the last paragraph of that 2006 posting.  The
last paragraph should read, "Sometimes just changing the length of the
40-2CD's feedline, or shorting/opening its feedline when the antenna is not
being used will solve interaction problems."

Dave Hachadorian, K6LL
Yuma, AZ

-----Original Message-----
From: Marsh Stewart
Sent: Wednesday, April 16, 2014 5:15 PM
To: towertalk at contesting.com
Subject: [TowerTalk] CC XM240 above a big Tribander

How close vertically on the same mast can a new CC XM240 be to a big
10/15/20M tribander without serious interaction?

Marsh, KA5M
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk 

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk