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[TowerTalk] XM240 interaction - question

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Subject: [TowerTalk] XM240 interaction - question
From: ve5sf@sk.sympatico.ca (Sam Ferris)
Date: Sat, 17 Oct 1998 22:48:20 -0700
Wonder if any CC 402cd or XM240 owners can give me some advice regarding 
interaction associated with a XM240 and a TH7 stacked about 6 feet apart 
(that's all the space I reasonably have).  Here's the situation.

Put up my new XM240 a couple of days ago - 5.25 hours on the tower 
removing the old Hygain 402 BA and pulling and assembling the XM240 up 
through a couple of other antennas.  The TH7 is mounted at 70 feet just 
above the top of the tower and the XM240 is about 6 feet above that.  The 
booms are perpendicular to each other since that is the way that I had 
the hygain 402 mounted previously to reduce SWR impacts on 15 metres on 
the TH7.  Presently the SWR on the XM240 is a little high, bottoming 
out at about 1.55 at 7.050 , 1.8 at 7.000 and 2.0 at 7.125.  I set it for 
the CW setting in the manual and followed the advice regarding the 
measurement mistakes in the manual posted by others - most helpful.  In 
comparison to the Hygain 402, it seems that impacts on the TH7 are about 
the same, the 15 metre SWR curve looks about the same as before and the 
SWR on 10 and 20 metres is now actually lower than with the previous 40 
metre antenna.

My question is if any others have similar setups with PARALLEL BOOMS, and 
if such a change to my system would reduce the impact on the XM240 by 
lowering the SWR.  Bottom line is I am not all that anxious to make many 
more trips up the tower to spin it.

In a continuing note on the new CC product, it certainly seems like a 
strudy antenna.  The alignment on the predrilled holes on mine were all 
fine except for maybe one on the boom which was relatively close.  Had to 
 trim the heat shrink as posted by others.  Mine was missing one of the 
small right angle mounting plates on the balun, (the one at the coax end 
of the balun) so I neded up using a hose clamp to secure one end of teh 
balum to the boom.  Other than that I am pleased with the structural and 
assembly aspects of the antenna.  

Any experiences or advice would certainly be appreciated.

... Sam

 VE5SF

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