Towertalk
[Top] [All Lists]

Re: [TowerTalk] Strong FM Station Impact on Antenna Analyzer Use in VHF

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Strong FM Station Impact on Antenna Analyzer Use in VHF
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Fri, 29 Jul 2016 11:08:58 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
The limitation of this approach is that any Yagi has its intended directivity only within a few percent of its design frequency. Away from that frequency its directivity is best described as "undefined." So while I agree that rotating the antenna may CHANGE the pickup from the FM station, don't expect it to change much, or in any predictable manner. :)

73, Jim K9YC

 Fri,7/29/2016 9:14 AM, Jeff DePolo wrote:
Assuming the yagi is mounted in the clear and can be rotated, first point it
at the FM station and make a measurement, and then rotate it 90 degrees
(broadside) and take another measurement.  If the apparent match/VSWR
changes as the orientation is varied, that would be a good indication that
the test instrument is being overloaded or otherwise adversely affected by
the high-level off-channel RF.


_______________________________________________



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

<Prev in Thread] Current Thread [Next in Thread>