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

[Jim Brown]

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.