On 11/2/21 11:41 AM, Mpridesti via TowerTalk wrote:
My 80 m 4 SQ seems to work well in 3 positions. To the SW the signal drop in
the favored direction where the other 3 directions appear to work well.
SWR measurements seem normal around 2:1 at the end of the 1/4 wave 75 ohm lines except
one which is 1.87. Haven’t made loss measurements yet but I suspect the lowest
SWR line is the problem (low reading due to higher than normal loss making it the
suspect line).
Has anyone else experienced this type of behavior? Also the suspect line is the NW element
and the direction which has the problem is SW. Does this make sense? Effectively this lossy
element is the other half of the “driven element “ if you thought of the 4 sq
as a 3 el vertical beam.
Keeping with this concept, one would think the NE direction would have similar loss but it
doesn’t (or it’s not noticeable).
This is where a NanoVNA might be a useful tool. Not only can you go out
to the box and measure each element separately, but you could measure
the element to element coupling, and I'll bet you'd see something.
You *might* be able to do a sweep from the shack, through the box, and
figure something out too, but figuring out which of the 4 has a problem
- I guess you could switch the direction of the beam and probably figure
it out.
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