Thanks all for your great answers! There was indeed no ground, so stupid me
:) One of the antennas was a groundplane antenna, and I would have
expected somewhat better behaviour there. It was for 2m and I was still
fairly close by. I will try again with the antenna on a small mast about 3m
off ground.
Am Sa., 22. Aug. 2020 um 07:00 Uhr schrieb alan victor <
avictor73@...>:
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I should add, if the physical size of the vna is comparable to the
physical size of the antenna under test, the affect of the vna is
significant. On the other hand, for example, I measured a 40 meter dipole
10 feet above ground. It was ~ 67 feet in length and flat. An NVIS antenna.
The vna was clipped onto the dipole center arm and the affect of holding it
is nil. The resonance of the antenna was obvious as well the swr spot on.
Since I was standing at the antenna I was in the near field. However, at 6
Foot 7... I am physically small compared to 67 feet!
Alan
