The other "easy" approach is to use a BCB high pass or band reject
filter on the output of the FA-VA5 and "calibrate it out." That is
run the OSL calibration on the cable coming out of the highpass/band
reject filter. One can do that with any VNWA that allows calibrating
at a "remote plane".
One might not want to juggle the VNWA and filter at the top of a
tower, but it is not a difficult issue at the base of a vertical.
73,
... Joe, W4TV
On 2018-11-30 12:49 PM, Wes Stewart wrote:
By two-port version I think you mean the SDR-Kits VNWA (DG8SAQ); the
FA-VA5 (https://www.youtube.com/watch?v=X8Z7veGV57o) is an entirely
different animal by a different designer (both Germans however).
I have both, the VNWA for a year or two and the FA-VA5 for a couple of
months. I also have an original N2PK, the guy that started these things,
a Rig Expert AA-55 Zoom and just leaving US Customs, an FAA-450 by EU1KY.
I also have a 50KW BC station on 1550 kHz, about 5 miles away. On my
inverted-L they are S9+70dB (~-3dBm) on my calibrated K3/SDR-IQ combo.
I can use any of these instruments to measure the antenna without issue
as long as I avoid sweeping through the BC band.
Wes N7WS
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