Natan writes:
> Why not convince Steve and Ward to resurrect their toys and do
> a 2nd generation comparison of antennas using the C31XR and the
> SteppIr. At least you would have a standard to compare forward
> gain, f/b and possibly other parameters too.
It is relatively easy to do that comparison for yourself if you
already have the second edition of the K7LXC/N0AX "Tribander Test
Report." The K7LXC/N0AX report includes all of the raw data for
both the C31XR and the C3. Field test data for the two and three
element SteppIR at www.steppir.com/pdf/gain%20fb%20brochure.pdf
was taken using the K7LXC/N0AX protocols (dipole comparison at
48').
The two sets should be directly comparable; the protocols were
designed to allow multiple tests and multiple locations to be
compared directly without the need to test all antennas at all
locations.
I've also done model comparisons of the SteppIR and Force12
antennas which correlate well with the two sets of field test
results and Force12's claimed gain and F/B numbers
The SteppIR 4 element yagi vs. Force 12 C-31XR at 74' above
flat ground (gain in dBi):
C-31XR SteppIR elev.
Band Gain F/R Gain F/R
20 14.0 20 15.0 20 13 degrees
17 n/a 15.7 22 10 degrees
15 14.3 22 16.1 22 8 degrees
12 n/a 16.2 22 7 degrees
10 15.6 21 16.6 11 7 degrees
6 n/a 18.7 20 4 degrees
The C-31XR numbers are Force-12 published specifications and
confirmed by modeling with AO. The SteppIR numbers are from
modeling in AO/YO (6 meter values include the optional passive
elements).
The SteppIR 3 element yagi vs. Force 12 XR-5 at 74' above
flat ground (gain in dBi).
XR-5 SteppIR elev.
Band Gain F/R Gain F/R
20 12.6 16 13.4 20 13 degrees
17 12.6 16 13.8 21 10 degrees
15 12.8 17 14.2 21 8 degrees
12 12.6 20 14.8 14.5 7 degrees
10 12.5 21 15.2 11 7 degrees
6 n/a 16.0 20 4 degrees
The XR-5 numbers are Force-12 published specifications *NOT*
confirmed by modeling with AO. The SteppIR numbers are from
modeling in AO/YO (6 meter values include the optional passive
element).
73,
... Joe, W4TV
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