On 1/17/2026 1:53 PM, Steve Dyer W1SRD via TowerTalk wrote:
Isn't a quarter wave vertical with a counterpoise just a bent dipole?
Remember the CrankIR?
It's all a "way of looking" at the problem. The late Richard C. Heyser,
the engineer whose day gig was space communications at JPL, and who
revolutionized the acoustics of sound systems both with his invention of
Time Delay Spectrometry and his teaching to a generation of us working
in the field, taught us the usefulness of multiple "ways of looking" at
the same problem.
One was using the inverse FFT of a sweep of amplitude vs frequency to
study the time response of a system. This allowed us to study
reflections in an auditorium or worship space that were making speech
intelligibility difficult. It's also the method that many VNAs use for
TDR. DG8SAQ's software for his VNWA that SDRKits in the UK uses this
method, and provides multiple dozen window functions for it.
Over the years, I've learned a lot by looking at problems in a different
way. Plotting data from multiple NEC plots for horizontal antennas at
varying heights designs (in the second link I posted) is an example.
73, Jim K9YC
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