What is say is absolutely true, but in today's world it would be
possible to actually quantify some of those things.
For real time propagation it is hard to beat PSK Reporter's map of FT8
activity, assuming you have a receiver posting reports to it ... or
somebody living near you that is doing so.
As for as monitoring real time arrival angles of incoming signals, I
keep telling myself I'm going to write a browser-based application that
takes the 2-channel audio feed from a rig with two phase locked
receivers (a K3 with new synths in my case, but there are other rigs
that can do it) connected to two antennas and computes/displays the
phase difference. It's the kind of thing that is often used for
diversity reception in the horizontal plane, but it could be done with
over/under dipoles as well. It works in a browser because the relative
phase of two RF signals is preserved in the conversion to audio.
The app could also incorporate phase shifting of one signal and then
adding or subtracting it from the other to achieve directional beaming.
The volumes could be equalized just using the knobs on the rig.
I haven't done it yet, though. And it might be simpler just to buy an
SDRduo and run it using SDRuno in diversity mode. No reason that it
couldn't be done with over/under dipoles.
In all cases, a small oscillator (crystal controlled or something like
the popular Silicon Labs programmable ICs) positioned between the two
antennas could provide a reference to compensate for the phase
difference in the two feedlines.
Dave AB7E
On 1/15/2026 11:25 AM, kq2m@kq2m.com wrote:
It's sort of like ionospheric propagation - you can use VOACAP and
it's ilk, which make some simplifying assumptions (Chapman layers,
etc.) or you can just use PHARLAP (which is a full on 3D raytracing).
Or you can operate a lot and learn how propagation actually works in
real-time by observing the constant changes in path, wave-angle,
signal strength, etc. and have fun working people too!
And then, when you become a propagation master, you can start to
predict what will happen next just by listening to subtle changes in
the band noise. That's way beyond VOACAP or any propagation program
that exists.
73
Bob, KQ2M
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