Topband: Monopole Radiation Patterns, takeoff angles etc

[Mike Waters]

Let me expand on what I said previously.

I always thought that ground wave propagation decreased with frequency. For
example, don't AM broadcast stations in the lower end of the AM broadcast
band have greater coverage than at the high end, all things being equal? I
have always thought that, and I also think that this phenomenon increases
as we move through 160 meters, then through 80, 40, etc. etc. and we become
more and more dependent on higher angles there for at but local
communications.

Of course, this is somewhat dependent on the time of day, whether we are
talking about daytime or nighttime propagation.

Before my 1/4 wave 40 meter ground plane (elevated radials) came down last
year, I repeatedly tried to make contact with KD0APS during the day, about
60 miles away with 100 watts. I also could barely hear him on any Beverage
antenna on any band. Even feeding 800 watts into that antenna, he had
difficulty copying me through his high ambient noise level. Only after I
put up my dipole were we able to have a QSO, and signals were FAR stronger
at each end, even with both of us using 100 watts. This was during the day,
every time.

This is by no means the only time I have experienced this.

In the past, I have done many, many experiments --with different antennas--
on many different ham bands from 80 through 10 meters seeing which bands
were better for the people I used to regularly talk to, most of which were
in Ohio (where I lived) and surrounding states. Most (but not all) of this
was done after dark. As we went up in frequency, the path loss got worse
even thought the noise greatly decreased. I even had a 1/2 wave ground
plane with elevated radials for 20 meters, and a 5/8 wave elevated ground
plane for 10 meters, and so did some other stations I was communicating (or
attempting to communicate) with.

What I am saying is that ground loss must increase the higher we go in
frequency, attenuating the surface wave more and more the higher and higher
we go.

Maybe there's another explanation for these observations?

I am just trying to wrap my brain around what Richard Fry is trying to tell
us here. I have a lot of respect for him, and I've learned a lot from him.
But something is just not sinking in here.

73, Mike
www.w0btu.com