Topband: Monopole Radiation Patterns, takeoff angles etc

[Hardy Landskov]

----- Original Message ----- 
From: "Mike Waters" <mikewate at gmail.com>
To: "topband" <topband at contesting.com>
Cc: "ZR" <zr at jeremy.mv.com>; "Richard Fry" <rfry at adams.net>
Sent: Monday, May 07, 2012 7:35 PM
Subject: Re: Topband: Monopole Radiation Patterns, takeoff angles etc


> 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?

Yes most definately. Ground wave is substantial over sea water. Why do you 
think
the international distress frequency for ships was at 500 KHz?

> 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.

What you say is about lowering frequency is true. This is why submarines can
communicate throughout the World because at low enough frequencies, the 
whole
planet Earth looks like an insulator.

73 Hardy N7RT