Gain Master vs Antron99 proof at last !

[Captain Kilowatt]

Well....figure of speech... only technically correct at very low frequencies MW etc.

What I mean is point to point (as close to ground as you can get) and not via any atmospheric layers.

Don't feel bad. most people refer to any non-ionospheric communications as ground wave. I guess they think of it as being opposite of sky wave.

Conversely and something to think about...

If there is no ground wave component why does the signal diminish in strength? If it just going through space/air/ether above ground level we should be able to pick it up no problem.

The answer is simply, the inverse square law. As the distance is doubled the signal is reduced to 1/4 or 6 dB. THe radio signal is not like a laser beam. It spreads out in all directions and as a result the power density diminishes with distance.

Here is something I quote from a recent conversation with someone:"1000ft the optical line of sight is about 38miles so times that by 1.3 for radio waves because of the slight bending affect of the atmosphere on ground wave signals, say 49.5 miles so two stations each at 1000ft would have a line of sight of nearly 100miles"

Given this why do I regularly speak 100miles from a height of approx 450ft with the RX end being not much higher than myself of lower. Happens every week I am out on this hill virtually, different contacts. My "local" chat is 70miles + with ease.

There are all kinds of reasons for this. Reflections, refractions, tropospheric enhancements etc. I used to talk every morning with a station about 70 miles away. Signals would start off at nearly S-8 but drop to S-2 or less as the sun got higher. I was about 200 ft AMSL and she was basically on the seashore with a 40 foot tower. Why would the signal be so strong and then drop to mere nothing? Who knows but I am sure there was not just one factor involved.

I spoke to someone with the Gain master 120 miles away one evening this week when the band was very, very dead. I spoke to them twice, an hour in between QSO's at Signal 0 both ways, same audio quality on both QSO's. He was at 240ft ASL (using a mag mount mobile antenna) and I was at 350ft ASL. Technically that should not be possible line of sight, well over the horizon by a factor of 4.

Is it a ground wave component ?

 

[wavrider]

SO once again the term GROUND WAVE comes into the topic of discussion.

Since there is no DEFINITE answer as to why the higher freq in HF propagate similar to ground wave propagation in the early mornings.

What term is the correct one to use for this type of propagation??

 

[Heavy Metal]

SO once again the term GROUND WAVE comes into the topic of discussion.

Since there is no DEFINITE answer as to why the higher freq in HF propagate similar to ground wave propagation in the early mornings.

What term is the correct one to use for this type of propagation??

Way the neighbor down the road said and I forget we're the cut off was so ill use AM radio, ground wave is what I would hear and WBZ in Boston could hear in Florida and just after morning fog came in and was gone in morning even the longer distance listening on 12/11/10 m would be good and somewhat clean then poof gone, is this what your seeking?

Ground wave came in more so in morning with the fog, forget how he explained it to me been 40 plus years since was explained to me about it.

 

[wavrider]

Copy and paste from WIKI

Quote"Typically, what is referred to as a ground wave radio signal is made up of a number of constituent waves. If the antennas are in the line of sight then there will be a direct wave as well as a reflected signal. As the names suggest the direct signal is one that travels directly between the two antennas and is not affected by the locality. There will also be a reflected signal as the transmission will be reflected by a number of objects including the earth's surface and any hills, or large buildings that may be present. In addition to this there is a surface wave. This tends to follow the curvature of the Earth and enables coverage beyond the horizon. It is the sum of all these components that is known as the ground wave. Beyond the horizon the direct and reflected waves are blocked by the curvature of the Earth, and the signal is purely made up of the diffracted surface wave. It is for this reason that surface wave is commonly called ground wave propagation."" (End quote)

So it is surface wave for a correct nomenclature of this type of propagation???.