Basic Big Beam Question

[wavrider]

Good post Henry.

Ground wave?

I have read where there is no such thing as "ground wave" on the upper HF frequencies. Yet I have talked "ground wave" many times when conditions were right.

This is just my opinion but I believe there is not a correct phrase yet established for the phenomenon we call ground wave on the upper HF freq's..

It is not direct wave as the distance is to far. Not line of sight. Yet when the conditions are there it is possible to make contacts 100 miles or more in distance.

It is almost like thermo ducting on VHF, but not quite like that.

I have also read where vertical is better for ground wave contacts. which may be the case on the lower HF frequencies. I (as some have already posted) have talked ground wave horizontally polarized off of a two element quad.

So in my way of thinking there is not a term that is phrased for the "ground wave" propagation that is experienced on the upper HF freq's, thus some ops will say no such thing as ground wave on the upper HF freq's.

 

[hookedon6]

...

I have read where there is no such thing as "ground wave" on the upper HF frequencies. Yet I have talked "ground wave" many times when conditions were right.

This is just my opinion but I believe there is not a correct phrase yet established for the phenomenon we call ground wave on the upper HF freq's..

It is not direct wave as the distance is to far. Not line of sight. Yet when the conditions are there it is possible to make contacts 100 miles or more in distance.

It is almost like thermo ducting on VHF, but not quite like that..

what a lot of people call ground wave on the high bands is really Es.

 

[hookedon6]

The above is by the way based on "behaviour of shortwave signals from H. Molhuizen".

But im also perfectly aware that bookes can be wrong, or the interpertation of the reader is not rigth...

Terman's Radio Engineer's Handbook (1943) is a great reference on this subject

 

[HomerBB]

I don't usually bother with discussions on something like this - ground wave yes/no.
The reason is simple:

" A person with an experience is never the servant to one with an argument"

I have already proven to my satisfaction one or two things along the way that I don't have to accept anyone's arguments for or against. I do enjoy dissecting information to learn, but have no use for outright denial of empirical evidence. Explanations of why/what are better. Talking beyond line-of-sight happens frequently, and when you live where I do it is rare enough to be remarkable.

This is one debate that goes 'round and 'round, yet as it is experienced someone looks for a new name that won't change anything.

Calling it mayonnaise won't turn peanut butter into mayonnaise.

Until someone does a better job of defining the debate no matter how much I respect the opposing constituents of the discussion(?), I just don't accept anything except what ever it is it is happening.

So, when the ARRL handbook says that this phenomenon is officially "talking a long long way when no skip is in" remember Homer said it first right here on WWRF.

 

[Henry HPSD]

It would be rather difficult to work a station say a.. 100 miles away through sproadic E.
The best i have done (for short range sproadic E) was around 400 Km

Anyway....
I already got a reply from the "propagation guy".
He replied in Dutch, so my appologise for not making great lines (im trying to keep it as close to the original as i can, but youll get the point).

Anyway...here goes:

The "term" groundwave is used if the wave hasnt reached the ionosphere..you are correct on that.

The ground wave can be calculated using this forumula 200/extract the root of the frequency.
For 28 Mhz this would be: 200/5,29 = 37,8 Km
(source K.G.Budden.Kenned Davis-university of cambridge.

The energie that remains, depends on the take off angle of the antenne.
It is a bit short to say that a vertical would be better.

The "dying" of a groundwave is due to the propagation run-time difference beteween ground and air. (the beverage antenna takes advantege of this).

The waves fall over each other at a certain point which is why the field vanishes on its own. (anti fase etc)

There is no difference between the different fields.

END OF QUOTE.

My graditude goes to Norbert for providing the above.

I have asked confirmation towards him in aspect of a favoured polarisation for ground wave communication.

The way i read his email i notice he says there isnt any bennefit using either.

I hope it is of use.

Kind regards,

henry HPSD
19sd348

 

[hookedon6]

It would be rather difficult to work a station say a.. 100 miles away through sproadic E.

The ground wave can be calculated using this forumula 200/extract the root of the frequency.
For 28 Mhz this would be: 200/5,29 = 37,8 Km
(source K.G.Budden.Kenned Davis-university of cambridge.

well, here in FL,.... surrounded on 3 sides by SALTwater, I can tell you that E-skip goes further than 100 miles


Communication distances of 800–2200 km can occur using a single Es cloud. This variability in distance depends on a number of factors, including cloud height and density. MUF also varies widely, but most commonly falls in the 27–110 MHz range,

Mid-Latitude Sporadic-E (Es) - A Review look at figure two, this is for a SINGLE hop, there are often multi hops Es.

granted, multi hop and distances greater than approx 2100 Km occur at higher freqs than 27 Mhz, but, single hop 27 Mhz Es does occur with coms out to 2100 Km.



the 37.8 Km is about right,.... heck the ground wave on 160 stops at about 40 miles.

 

[Henry HPSD]

pse read my post again.

You were refering to that some people migth mistake sproadic e for groundwave.

In my mind that seems a bit strange..most people notice the difference between actually sproadic-e skip (upto several thousands of kilometers) and a qso 100 miles away.

Therefor I said it is difficult to get sproadic e upto about 100 miles
The closest i have ever managed was about 400 km, in reference to the
(short distance sproadic-e, as mentioned!)

It was just to show you sproadic e happens often futher away as you are telling some migth think in your reply.
It was to show i never had anyone telling me a qso over 100 miles was through sproadic e.

Hope this clears it up a bit.

Kind regards,

Henry

 

[hookedon6]

pse read my post again..

Kind regards,

Henry

agreed

I guess you can tell that I do a lot of 6 meter and above Es.

... and when the muf gets to about 28 Mhz it can also be a lot of fun

 

[Mr Clean]

ok,................. I start it

there is no "ground wave"propagation on 11 metersop:op:

OK surface wave. Is that OK The ground around me is fairly flat and if you feel the surface of a globe that shows elevations for mountains the globe is really flat over southern indiana and nearby parts of ky and IL. We can talk some real nice distances on surface wave. Me and daddy long legs in Lexington KY talk 170 plus miles on AM. And we have done so on any occasion we tried to. Sometimes with better signals than others. I cant prove flat is better for surface wave but its been my experience. I was under the impression that with soradic e conditions alot of times your beam will not be pointed at the station you are hearing. Daddy long legs is east of me and I have heard him when pointed west talking toward cali when talking out to the westcoast. Turn and point at his station and he is gone. Maybe the reason I have had better luck at distance talking on the flat is that more people use vertical antennas and the fact that other signals dont interfere with the long distance surface wave contacts on horz as much and it is quieter Peace

 

[hookedon6]

. Daddy long legs is east of me and I have heard him when pointed west talking toward cali when talking out to the westcoast. Turn and point at his station and he is gone.

sounds like backscatter

 

[Mr Clean]

sounds like backscatter

Yes I think your right. Ive been up to long:blushing: