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groundwave talking?
- Thread starter Bearcat
- Start date
If you're operating much above 3 MHz, there IS no "ground wave", and since true ground wave is vertically polarized, a horizontal antenna won't help much. You probably mean "sky wave", which follows the surface of the earth a bit beyond the visible horizon.
Hi there a few factors dictate your performance in this regards. It is as much to do with the RX end as your station.
I tend to call thess line of sight contacts or point to point. As someone mentioned really ground wave is a type of RF prop that only exists at much lower frequencies. It allows your signal to propagate way beyond the horizon.
1) Height above ground level of your antenna.
2) Height above surrounding average terrain i.e. height above absolute sea level of your station set up.
3) RX station antenna and radio and their height above sea level.
4) Your RX noise floor and the RX stations noise floor.
5) Power output
6) Quality of your vertical antenna.
7) Modulation mode, SSB tends to work best for long distances.
Then issues like the quality of your coax, connectors, VSWR all have a small part to play.
Occasionally you will get 100-200 miles with ease with a tropospheric ducting lift. But without any lifts typically I manage the following....
I can speak to someone 30 miles or so away with 0.25 Watts on SSB. They have a great RX though.
At around 400 - 550ft ASL with no lifts I talk 70 miles all round with ease. (favouring some directions) 90 miles with regularity and 130+ miles fairly frequently. 150 miles occasionally. 170miles is possible with non tropo conditions with a person at 1,500ft ASL (even when they are using a Sirio 4000 mag mount lol) And my record line of sight of 240 miles with RX station mobile static at height as well.
I tend to call thess line of sight contacts or point to point. As someone mentioned really ground wave is a type of RF prop that only exists at much lower frequencies. It allows your signal to propagate way beyond the horizon.
1) Height above ground level of your antenna.
2) Height above surrounding average terrain i.e. height above absolute sea level of your station set up.
3) RX station antenna and radio and their height above sea level.
4) Your RX noise floor and the RX stations noise floor.
5) Power output
6) Quality of your vertical antenna.
7) Modulation mode, SSB tends to work best for long distances.
Then issues like the quality of your coax, connectors, VSWR all have a small part to play.
Occasionally you will get 100-200 miles with ease with a tropospheric ducting lift. But without any lifts typically I manage the following....
I can speak to someone 30 miles or so away with 0.25 Watts on SSB. They have a great RX though.
At around 400 - 550ft ASL with no lifts I talk 70 miles all round with ease. (favouring some directions) 90 miles with regularity and 130+ miles fairly frequently. 150 miles occasionally. 170miles is possible with non tropo conditions with a person at 1,500ft ASL (even when they are using a Sirio 4000 mag mount lol) And my record line of sight of 240 miles with RX station mobile static at height as well.
Could be anything from 40-80 miles. These things are not easy to nail down as they are very dependent on all the above factors.
12,450.5 miles plus a foot or so............. MAX distance
In that range you can always find some body to talk to. I like having multiple bands to talk on. Seems like skip is always on somewhere.
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
Sounds reasonable and definitely in tune with the thread. I'm going back to re-read everything about propagation
Sounds reasonable and definitely in tune with the thread. I'm going back to re-read everything about propagation
Me too!
With Imax I can talk 50 miles local consistenly to a specific station. Most stations local about 30 miles is the range.
When we get the rare local skip conditions it's usually in the 300-500 mile range.
And your normal everyday type skip usually starts at 1,000 miles and moves further out to whatever.