groundwave talking?

[222DBFL]

I have talked consistently now out to 70 miles with my NV4K and 50 watts max power. Antenna is 26ft to the base. I've also talked all the way across the state as well. From Daytona Bch. area to Crystal River. The other contact that is 70 miles is direct south 70 miles in Cocoa Beach. Not sure what either of these guys run for antennas but I do know elevation is about the same minus the hills I have to cross around the Lakeland area. But that is across the state. Again 70 miles is confirmed. No issues talking that far as long as the conditions aren't totally shut down!!

 

[RatsoW8]

So, if I found the correct formula for determining actual service range for line of sight propagation this is a good way to estimate for perfectly flat land. So, I can see how longer distance contacts by line of sight can happen if you're station in located on the coast and have relatively flat terrain between you and the other station. The range can be more if you take into consideration the other stations radio horizon.

for h in meters and d in kilometres

So, then my iMay2K at 35 feet would have a line of sight radio horizon of about 9 miles if our terrain was fairly flat. Sounds about right to me so, a station with an antenna at the same height could be 18 miles away and we should be able to make a contact. Sound about right?

 

[BBB]

Best local conditions for me at 300' elevation are in the wintertime with all the leaves off the trees, a ground cover of at least 3" of snow and a layer of ice on top of that. Foggier the atmosphere the better.

Not sure of all the science behind it, just know I can get out about 75 miles with those conditions present.

 

[Captain Kilowatt]

So, if I found the correct formula for determining actual service range for line of sight propagation this is a good way to estimate for perfectly flat land. So, I can see how longer distance contacts by line of sight can happen if you're station in located on the coast and have relatively flat terrain between you and the other station. The range can be more if you take into consideration the other stations radio horizon.

for h in meters and d in kilometres

So, then my iMay2K at 35 feet would have a line of sight radio horizon of about 9 miles if our terrain was fairly flat. Sounds about right to me so, a station with an antenna at the same height could be 18 miles away and we should be able to make a contact. Sound about right?

The radio horizon is generally accepted to be 4/3 of the optical horizon or in other words about 1/3 further than you can see however this is for VHF and above. HF temds to be even further. I have yet to see a formula that accurately determines true working distances. Take-off angle, power output, and even frequency to an extent all factor into distance.

 

[Road Squawker]

Best local conditions for me...at least 3" of snow and a layer of ice on top of that. Foggier the atmosphere the better....

Perhaps thats because more people are inside were it is warm and playin radio

 

[Bearcat]

Best local conditions for me at 300' elevation are in the wintertime with all the leaves off the trees, a ground cover of at least 3" of snow and a layer of ice on top of that. Foggier the atmosphere the better.

Not sure of all the science behind it, just know I can get out about 75 miles with those conditions present.

What's your antenna?

 

[Tallman]

12,450.5 miles plus a foot or so............. MAX distance

That is 1/2 way around the earth. I was at a friends house and he was talking to this operator on the other side of the planet. Conditions started to fade a little bit and he told the operator to stand by while he rotated his antenna 180 degrees. I thought he must have gone nuts for sure. When it got to the 180 degree mark he keyed up and the signal was stronger. It seems the propagation favored going the slightly longer distance. It still seems incredible to me that turning your beam antenna and pointing in the other direction would work. It did and I'm scraping up the money to buy an antenna system just like his.

 

[Bearcat]

That is 1/2 way around the earth. I was at a friends house and he was talking to this operator on the other side of the planet. Conditions started to fade a little bit and he told the operator to stand by while he rotated his antenna 180 degrees. I thought he must have gone nuts for sure. When it got to the 180 degree mark he keyed up and the signal was stronger. It seems the propagation favored going the slightly longer distance. It still seems incredible to me that turning your beam antenna and pointing in the other direction would work. It did and I'm scraping up the money to buy an antenna system just like his.

What beams was he running?

 

[Captain Kilowatt]

That is 1/2 way around the earth. I was at a friends house and he was talking to this operator on the other side of the planet. Conditions started to fade a little bit and he told the operator to stand by while he rotated his antenna 180 degrees. I thought he must have gone nuts for sure. When it got to the 180 degree mark he keyed up and the signal was stronger. It seems the propagation favored going the slightly longer distance. It still seems incredible to me that turning your beam antenna and pointing in the other direction would work. It did and I'm scraping up the money to buy an antenna system just like his.

It's called longpath. I worked 3B9C on Rodriguez Island off east Africa from my mobile via longpath one morning. He was calling "CQ North America via longpath". 15,000 miles from the mobile with 100 watts on 20m. The short path was non-existent at the time.

 

[Tallman]

Hy-Gain brand, don't know all of the particulars.
The thing looks like a Boeing 747 on his antenna mast.

Hy-Gain TH-4JRS - Tri-Band HF 4 Element Beam Antenna
He modified it to add another band as well

 

[Captain Kilowatt]

Best local conditions for me at 300' elevation are in the wintertime with all the leaves off the trees, a ground cover of at least 3" of snow and a layer of ice on top of that. Foggier the atmosphere the better.

Not sure of all the science behind it, just know I can get out about 75 miles with those conditions present.

About the only science behind it is that local noise levels tend to be lower in winter as well as lower storm static crashes.

 

[Needle Bender]

So, if I found the correct formula for determining actual service range for line of sight propagation this is a good way to estimate for perfectly flat land. So, I can see how longer distance contacts by line of sight can happen if you're station in located on the coast and have relatively flat terrain between you and the other station. The range can be more if you take into consideration the other stations radio horizon.

for h in meters and d in kilometres

So, then my iMay2K at 35 feet would have a line of sight radio horizon of about 9 miles if our terrain was fairly flat. Sounds about right to me so, a station with an antenna at the same height could be 18 miles away and we should be able to make a contact. Sound about right?

That would be an interesting test. If 2 stations set up on flat ground, no hills or ridges between them, I wonder how far apart they could QSO with only 12w pep and their antenna base right at 1wl above ground using a couple A99s then 5/8?
Then try it over water.

 

[wavrider]

That would be an interesting test. If 2 stations set up on flat ground, no hills or ridges between them, I wonder how far apart they could QSO with only 12w pep and their antenna base right at 1wl above ground using a couple A99s then 5/8?
Then try it over water.

NB I have talked from my QTH to Crescent city FL about a 60 mile distance as the crow fly's.

It was very quiet that evening light rain and his antenna was 15 foot AGL mine was 55' AGL both of us running 12 watts PEP. AM mode and I was using homebrew 5/8 wl gp he was on an I2K.

Don't happen often but when the conditions are right and the band is quiet

 

[Needle Bender]

NB I have talked from my QTH to Crescent city FL about a 60 mile distance as the crow fly's.

It was very quiet that evening light rain and his antenna was 15 foot AGL mine was 55' AGL both of us running 12 watts PEP. AM mode and I was using homebrew 5/8 wl gp he was on an I2K.

Don't happen often but when the conditions are right and the band is quiet

OK, let's see, 15+55=70÷2 = an average height of 35', pretty close!

I wonder, if that was a rarity, then why? Satellite? Thermal inversion? So what distance seems consistent, or was that just a rare night in terms of how quiet?

 

[RadioDaze2.0]

Best local conditions for me at 300' elevation are in the wintertime with all the leaves off the trees, a ground cover of at least 3" of snow and a layer of ice on top of that. Foggier the atmosphere the better.

Not sure of all the science behind it, just know I can get out about 75 miles with those conditions present.

I have noted that foggy conditions seem to correlate with longer distances. I cannot understand the mechanism. It may be that there is greater likely hood of fog when tropospheric conditions are good.

There is an upcoming radio night here in the UK and it looks set to be good as this map demonstrates so I expect to be hitting 150-200 miles distances.

http://www.dxinfocentre.com/tropo_nwe.html

I have however noticed that much like the normal weather forecast it evolves over time