Thanks for being such a great forum...

[TheBlaster]

this was once shared to me on this forum and I find it a great article. There are many good people here who know a lot about antennas and propagation and I found this article fascinating.

https://www.arrl.org/files/file/antplnr.pdf

I find it quite difficult to imagine radio waves bouncing of land though I thought absorption would be much more likely, bounces off of charges in atmospheric layers yes, but land ?. Are most 2,500 mile F2 layer skip hops from sea bounces, which seems much more likely as a reflective surface with less losses. They seem to think approx a 10dB loss per bounce which I imagine varies between 6 and 10dB depending on the atmospheric charge levels / absorption in the atmosphere and attenuation on earth bounces. (Other wise to traverse to the opposite side of the planet from yourself which we know is quite possible we are looking at 5 bounces @ 10dB loss in signal, per bounce 50dB. That is a big ol' attenuation.

Although I guess a +70dB signal at first incidence is quite possible as there is nothing to impede the signal from your antennas line of sight path to the first hop point.

Although one thing that helps me understand that it could bounce off land is the phenomena of moon bounce which is clearly not sea.

It sure would be interesting to see all the places that your signal bounced off of on its way to the other side of the planet. Deserts/oceans, cities etc.

 

[Handy Andy]

Excerpt from Article:

"In short, the higher the horizontal antenna, the lower is the lowest lobe of the pattern. As a very general rule of thumb, the higher an HF antenna can be placed above ground, the farther it will provide effective communications because of the resulting lower radiation angle.
This is true for any horizontal antenna over real as well as theoretically perfect ground."
​

It is a good article to remind anyone interested in CB and or Amateur.

Thanks for sharing this...

 

[Justme]

Interesting subject.

On 160 meters i have mostly no problem to work the Russian/Chinese border over 6000 miles away.
over land
The other side, USA/Canada/South America, is less as 1/2 the distance hops over sea and more difficult to do.
Every wave length has other properties as the ground/sea or sweet water lakes have,
Salt water should be a good conductor like the sea clay we have here, good for getting your radials in and far field low angle of propagation.

Many QRP ( 5 watt or less) stations still work around the world with that low power.

 

[Tallman]

I was working some stations late one night and heard my voice coming back to me and it was strong and clear. I thought someone was messing with me and playing my transmission back to me. Turns out the signal was going clear around the planet. I did not believe it at first but I checked it out and found a lot of information on the subject.
And as far as being the best, That is because of the great people that make up our corner of the internet.

 

[TheBlaster]

I have heard of that before Tallman, nice anecdote and one to listen out for : ) I had a guy where the last 1-2 seconds of his CQ call/over repeated the other day, bit weird but I never thought much of it. There is also this Spanish station whose rig cuts off the end of his over, ha ha... each and every over (cuts the last 2-3 words off) and then roger bleep for good measure just to make it even more annoying and weird.

Interesting subject.

On 160 meters i have mostly no problem to work the Russian/Chinese border over 6000 miles away.
over land
The other side, USA/Canada/South America, is less as 1/2 the distance hops over sea and more difficult to do.
Every wave length has other properties as the ground/sea or sweet water lakes have,
Salt water should be a good conductor like the sea clay we have here, good for getting your radials in and far field low angle of propagation.

Many QRP ( 5 watt or less) stations still work around the world with that low power.

I also find it interesting to think that you did not make any given contact "The one's that got away." because your antenna radiation angle/s simply skipped any given receive QTH.. i.e. your signal was 70-190 miles above the QTH on say... hop 5 or 4 or ?...... ! Or receive-able signal strength from your hops was just shy of where a stations QTH was say 300miles north, south, east.... ???? I do wonder about the footprint size of your signal as it comes down for the last time. (or maybe 2nd/3rd/4th time)

So whilst your angle of radiation was low (great you were technically perfect) you missed a great contact by pure chance. Who you did NOT speak to is as much as mysterious/miraculous as who you did !

Mind blowing really and I guess why the best antenna is one that does not have many nulls in its take off and instead goes from say 3 to 35 degrees without any big "lobal" break ups/nulls at any given angle. (In fact I have a theory about the Sirio Gain Master in this regards and why it seems to be "consistently" better than any other antenna in my practical experience.. both local and Sporadic E and F2 DX. I think Sirio might just have got the Gain Master just right in this regards. Pure coincidence can only happen so many times and when I use my Gain Master as long as there are conditions there are many and good contacts.


So when your DX sessions ends and you spoke to nobody.. you can always think.. it is because my station is too good ha ha.

On a more serious note I am quite happy with 1/2 wavelength to feed point height for Sporadic E with my vertical whereas I like closer to a full wavelength height for F2. I use only 11m.

 

[Justme]

Don't get me wrong, i worked tons of USA/Canadian and South American stations on 160, just had to do more work for it.
Looking back at the log it just works better to the east or easier, the inverted L of 77 feet high and 80 feet sloping down to 65 feet and 3000 feet of radials is doing a good job, over silty seaclay.
That inverted L is an proved design for 160 and also used through the MFJ 998 on 80/40/20.
My OCF also is resonant on 160 - 6 meters.
But being thhat low, 45 feet up not real use on 160 just quieter on receive.
For 80 - 20 the inverted L works better as the OCF after the first hop.
For Europe the OCF is the best there, so having the choise on every band beteen 2 antenna's vertical/horizontal mostly bags the goodie here.
Including the IMAX 2000 for 10/12/15/18.at 40 feet up, fed with very low loss coax, like all antenna's.

Mostly runing 800 watts from the rebuild Heathkit SB-1000 with 3-500 ZG in it, we can run max 1650 watts here.( just 3 dB more, not worth it)

Hearing back your end of transmission is seldom but happens, called Long Delayed Echo, LDE.

 

[kopcicle]

Thanks for being such a great forum...

Yeah, just wait 'till you get to know me better.

Thanks for the link

 

[kopcicle]

binrat likes this.
...and thank you for your support.

 

[binrat]

binrat likes this.
...and thank you for your support.

 

[Slowmover]

I was working some stations late one night and heard my voice coming back to me and it was strong and clear. I thought someone was messing with me and playing my transmission back to me. Turns out the signal was going clear around the planet. I did not believe it at first but I checked it out and found a lot of information on the subject.
And as far as being the best, That is because of the great people that make up our corner of the internet.

“They’s one born ever minute”
And them’s that was purpaired for yore minute, ha!

(Funny-as-hell, T-man. What were you drankin’ that night?
Little Davy’s Extract?)

.

 

[nomadradio]

First time I heard a distant station with an 'echo' was spring of 1969, operating the high-school ham club station on 15 meters. Sunspots were hot that year.

Asked the faculty moderator, the physics teacher who would be fooling around with an echo chamber on 15 meters. He pointed to the heading on the 6-element beam, pointing directly away from the guy in California with the 'echo'. We were hearing his direct (short path) signal off the back of the beam, and the long path the other way around from the front. Turned the beam towards him and it went away.

The long-path delay is under a full second, just don't remember exactly how much. Depends on "how long", pretty sure.

73

 

[Tallman]

“They’s one born ever minute”
And them’s that was purpaired for yore minute, ha!

(Funny-as-hell, T-man. What were you drankin’ that night?
Little Davy’s Extract?)

.

I could reply with something pithy and low brow. Do some research and find out for yourself. You need some assistance in the science department. No drinking or smoking.
If we can bounce signals off of the moon at 238900 miles why not off of the "E" layers in our atmosphere? That would be less 25,000 miles.Far less preposterous than some of the CB claims I have heard..

 

[Tallman]

First time I heard a distant station with an 'echo' was spring of 1969, operating the high-school ham club station on 15 meters. Sunspots were hot that year.

Asked the faculty moderator, the physics teacher who would be fooling around with an echo chamber on 15 meters. He pointed to the heading on the 6-element beam, pointing directly away from the guy in California with the 'echo'. We were hearing his direct (short path) signal off the back of the beam, and the long path the other way around from the front. Turned the beam towards him and it went away.

The long-path delay is under a full second, just don't remember exactly how much. Depends on "how long", pretty sure.

73

Solid and the truth.

 

[Justme]

Long Delayed Eacho's are for real, in fact already in 1927 they did serious investigations in it.
http://folk.uio.no/sverre/LDE/

 

[TheBlaster]

With current Sunspot minima (although we have had 2 very small ones in as many weeks ) it is unlikely this guys end of sentence I heard delay would be this phenomena on 11m. There does seem to be some skip that I largely cannot RX with my omni but I do hear European stations calling outside Europe, must be super weak F2 layer stuff only a beam user can work. I have heard feint USA voices on the relevant frequencies on 11m, but did hear a station calling W.Indies and Caribbean last night so there might be a very small amount of long haul out there.

I feel rather like naughty boy having started this up on the Amateur forum, it's just I know the antenna experts hang out on here

This seems to be the most technical of the radio forums and by no means do I know it all, I just think about things and have a semi educated guess, I do read ham books over here and like articles and this forum, it is my maths that lets me down a bit.

No doubt I will be highly envious you guys are working global stations on your active lower frequency bands come winter when the summer Sporadic E skip dies off .