FURTHEST LOCAL NON-DX CONTACT?

[TheBlaster]

If by non dx you mean not refracted from E or F2 layer then...

11m band (this is cb forum so longer wavelengths surely don't apply) 240 miles hill to hill... probably a slight tropo enhancement, although with the struggle we had to share the most basic information would suggest there was not much of an enhancement. S0- R 1-2 copy both way.

With a tropospheric ducting lift you can do immense distance line of sight with surprising signals at each end - ground wave (not really ground wave prop for 11m but you know what I mean) So one day you may be giving someone an S4 - S6 200 miles away (hill to hill) but this won't happen the next day with no lift on, worth bearing that in mind. Chances are you won't even hear each other the next day.

https://www.amateur-radio-wiki.net/tropospheric-ducting/

I know someone whose signal has gone 250 miles on 11m on this forum and they are not on a hill either.... I know for a fact cause I heard him, it was not a skip contact either and he is not even in the same country as me !

It takes 2 high performance stations to make such long point to point contacts, especially with just vertical omni's at the each end. Horizontal beam to beam and you can extend this range even further (lower noise, large forward gain x2 (at each end) and directionality)

 

[Justme]

Yep, that was fun, pitty conditions were'nt there that day, better luck next time
To be honest, i Was running 700 watts into the Imax 2000 at that time, but from 2 meter below sea level where the ground is....

 

[Christophe Barbe]

My take on the longest contact on CB without any help like: skip from ionosphere, tropo and any temperature related wave refraction back to Earth, elevated antenna system (on a hill) could be no more than 50 miles due to the curve of the Earth.
Longer distances are due to the above "helping factors".
This with more than the legal 12W and a gain antenna at reasonable height above ground level.
Top of that it means terrain may not be hilly but rather flat and not through a city but in the country side.
Longest distance report I have had was from a truck driver hearing me 80mi from home on 2m, but I had 2x11 element yagis and 170W, on 2m band FM.
73, Chris 14AT733, 109PAT733, KP733, HA7WX

 

[radioreddz]

With my 4 square array 4 IMAX 2000’s 18’ to the feed points off the ground and 100 Watts pep on SSB I regularly talk to a guy 105 Miles as the crow flies and have talked 140 miles as the crow flies.c

 

[Christophe Barbe]

With my 4 square array 4 IMAX 2000’s 18’ to the feed points off the ground and 100 Watts pep on SSB I regularly talk to a guy 105 Miles as the crow flies and have talked 140 miles as the crow flies.c

You sure have some terrain specificities in the path as fewer obstacles or some water area, maybe also helped by temperature inversion ducting.
100 mi is a LOT, taken into account the Earth curvature as upper HF, ie. 27mhz does not behave as long wave frequencies where there's ability to follow Earth curvature.

 

[radioreddz]

You sure have some terrain specificities in the path as fewer obstacles or some water area, maybe also helped by temperature inversion ducting.
100 mi is a LOT, taken into account the Earth curvature as upper HF, ie. 27mhz does not behave as long wave frequencies where there's ability to follow Earth curvature.

Those contacts are in my best direction to talk I talk nightly from my location in So.Md. To Staunton VA 105 miles Petersburg VA 100 Miles regularly even have talks when its really good conditions early mornings into Lake Gaston NC. 143 Miles all on 38 LSB with 100 Watts pep. But North I struggle to talk 70 miles

 

[TheBlaster]

You sure have some terrain specificities in the path as fewer obstacles or some water area, maybe also helped by temperature inversion ducting.
100 mi is a LOT, taken into account the Earth curvature as upper HF, ie. 27mhz does not behave as long wave frequencies where there's ability to follow Earth curvature.

Your initial theory is pretty much what the books says.. however in reality with a very good antenna at both ends, some power, very low noise floor QTH, quality feeders good RX in the radio and height 100 mile contacts are common. I am fairly sure I speak to someone every time I go out at 100 miles distance. It is not an exception it is pretty much normal. Height clearly extends the RF horizon and 11m wavelengths seemingly fair a little better than VHF signals over such distances, given at 11m they are often "omni vertical" propogated signals. With height and the above technicalities taken care of at both ends you don't need much lift at all to speak 100-150 miles.

Clearly these contacts may have a luck element meaning there is a lift on at that moment so the S0 R5 contacts are made over such distances. And they can drop off to a hiss and no copy after 10mins or 20 or....????

There is always some degree of "conditions" but it is whether the stations can work them or not... and why every little you can improve your station counts.

As mentioned (despite it being only once) I heard someone clearly again over 250miles.. it was a not a contact but the signal was heard. I have also recently heard of a QSO on 11m that was @ 300 miles.This is not fantasy but a reality.

 

[The20poundhammer]

I have a friend thats 50 miles away that we QSO regularly and we notice our signals at times will go up and down just like DX. Its not all the time but quite often it does. I have made contacts like this well over 200 miles quite often and we always referred to them as talking ground waves.

 

[AudioShockwav]

I used to talk to Robb on a regular basis on both 10 and 11 meters @ 100 miles plus out of my mobile up above Cathys Valley.
My brother lives approx 97 miles away and we talk almost every nite.
And yes, there are times that he is anywhere from S3 to S5 with no change in his power output or antenna.
This is one of the things that has always made "on the air" testing of different antennas have a, not a "set in stone" result up here.
Slight changes in band conditions, and other variables can cause fluctuations in signal readings very rapidly.

73
Jeff

 

[TheBlaster]

As Christophe refers to, there is no 11m ground wave as such.. but the term is occasionally used, enhanced line of sight is probably closer. There is most likely a little lift to somewhere for some hour of the day... just depends on being on at the right time at the right place.

 

[edfiero]

I was not able to reach them, but about a week ago, I heard my two longest ever, non-skip stations. One was in Connecticut (about 150 miles) and the other was in a mobile running 1000w crossing the Chesapeake Bay Bridge/Tunnel about (200 miles). At first I thought the mobile was skip, but 1. there were no other DX running, and 2. I heard a guy 75 miles south of me, trying to reach the same mobile, Definitely 'groundwave' for him. I am in the Philadelphia Suburbs.

I think I can routinely reach other base stations 60 to 70 miles away with my 4 element gizmotchy about 40 feet up.

 

[Joe_Mama]

As Christophe refers to, there is no 11m ground wave as such.. but the term is occasionally used, enhanced line of sight is probably closer. There is most likely a little lift to somewhere for some hour of the day... just depends on being on at the right time at the right place.

It's not groundwave, per se, true; it's called direct wave. 27MHz being just below VHF, it does travel considerably beyond line-of-sight, but doesn't follow the curvature of the earth very far, either. However, it does follow the curve to a degree. I routinely made 300 mile direct wave contacts using stacked Laser 500s and 2kw back in the 1990s. Even with a 4 watt radio, 90-100 miles was fairly common. But, 27MHz is unique in how it's near the bottom of where tropo enhancements take place, too.

 

[Blackcat630]

using stacked Laser 500s

Wow... got any pictures of that setup?

 

[groundwire]

200 miles. Island to island in hawaii. Every weekend night everyone would keydown and see whats up on each others island and talk.

 

[BJ radionut]

This is one of the things that has always made "on the air" testing of different antennas have a, not a "set in stone" result up here.
Slight changes in band conditions, and other variables can cause fluctuations in signal readings very rapidly.



Amend Brother! Enuf said!
All the Best
Gary