Cascadia dipole?

Whoever made this video made the contact from Drums, PA to someone in Tower City, PA.

Drums is at 1500 feet ASL, Tower City is around 780 feet ASL. So, effectively he's using a 720 foot antenna tower.

Note that my comment included a 'flat terrain' criterion.

 

Re that video and the few others posted that that all from same fellas...
Im sure i saw that it was said stock cobra at 1st but couldnt find it after..Then it was said there was some work on tec side but still talkin on a 4ft fibreglass ant useing an ole metal bodied kw....
Its cool to see that range on a cb but thats from the exclusive few who have a combo of luck and knowledge to get it..
It doesnt help the guys who driver newer trucks n such..
Doesnt help guys who cant modify their trucks
It doesnt help when two or three or four guys all say this works and that dont..

I for example bought or had made what was suggested,i would be into a small fortune without knowning if it helped or not...

Sux that the info here changes with who posts it..Typical trucker style info..We all look up at the same sky but everyone says its a different color..

Not saying any one poster is smarter than the next but for us who dont know,we get lost in the middle..

 

The guy that made the video was sitting on a mountain at 1500 feet elevation. The guy he was talking to was some 45 air miles southwest of him, at 780 feet elevation. They effectively had 'line of sight' conditions. It would be similar to having an antenna at 720 feet above the ground. 4 Watts can go a long way when both antennas can 'see' each other.

For reference, I communicated with the space shuttle Discovery on the STS-64 mission using a radio with 12 Watts transmit power attached to a 5/8 wave vertical whip antenna on a table in the back yard.

Antenna height is the single most important factor when it comes to distance, where line of sight radio communication is concerned.

Mods may make you cool, but they're not going to improve your radio's performance to any significant degree.

 

Well feel free to make my set up go further than about 8 mi max...A few here say the dipole is the way to go on these cascadias but in haveing issues trying to get a ground element to tune..

 

Gotta pretune the ground element off a known ground before you go further.

 

I tried telling him, but someone else told him that extension was the greatest thing since sliced bread.

 

I guess that partly explains why I can consistently reach the truck stops at exit 77 with my big radio...

 

What limits your range where CB frequencies are concerned is not your equipment, antenna, or even the vehicle that it's mounted on.

It's the Earth. More specifically, it's the thing that we call the horizon.

The frequency range that CB radios operate in is known as 'line of sight'. Which means that in all but a few very special circumstances, if the transmitting and receiving antennas can't 'see' each other without the horizon getting between them, then you're not going to be able to communicate.

Because the Earth is curved, the distance to the horizon for an observer at 10 feet above the surface is 3.9 miles. So roughly 4 miles. On a truck, your antenna is going to be about 10 feet above the ground. So, two antennas on trucks, 10 feet above the ground, will just barely be able to 'see' each other over the horizon if they are 8 miles apart. Any further than that, and they will drop below the horizon.

If one of them is higher, then the range increases. Say one of them is on a 400 foot hill. That will increase your distance from the horizon to 24.5 miles. Add the 4 miles for the other truck, and now you've got a 28.5 mile range.

In the video posted above, there's a 720 foot elevation difference. That would be a 33 mile line of sight to the horizon. Add the 4 miles for the 10 foot elevation of each truck's antennas, and you're at 41 miles - really close to the claimed 45 miles between the radios. I'll bet that if we knew the exact elevation of each of those antennas in the video, the line of sight equation would work out perfectly. The math doesn't lie.

Don't waste time or money on the 'perfect' rig and antenna. They'll all perform about the same if they're installed properly and in good working order.

 

Wow I've got a headache.

Disagree.

Sort of Disagree. It is the earth but not the way you are stating.

LoS isn't a HF issue.

This doesn't take place below 30 mhz, it is something that happens above that frequency.

The cb band - 26.9 to 27.4 is near the top end of the HF range and it depends on a few factors to achieve distance communications. One of them is called ground waves, which does happen at that frequency but it is normal to see it happen below 3 mhz, like in the 160m band and AM broadcast band - one reason there was something called a clear channel on the AM band.

However CB takes advantage of skywaves, and sometimes this can be bouncing off of the f1/f2 layers in the sky - which in some cases can be achieved with a NVIS antenna.

Line of sight takes place above the CB band, VHF and UHF is where this happens.

If this was only a LoS frequency, then ducting would take place, not wide band skip.

Again disagree.

Height has to do sometimes with the take off angle of the signal and how the signal propagates but it isn't a LoS issue with the band.

Absolutely disagree.