Baffled by the range claims

Why is it that 99% of the time I'll be able to hear you even if you're on the opposite side of a mountain from my present location?

 

Ridgeline, thanks for taking the time to offer us that great tutorial!

I'm shallowly aware of the theories about how RF signals travel, e.g. ground waves with their surface waves, direct space line-of-sight waves and occasionally waves taking a free ride into the troposphere. And then, of course, there are the opportunistic bits of RF energy that take the really big ride into the ionosphere when conditions allow a 27mhz trip for hundreds or even thousands of miles, at least for a while.

However, I often revert to the line-of-sight term when I see reports about extraordinary distances being regularly claimed for our mobile rigs. It is my belief that our truck rigs are confined close to what the line-of-sight factor is in terms of distance. So when a rig is on a hilltop talking to another rig on a hilltop, it can often achieve distances far in excess of what it can achieve when they are on level ground. And when they are on level ground, they generally aren't going to get much more than what the line-of-sight distance is, and maybe not even that when the ground between them is not favorable for RF signal propagation.

In this way, I'm hoping to keep those who are frustrated that their radios aren't performing as well as some reports indicate from throwing away their radios. Generally, the CB isn't going to do much better than the line-of-sight distances, which is much shorter than some of the reports out there.

And Rabbi, about your through-the-mountains signals, I'll just have to chock that down as exceptional. I can't explain that, no matter who tunes the radio.

 

That's true under a different set of conditions but not under identical conditions. You have to look up the GPS coordinates of both stations and situate yourself at one of those locations and have another station at the other location in order to make a comparison. Just because you can talk twice the distance in the Flatlands of Indiana doesn't mean you can talk twice the distance in the mountainous Terrain of Pennsylvania.

As you get further away your signal gets weaker and as you drop down the opposite side of a mountain your signal gets weaker and if I can still hear you and no one else can even though we're all sitting in the same parking lot obviously the tune would be the deciding factor assuming the other people in the parking lot are driving a vehicle similar to mine with an antenna installation similar to mine.

 

You're welcome but I would not go as far as to claim it as a tutorial, just an informative post.

I was taught by an old time radio operator who was around when Marconi was still young this saying -

RF is an unpredictable creature.

 

Hmmmm. Sounds like women are actually made of RF. That would make some sense.

 

That dame. Rilly Freaky.

 

For a minute there I thought you were dead. I watched this video on Monday and feared the worst.

 

Boy for a minute there I thought you actually took yourself seriously.

 

Not a chance. CB shouldn’t ever be serious. Just flip a switch and cut a duck’s lips off.