CB phenomenon?

[lugueto]

While on my most recent trip on the southernmost part of the country (Venezuela), I was travelling with 6 buddies on 3 trucks, all of which had CB's. My antenna is 400watts, a buddy's 800w and the third one a 1000w antenna. The radios functiones perfectly and had good range, we were using channel 10 at first, then it got crowded we flipped to channel 11.

When on channel 11 I started getting some weird interference that later became clear communication. Weird thing is, the communications turned out being two english-speaking truckers. This struck me as odd as I can guarantee theres not a single american in, at least, a 200 mile radius. Listening in, they started to mention Columbia and the I26, my memory kicked in and I realized they were in South Carolina.

How the HELL can I hear a bunch of truckers from south carolina being, approximately, 2150miles away ?????? lol

Also, weirder yet, neither of my buddies could hear them, using the same channel and having more powerful antennas. Why is this??

Cheers

 

[1911]

Because the 11-meter wavelength of CB will propagate via "skywave", i.e. signals can be refracted by charged ions in the ionosphere. We are currently in a sunspot cycle that is charging the ionosphere so conditions are frequently favorable for this type of propagation in the appropriate bands.

Antenna performance is not rated in Watts, it is rated in dBi or dBd of gain. Your antenna was more perfectly-resonant on Channel 11 (27.085 MHz in the U.S.) than your buddies. This is a matter of electrical length, not of how much power the antenna will radiate.

 

[SanDiegoCruiser]

^^Nice call sign! Mine is N6MUD!

 

[1911]

^^Nice call sign! Mine is N6MUD!

Thanks; I think I commented in your thread that I liked yours too!

 

[Elbert]

many companies do give a rating as to how many watts their CB antenna is suppose to be able to handle...don't know if there is any standard as to how this calculated but I've seen it expressed on web sites and various literature.

I think in the old days the condition that is referred to by the OP was called "SKIP"....in that the reference was that the signal would bounce or skip off the atmosphere ...

 

[1911]

many companies do give a rating as to how many watts their CB antenna is suppose to be able to handle...don't know if there is any standard as to how this calculated but I've seen it expressed on web sites and various literature.

OK, but how many watts of power it is capable of radiating has absolutely nothing to do with how efficient it is.

I think in the old days the condition that is referred to by the OP was called "SKIP"....in that the reference was that the signal would bounce or skip off the atmosphere ...

cb'ers still call it "skip" to this day as far as I know...

 

[lugueto]

Interesting, learned a couple of things today. thanks for your replies!!

 

[Elbert]

OK, but how many watts of power it is capable of radiating has absolutely nothing to do with how efficient it is.



cb'ers still call it "skip" to this day as far as I know...

yea...maybe the OP mis-understood the rating vs what is applied.

 

[prado t]

C.B. radio skip. Since the late 80s we would shoot skip. I have been able to talk to people in Tennasee and North Carolina and Southern California from central British Columbia using a 4watt C.B. and 1/4 wave antennae.

 

[Tapage]

important component of that propagation range are the 100W amps that most of truckers have .. besides really well tuned antennas ..

 

[rusty_tlc]

important component of that propagation range are the 100W amps that most of truckers have .. besides really well tuned antennas ..

Not necessarily, a lot of hams operate QRP (low power<5W) and do DX (long distance) contesting. Skip or sky wave propagation is more about atmospheric conditions.

 

[canucksafari]

Skip or sky wave propagation is more about atmospheric conditions.

and those conditions will keep on getting better for the next 5 years given the solar cycle.

 

[lcolon]

Take a look at this for a little flash movie on propagation:

Propagation Primer - Flash Movie by AE4RV

Just remember that in the US - running an amp for CB is illegal and can net you a pretty big fine from the FCC. If you want to run power - spend a few hours getting your ham radio license and the $15 or so fee to take the test and get registered. You can then run 1500W legally (although I probably would not do that in a mobile installation)

Just last weekend I was talking to a guy from Vancouver Island, BC Canada from the bay area, on my mobile HF Install 20m, in my cruiser, with the radio set to only 50w. Pretty amazing stuff. At the same time there was a station coming in from Germany clear as a bell. Propagation is cool especially now that our sun is ionizing the atmosphere nicely for the first time in a while.

I still have a CB in my truck, use it on the road and with fellow 4wheelers who only have that available, but the HF ham bands are truly incredible.

AF6GS

Luis

 

[lugueto]

It happened again a couple of weekends ago on a trip, this time not as far south. Again I was the only car in a 4 car convoy that could hear them, and I could hear them clear as I heard my buddies.

Proud of my CB. Bought it only for the convoy purposes, cheapest one amongst my friends and the most powerful one? win.

What's a HAM radio?? is that like the UHF the aussies use?? Ive never seen anyone use UHF here in Venezuela, VHF is rather common although licenses are a pain to get.

 

[1911]

What's a HAM radio?? is that like the UHF the aussies use?? Ive never seen anyone use UHF here in Venezuela, VHF is rather common although licenses are a pain to get.

"Ham" radio is amateur (i.e., non-commercial) radio that requires a license to use and has privileges on many bands in HF, VHF, and UHF, depending on the licensing level and the country issuing the license. Besides privileges in many bands, you are also allowed to use vastly more power than CB. In the U.S., the large majority of ham radio trail/convoy communication is on the 2 Meters VHF band.