how much does coax matter?

Thanks, Mark. FWIW, I do hold an Advanced class amateur radio license, and am familiar with ionospheric radio wave propagation. Amplitude Modulated signals in the 27MHz band (CB) are most of the time, in fact, essentially line of sight communication - unless conditions are right for ionospheric propagation. Ground wave propagation may add a mile or two beyond line of sight, but cannot be relied upon. Without getting into technical details, the typical radio / antenna system in a truck is not ideal for taking advantage of ionospheric propagation. And drivers are mainly concerned with using the CB to either find out whether that next chicken coop is open or closed, or playing CB Rambo in the truck stop parking lot. While a 100 Watt radio will not help with the former, it will go a long way towards achieving the latter goal.

Also, these truckers that angle their antennas forward 45 degrees to 'look cool' are actually cutting their transmit / receive distance by at least half, if not more, due to antenna polarization mismatches.

 

OP, I'll chime in....

Think of coax like a water hose. You can buy cheap water hose and you can buy high quality water hose.

The cheap water hose will blow a hole (or two....or three....) and "leak" water, while the top quality hose will not burst and will last for years.

In the case of coax, the cheap stuff might work ok for a stock 4 watt radio...but start adding power and it will "leak" RF. The more you add, the more it leaks.

The good coax OTOH is better shielded, and won't leak as much. It will also take more punishment.

When it comes to getting the most out of your radio, 1. you NEED a GOOD antenna and 2. you NEED GOOD coax.

Running power on a cheap antenna and cheap coax = a bandaid. Especially when the guy with the little Cobra 19, the LMR-400UF and the 5 foot tall Wilson 2k, is walking neck to neck with the guy with the Galaxy 98VHP, the RG58A/U and the 3 foot tall Firestick/Francis/Barjan fiberglass whip.

Now...dB loss of coax is typically measured in 100 ft.....but you still don't want to skimp out on cheap coax. The LMR-400UF I quoted runs about $1.85 a foot, everything else is cheaper. And you only need enough to get from the radio to the antenna. Despite what you heard, "18 ft." is not required, unless you need it.

 

A lot of guys out there do tilt the antenna in an effort to resemble a bull with horns or some look they deem cool, but a lot of guys can't get a decent SWR without having the antenna stretched out. That could be fixed, but they go the easy route.

 

Using the passenger side for your mirror mounted antenna will cost you your antenna. Low hanging trees in areas around shippers or on small roads will claim it as their own.

 

In response to the one saying 4 watts will do as good as 100 watts: Sir, with all due respect, you need to stay in your front yard. It is obvious you are not a serious radio user. I will talk 8 t0 10 miles during "train wreck" skip and 20 to 30 miles with lower noise levels in most other terrain. Small example- Trinidad Co. to Raton, New Mexico (over Raton Pass) is common for me. Your stated information shows your lack of practical experience. Have a good day, sir.

 

I have to call BS on this. With the center of the CB antenna (on both ends) up about 10' off the ground, you have a maximum groundwave distance of about 9 miles. This distance extends with the square of the height; 50' (on both ends) will get you 20 miles. So, the only way to get 20 miles is to have both stations 50' above the terrain in between them. (One station 100' above will work, as well.)

Put another way... you are NOT going to get 20-30 miles unless one (or both) of you are on a hill.

 

Call it what you want with all you desktop calculations. I do it every day between Ft. Worth, Tx., Trinidad Co and Midland, Texas. My point was it is SO ridiculous the guy saying a four watter will talk as good as a 100 watter.

 

I look at it this way you can buy a very expensive stereo but if you look it up with cheap wires to cheap speakers you will never sound as good as the guy that bought the same expensive stereo but hooked it up with high-quality cables and high quality speakers.
And drivers a little bit of advice here stop slamming the doors on yer coax you're such a rookie when you do that, take 15 minutes out of your day and do it right.

 

What you reference here are unique conditions, where you are trying to overpower the effects of long range ionospheric propagation, or taking advantage of knife edge diffraction. My comments were pertaining mainly to flat, level terrain mobile-to-mobile communications. Which covers the majority of CDL driver experiences with radio propagation.

 

Sir with all due respect for your technical knowledge, I do not disagree with your statement at all. I think we may both making true statements. My whole point was that I consistently talk farther than a 4 watt radio regardless if the environment situation is unique or not. This was all to a statement made by someone else earlier in the thread.