how much does coax matter?

Factory coax is probably no worse than the crap you buy in the truck stop, and in fact may be better.

The problem is that most trucks use a splitter to feed the in-dash stereo, as well as the TV antenna. Shove 100W into that splitter, and you'll smoke it (and maybe your radio) in short order.

Use a mirror mount or bird perch, and feed it with its own coax. I use the passenger side, since I rarely open the door.

He said he had "a 100 watt radio". Nowhere did he say he used it on CB. I have a legal 100W radio in my truck, too. My radio will run just fine on CB, but I don't use it there. Aside from legal reasons, the filtering in the receiver is too good; I can't copy the "loud and proud" guys that are splattering across several channels. I had a nice chat with a guy in Slovenia recently on 14 MHz.

Yes, I have my ham radio license.

 

CB's runs mostly on AM which "bounces" off the Ionosphere for hopping.
SSB is AM, but strips the carrier only using the single or both (lsb,usb) for transmissions.
FM is line of sight.

http://www.navymars.org/national/training/nmo_courses/nmoc/module17/14189_ch2.pdf

 

Anyone who tells you that a stock Cobra is going to talk as well as a well tned big radio should gag on the lies out of there mouth.

I own A RCI 2950 and a Galaxy 95t, there is no stock 4 watt radio that is going to talk as well, just not going to happen. I do not run them in my truck, I run a stock nightwatch in the KW, But it surely does not out talk the RCI or the Galaxy.

As far as coax, I dont find a problem with most of the coax in the truckstop, but the connectors are frequently not installed correctly. I would order RG142u and that is what I run in the truck. I also use silver pl259 teflon insulator. I run a single antenna on the trivers miror, keeps trees from removing it. Good luck stay safe.

 

100 watt "big radio" talking on all factory antenna on say a Cascadia or something....yeah...5 miles

3 watt "mudduck" radio on some good Mini 8 and a 102 whip............10 miles maybe more. Done it plenty of times, driver.

 

Quite possibly out of your price range...

 

Negative....I would prefer the stuff at the truck stop over factory. As matter a fact, With all the trucks I have ever ran, I never had a truck with par factory antenna systems. I've always had to put my own mount and coax.

 

I drove a Cascadia and a Columbia, I used the factory antenna mounts, but I ran RG142u to the antenna on both trucks, used the left mount for my radio and the right mount for theirs. Good match, no problems. And I would run my Ranger, the difference was those trucks parked in my back yard.

The only reason I use a Cobra in the KW, is the size of the hole and the owner ask me not to install the other radios. I still changed the coax to RG142u.

If you want to take the time to trace out the factory coax, make sure the multiple connections are clean , tight and secured , tune the antenna coupler they will work very well on any radio 10 watts or less.

As far as arguing over your 4 watt radio over powering a 200 watt radio save it for the newb's. Because we already figured out the laws of physics are different for you.

I do agree that a 102 whip sitting in a HD springs is one on the best antennas, just not practical on the mirror of a KW. As far as

Good luck besafe. Mini 8 I think has too much loss at higher freqs. I need my coax to be able to handle up to 1.2 sp for my applications I can not use an inferior cable.

To the headache rack i ran Andrews Superflex Heliax.

 

Look at coax like a fuel line .
If you cant enough fuel to the engine it wont put out the power it should .
Your wattage is the same way if it cant get to the antenna.
4 watts or 400 its all the same .

That is why a well tuned 4 watt setup will out perform a poorly tuned 400 watt set up .
It makes no sense to me to pay 300 to 500 bucks for a radio and then not maximize the rest of the system.
If drivers would spend more time tuning antennas and getting good coax and less money doing golden screwdriver mods they would have allot better sounding and performing radios .

I know the companies and all the other excuses out there but the fact is still bad antenna and coax = bad performance .

 

Bravo!!

It is?

Nope it isn't line of sight.

You're funny Mark, FM is line of sight ...

Using 142? it is an overkill, you are not trying to bounce signals off the moon or bounce off of the meteor scatter. Silver PL's? just get good old plain jane connectors that need to be soldered, don't bother with teflon ones unless you know what your doing.

 

It's important to differentiate mode and frequency range. Modes, as in "how the carrier (if any) is being modulated) like FM, AM, SSB, DSB, (and, for the more esoteric hobbyists, Fast Scan Television, Slow Scan Television, Radioteletype ["RTTY"], and even old Morse Code as a way of getting information onto an interrupted carrier wave, can all be used regardless of the frequency. Well, there are regulations keeping the modes that take up more bandwidth on higher frequency ranges where there is more bandwidth available.

Generally speaking, it is the frequency upon which one operates that determines whether a signal is primarily line-of-sight. And generally, the higher you go in frequency, the more likely it is to rely upon line-of-sight to have successful communications.

Without getting into a long dissertation about what constitutes sky wave vs. space wave vs. tropospheric ducting vs. ground wave, suffice it to say that, regulations aside, whatever you do at 145 MHz (Morse, AM, FM, SSB, P25 digital, etc.) is going to perform about the same as any other mode at that frequency band. Yes, I know that a half-watt of CW Morse can usually be heard farther away than nearly any other non-computer-based mode, but my point is that the signals will be affected in the same manner and to the same extent regardless of the mode chosen.

To say that FM is line of sight assumes a couple of things that most non-radio enthusiasts (or professionals) wouldn't know. If Mark meant the U.S. FM Broadcast band, i.e., 88-108 MHz, then his blanket statement is substantially correct. Not many things affect the range of broadcast FM signals, except for large reflective or absorbent structures (tall concrete & steel buildings, large earthworks, or sometimes just enough green growth in a forest. Since time of day doesn't affect any of the tropospheric layers that bend, reflect, or absorb radio waves in that band, FM broadcasters usually don't have time-of-day operating power limits. AM broadcasters, on the other hand, may have daytime power limits of 2,500 watts but nighttime have to turn down to under 100 watts, as their relatively long wavelentghs are affected greatly by time of day.

But I digress; I'm old, so I do that a lot. Within the CB band (yes, I know, that's redundant -- "Citizens Band Band...."), several things affect range over which we have some control: operating practice, front panel adjustments, technician enhancements (or "ruinments"), making sure the coax is the right impedance for the antenna (50 ohms for a single antenna, 72 ohms for "co-phased" antenna pairs), correctly applied connectors, and proper antenna installation with a counterpoise immediately under the feedpoint for the antenna. Factors over which we have no control include where we are in the nominal 11 year sunspot cycle, time of year, and time day. A box-stock CB rig, without having anything done to it, is more likely than not to be at or near the best it will run. Even with the get-'em-out-the-door mentality at manufacturers who may be OEMing radios for a dozen brands, they still have to get the radios close enough to "right" to keep down the in-warranty returns. So while there may be a way to strangle another half-watt or so out of a transmitter and *not* make the radio audible up and down the band 8 or 10 channels, most such tweaks will make the final(s) draw enough extra current that the parts may wear out (translation: burn up) sooner than a radio that's not subjected to such a "tweak and peak". Speaking of which, anyone ever get their radio tweaked but *not* peaked? Or are those terms like "kit & kaboodle"? I've got over 50 years' experience working on transmitters & receivers (yes, with the appropriate licenses) so I somewhat self-righteously refer to what I do as "aligning a radio" -- to factory specs. But take a radio from my bench and plug it into a stock Cascadia, with its diplexer(s) to make several items run off the same odd pair of antennas through questionable coax and without any counterpoise at all in the cab, and even that radio that's great on the bench will be at the mercy of the folks who built the truck, and who put the CB performance at the bottom of their priority list.

With anything under 50 watts and 50 MHz, you can be just fine with decent RG-58 coax. Avoid the 18-foot myth and use enough line to reach from the radio to the antenna, plus a foot at each end to allow for the inevitable connector replacement after the owner keeps putting in an SWR meter over and over to "check his SWRs" every time he fires up the truck. There's no need for RG-8 (or RG-213, nearly the same thing) unless you're running over around 600 watts, or over 100 feet to the antenna.

Hope that helps clear up some of the terms that are bandied about somewhat loosely here.

73