CB tech

[Ryan_25]

Good points at the meeting last night for having a CB in your trail or road truck. Everyone should have one.

I have a space issue in the buggy. I do have a Cobra CB that was in the Samurai, but the antenna would not really work well on the buggy.

What options are available for a small antenna or a handheld CB radio?

Handheld would be a good option if the range was farther than 100 feet. Anyone have experiences with the handhelds? What are good units? The reviews I have read seem to indicate that a 100 yard max transmit range.

Dopple, your opinion would be most helpful. I know how to hook up the power and ground, but everything else is magic to me.

[smichaelR22]

magic indeeed

[rejeep]

I only use a hand held..  always have and always will..

I can check on the model I have, but it always works well, front of the line to the rear..  Face it, there is always somebody in the groups with a honking 1970\'s CB and field antenna close by.. and nowadays.. EVERYBODY has a cell phone, 75% have Verizon..

IMHO, a CB can easily be replaced by good walk talkies to communicate with your own party..  Saves on space and you can remove from your rig and walk up and down the line..

[ollllllo]

I have Yea walkie talkies are a good backup option, etk300ex and I always have a pair in our tow rigs to offer anyone who didn\'t have a cb. But as was the case this past weekend, all of my rechargable batteries died by Saturday midday.

in my superduty I have the cobra CB that has all the controls on the mic
I don\'t recall the model but its the black one and it seems to work fine. Perfect for a buggy. Then if you want to remove it for a competition, you. Would have nothing in the way. Just unscrew the mic. 99.00 amazon.com

I need some help w set up as well, I can hear interference through my CB when I hit the horn. And the range sucks.

[MrMindless]

I hear my horn too, but it doesn\'t bother me.  filter on the power should take care of it.

for the buggy antennae, I\'d suggest a base loaded steel whip, and keep the base below roll exposure but as high as possible.  probably best odds on roll survival.

[etk300ex]

IMHO, a CB can easily be replaced by good walk talkies to communicate with your own party..  Saves on space and you can remove from your rig and walk up and down the line..

I couldnt agree more!  You cant beat the dependability and simplicity of a walkie talkie.  CB\'s are just such a pain in the butt to install, tune, and maintain IMO.  Only problem with walkie talkies is the batteries, but I always carry extra with me, mine have a battery meter right on them aswell.

[Wingman]

I generally do both.  CB in the ride and a handheld when I step out.  Besides, the handheld is hard to hear with road noise, etc.

[Camo1Ton]

I carry both as well. Just can\'t hear em above idle, damn Cherry bombs.lol

[MrMindless]

I always fight to hear cheesy handhelds - and no external speaker option.... Then lose them in the cab when I get back in, etc.

[Dragon]

ollllllo wrote:
in my superduty I have the cobra CB that has all the controls on the mic
I don\'t recall the model but its the black one and it seems to work fine.

It\'s the Cobra 75WSXT.  It\'s a nice compact CB, has decent volume, and with the right antenna can give good range.  It\'s what I\'m running in the JK now, with a 4\' Firestick.
The base unit has a port for external speaker.

What I like most about it is you can unplug the mic and lock it away somewhere when you have the top and doors off the Jeep.

[ollllllo]

I\'m planning to hook up external speaker. Difficult to hear when the turbo  is spooled up. When I turn the volume to max the sound is distorted and hard to understand as well.

But other than that I like it very much, just need longer antenna

[Ryan_25]

Dopple when are you going to set up a CB tuning session?  :-)

[MrMindless]

I can assist too - and sometime after RCQ...

[Doppleganger]

As far as being a pain to install... I have no idea how anyone could say that.  Someone change the oil pan on my bronco, I\'ll install your CB.  Let me know how that goes.

There\'s no magic to it, really.  The radio sends an electrical signal down a wire (your coax) to the antenna, and makes it resonate at a certain frequency.  That signal flies thru the air, gets to any other antennas, and is picked up by receivers who turn it into an audio signal suitable for humans to hear.

Before a tuning session, everyone needs an install session.  The best place to hook up the power and ground is directly to the battery, and make sure the battery is grounded to the chassis, body, and engine.  That will help keep ground loops at bay.  On the antenna side, I\'m assuming everyone is going to use a hard mount somewhere.  The mount must be grounded to the body of the vehicle (see where the battery ground to body is important?).  The coax shield is also connected to ground there.  The center conductor of the coax MUST be insulated from the ground usually thru a nylon washer, or though a better quality mount that passes the SO-239 (female) portion of the UHF connector thru the mount.  Wilson antennas also have an impedance matching coil in the bottom of their fiberglass and flex antennas.  That should be attached to ground, also.  It matches the antenna impedance to the feedline (coax) impedance to lower your SWR.  It\'s a good idea to use it, and another reason I like Wilson antennas.

I have a Wilson 1000 mounted to the roof of the Bronco.  It\'s up out of the way, doesn\'t hit anyone, takes a beating, and still has a 1.2:1 maximum SWR across the entire 450KHz bandwidth of the CB band.  The CB band is REALLY narrow compared to other radio bands, so getting an antenna that works well across it should be easy to do.

SWR is Standing Wave Ratio.  Simply, it\'s a measure of how well the length of your antenna is tuned to the frequency you\'re transmitting on.  The lower the better.  Think of it as having a tuned exhaust that scavenges very well.  The exhaust will flow and not restrict the engine.  When your SWR is low, most of the signal is making it out of the antenna, when it\'s high, a portion of the signal gets reflected back into the radio, which, in turn, heats up the final transistors and can lead to premature radio failure.

Your antenna\'s length is a fraction of the actual wavelength of the frequency you\'re using.  Usually 1/4 of it.  Because of the low frequency of the CB band, most antennas are fairly poor performers, just the nature of the beast.  Also, because CB radio is below 30mhz, the signals can bounce of the ionosphere, and come back down to earth hundreds or thousands of miles away.  For local communications during high solar activity cycles, it\'s not optimal.

So, let\'s pick the frequency for Channel 16, 27.155MHz.  A full wavelength antenna is over 34 feet.  A quarter wave antenna is 8\' 7.5\".  A straight antenna that tall would work fairly well, (not as good as a 1/2 wave antenna, though) but nobody will do that.  So, manufacturers coil the wire on the antenna to shorten it\'s overall length.  It has the same effect as running a coiled exhaust.  The shorter the antenna, the tighter wound the coil will be, and the performance will suffer.

Running a 4 or 5 foot antenna will probably be all that anyone will run.  Mount it as high as you can.  Having the antenna next to ground will hurt performance.  If you insist on running a heavy fiberglass antenna, RUN A SPRING ON IT.  The bottom of the antenna WILL eventually fail from flexing.  This is why I usually avoid fiberglass antennas.  A spring stainless steel antenna will take a lot more abuse, and won\'t need a spring on the bottom.

Coax needs to be un-kinked, un-cut, and in good shape.  Ends should be soldered on, and if your mount has an PL-259/SO-239 connection, wrap it in weatherproof coax seal.  Moisture in your coax will wreck it.  Coax is cheap, if you can afford gas, you can afford coax.  RG-58 is just fine for everyone.  RG-8X is a tiny bit thicker, a little better performance, but I doubt anyone would notice.  Just make sure that it\'s at least 95% braided shield.  Soldering connectors is about as tough as changing spark plugs, and you won\'t bang yer knuckles.  Don\'t coil up your extra coax length, either shape it in a figure-8, or just randomly stuff it under the dash.  Coils are inductors, and unless you\'re using a coil of coax to tune your antenna system (like with a j-pole antenna), they\'re not wanted.

I never have any issues being heard on the trail, I run a Uniden PC78LTW in the Bronco, which has been slightly modded, and a Wilson 1000 roof mount antenna, and an Astatic Road Devil mic.  I have about $160 into it, so it\'s a pretty cheap setup.  I thought about putting a SSB (Single Sideband) rig in there, but since Snort sold his, it\'s kinda useless.

Next Post... UHF FRS radios.

[Doppleganger]

The Cobra 75\'s are basically a HH45WX walkie-talkie without the battery.  They\'re ok if you have no other options, but because of the compact-ness of the unit, I wouldn\'t expect it to last as long as a standard radio.  Less room for heat to dissipate.

I still think for buying a new/refurb radio, if you want something small, that performs well, and seems to stand up to a beating, the Uniden Pro510XL is tough to beat.

I generally have a better opinion of Uniden radios over Cobra radios.  The build quality has been better ever since Cobra stopped having Uniden make their radios.  Cobra moved manufacturing to China, and Uniden (have to re-check this) was in the Philippines.

Hand held CB\'s inside a vehicle work about 1/4 as well as anything hooked to a vehicle-mounted antenna.  The short antennas on them pretty much suck for anything but really close contact.

FRS/GMRS radios work better inside a vehicle, as the wavelengh is <70cm, and can penetrate your windows, or gaps in the body/roll cage better.  But still, it\'s a handheld antenna.  Designed to be \"stylish\" and not \"optimal\".  They\'re ok as long as the trees aren\'t too wet, and you\'re not trying to transmit over a hill.  The higher the frequency, the less the signal will bend over terrain.

You\'re probably not using it legally, either.  Read the owner\'s manual for more info on GMRS licenses, maximum power output, etc.

\"5 mile\", \"10 mile\", \"28 mile\"... yea, you\'re not using them between boats over water.  If you get 5 miles out of your 5 mile radio, then I have a championship winning desert racer to sell you.