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CB and Anteanna Mounting


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  • 2 months later...
ok lets start with felt bottom bad

bummy ant. bad more than one not real bad but not the bestall that stuff screws with the ground plane whitch ever way u have more metal pointing away from the ant. the more u will talk and hear less metal less distance any bummy ant or extra ant. will cut a hole in a wedge shape in that direction that u can't talk or here from more than 200 feet

(if u mount it in on the back bumper u will talk forward but not behind u )

top dead center of vehical always the best as high as u can always at least 3/4 of ant. above roof line

and those springs he has are the worst thing to put on an ant.

cb's are the pickyest thing to set up and like he said get the match set

and the cobra 19 i have in my semi has a lil willy magnet mount ant. on it

and talks for ten miles with no power added

 

A felt pad isn't necessarily bad. But you would have to restore the ground via another method.(A Wilson Silver load antenna has a ground wire attached to it for just such instances)

Also a dummy antenna isn't necessarily bad either. You could actually put a series of cut dummies in and use them as parasitic directors and turn your truck into a enormous beam antenna.

 

A Comanche by it design is always going to have a radiation pattern that leans toward a front to back or back to front lobes rather than side to side.

(What that means to us, is that if you look at the truck. No matter where you mount the antenna you will get a larger 'lobe' or percentage of the useable signal going either to the back or the front of the truck rather than out to the sides.)

 

Load relief springs aren't the worst thing you can do to an antenna. That distinction would either go to the metallica paint that was on several Firestick antennas, the metallic flake in the plastic coating on some truck no-names, or those idiotic little lights that go on your antenna tips that operate via RF power.

 

The highest, top dead center of a vehicle GENERALLY is the optimum place for an antenna. In the real world its not always feasable. The fiberglass roofs of intergated sleepers on Volvo trucks, or rubber coated roofs on RV being two easily identified exceptions. Some vehicles also have keyless entry systems mounted in the overhead that will play havoc with the antenna system.

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this is the exact CB i have

 

cobra25ltd.JPG

it's not quite as clean, and i don't have the power cord for it, but it does work when i hook it up with a set of nipper wires. it's old.

 

 

That is an excellent radio. It is an older design Cobra, before the name was purchased by Maxon. The base design is still being produced by Uniden as the PC 66XL(whatever version is today's de joir)

 

When DynaScan(the corp that owned the Cobra brand name) went bankrupt, Maxon bought the name, Uniden bought the designs(and subsequently launched their XL line).

 

The Cobras produced today are either Chinese, or Indonesian in production and realistically not the same quality. Many are Maxon designs just repackaged to use their investment in the name.

Two quick examples are the HH-39(motorcycle) or the HH-40(handheld).

 

One thing noone has mentioned is to use QUALITY coax. Cheap coax without decent materials, construction or shielding makes your system just as bad.

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how do you calibrate a cb?

 

 

Most of the calibration involves adjusting the antenna. You will need a SWR meter from Radio Shack ($25 +/-) to do so. here's a good link that describes what is involved to calibrate: http://jeephorizons.com/tech/swr.html

 

It's not that hard, especially if you pick up a SWR meter and follow their steps rtft.gif .

Hope this helps.

 

very good link.

 

now i need a cb :oops:

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this is the exact CB i have

 

cobra25ltd.JPG

it's not quite as clean, and i don't have the power cord for it, but it does work when i hook it up with a set of nipper wires. it's old.

That is a nice unit, alot orf truckers use them, and they are still availible brand new, however, mostly found at truck stops. it is not your regular rat shack or wal mart level of quality found in those, but a much higher quality.

 

I need to get me one of them... jamminz.gif

 

 

 

 

i could get anyone on here that same exact CB in black i have it in my garage and would love to sell it!! pm me if your interested.

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  • 2 weeks later...

alright guys, need some help

 

i purchased a Cobra 25LTD... just like the one pictured about but the volume and squelch knobs are combined into one... (to replace the radioshack one i had that was stolen.)

 

and then i found out the coax line i had ran wasnt unplugged when they jacked the radio.. it was CUT! :headpop: grr don't get me started on theives... thats the 3rd time my trucks been attacked.

 

so i get this new radio the guy says, (local hobby shop thats been there for YEAAARS, real good ma'n'pap place) tells me he's got some that've been peaked out, he re-wired them himself to get the best performance from them. ok, i'll bite, so 10$ extra i get a peaked out one.

 

wire it up, new 18' coax line, same 102" whip never unmounted it, wired the radio in with my sub amp, and i had terrible interference like abad ground... so re-wired pos, neg both directly to the battery, and cleaned the terminals, still can't use the cb unless the truck is OFF, no key.

 

as soon as i put the key in and turn it to run (engine off) the noise starts like a door buzzer just nagging and the signal meter reads HALF! drives me nuts, so iturn the gain down and it goes away... yeah, ok but now i'm not picking up anything. gah, my brother's radioshack with 102" whip picks up 10x better. WTF?!?!!

 

help! i've tried grounding the radio itself by the mounting screw to frame with wire, i've done everything i can think of except have it tuned but thats not gonna stop interference.

 

oh, and when you touch the unit the sound diminishes slightly but is still there, and when i pull the mic out as far away from it as i can the noise is nearly gone... WHAT GIVES?

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Start with what turns on and uses electrical power when you insert the key and turn it to on.

 

1. Door buzzers

2. Fuel pump(a good chance your culprit)

3. Engine electrical system(relays and spark control)

 

make sure that you fuel pump has a good frame ground

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its NOT alternator noise is does it with the key in run, engine off.

 

fuel pump only primes then right? door buzzer does come through but the noise is still there when the door buzzer isnt on

 

so it could be something else has a bad groun and is makin the noise? cause the CB ground couldnt get any better

 

hobby shop is closed mondays.. grr!

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both door/seat belt buzzer and the fuel pump should only be an issue for a few seconds, so if it still makes the noise, say, 20 seconds after being turned to key on engine off (KOEO), then yea, time to start tracking other problems. ECU/TCU, and radio come to mind as creating draw in KOEO.

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