will anything detrimental happen to my cb if i dont use an swr meter to tune it? it has a sensitivity thingy built in and i suppose you are to tune it using that? it is a cobra 18 or 19 plus II or something like that

not problemo!
there is a plasma coupling right at the deflector array junction that prevents the dilithim crystal bypass sequencing conduit from super heating avoiding potentail signal degradation during heavy ionic energy surges.
(I made that up)

Long time since I had a CB, but I think the meter fine tunes the signal for better and clearer reception. I remember when I had mine I didn't bother cause it was just something else to buy. Mine worked fine.

I would tune it using an SWR meter. I have the Cobra 19DX (predecessor to yours), and from experience you should tune it. Its very easy to do, easier if you have 2 people. Get the $20 SWR meter from Radio Shack. Tuning should take you less than 5 minutes. If your radio isn't tuned, you'll send and recieve poorly, and could damage your radio.

ok i need more posts alec says i could damage the radio and igottwo says it isnt a problem??????????

Hehehe, 920 posts to 47, I think I win :)

http://members.aol.com/riffman80/bounce.gif
D'oh! [img] code off.

anyway, J/K. Anyone else have some input?

well its in my car... i am not sure if it works...how can i test it????...it will recieve but when i transmit or so it says no one responds to me...ch 11 is from louisiana. agh help???????????????????????????????

Alec:
"quality not quantity is always the better measure and overarching consideration" (just kidding)
BUT...since it has been a while since I had a CB, I will respectfully defer to Senator "Alec" who holds +920 electroninc submissions to his favor.....sounds like that whole FL hanging chad thing starting over again! NOT!

Go with Alec or check out the manufacturer's has a site.

Stay with me on this one cause I may run the risk of sounding off the wall... or you all may even know it:
Some of the better technical research university web sites (MIT for one) have a lot of good papers and thesis available online e.g. electronics, even auto electronic systems. Best of all, they aren't trying to sell you anything.

By way of example: It would not surprise me if some guy has a paper out there on "The Effect of Sunspots on CB Radio Transmissions" and loaded up the front end of the paper with every nit and nat you need or don't need to know about CB radios.
Keeping this all in perspective and I know you just want the thing to work right, you may want to keep them mind if you are really stumped and or looking for creditable info to "tweak" that thing. (with the exception of here... naturally) It has worked for me many times. Who am I to agrue with MIT?
I heard that!... "why didn't you check it out before you opened your big mouth" haha
good luck and make it work

Jimabena 74:

If you have a new comercially made antenna such as a Radio Shack, Wilson, Hustler, Firestick, etc, and the coax cable is in good condition (not crimped or crushed, shorted, etc, you most likely won't DAMAGE your radio, by not tuning it. They come from the manufacturer approximately tuned. What you would be doing is fine tuning it for better performance, especially, transmit. Most modern solid state radios will just reduce their output power if the antenna is badly detuned. The stories of frying your radio with an imperfectly tuned antenna come from the old days of vacuum tube final power amplifier radios. Now, if your coax is shorted to ground near the radio or something like that, you might do some damage.

As for tuning for minimum SWR, this helps increase your transmit range by maximizing the forward power going to the antenna to be radiated as signal, and minimizing the reflected power returning to the radio from the antenna, as happens when the antenna is not well tuned.

The best way to find out if your radio is transmitting lacking a power / SWR meter is to have someone else with another radio, listen and move further and further away, while giving you signal reports. You shouild have 4-5 miles range, line of sight.

wow i havent tuned it yet but i already have a 2-3 mile range that is obstructed with several buildings. where i was located and where the other guy was located was in silicon valley california. lots of copmuters and stuff in the way too. i couldnt see his location from mine even with a telescope as there are 1 and 2 story buildings in the way. i plan on tuning it soon. my neighbor has a swr meter and he said hed let me borrow it when i brought back his torque wrench. he only lets me borrow one tool at a a time. my antenna is a 4 foot firestick II mounted on the roof rack with a spring. just a question, how can i get rid of or muffle the rfi on my cb? it is annoying!

Jimabena,

I assume the RFI you are talking about is a buzzing or whining sound. If this noise is constant, and not dependant on engine RPM, then it may be the fuel pump...a big problem in early Explorers There are several things you can do to decrease static, but you'll never get completely rid of it. I'm also assuming you can't turn up the squelch to get rid of it wuthout losing most signals. Anyhow, wiring your radio , both positive (red) and Negative (black) power leads directly to the battery is a good start. Also, Radio Shack has in line static filters that go in the positive power lead. You should fuse the power leads near the battery withn inline fuses,,and put about 3 to 4 twists per foot in the wires as they run through the engine compartment, to reduce inductive pick up of ignition system noise. As for the fuel pump noise, this comes in on the antenna line, not the power lines. Ford used to have a filter kit that installed right at the fuel pump, but since the pump is in the tank, it requires dropping the fuel tank. I installed one on mine, and it helped some, but it was a hassle. I don't remember the Ford part number for this filter kit, but if youre interested, do a search on radio noise, it has been published here on the site several times. The kit is discontinued, but a dealer may still have one in stock

A SWR meter is used in new antenna installations to trim the antenna to the proper frequencies. The SWR Meter measures the transmitted signal Standard Wave Ratio between Power out and Power Reflected back down the transmission line and lost as Heat. The ideal condition is that you want as much power radiated out of the antenna as possible. In a CB, since the power out is only 2 watts, this is very important to be transmitting as much signal as possible. Can you cause a problem to the CB if the SWR is too high? Not so much with newer radios as was posted earlier in this thread. But, you have RF power reflecting back into CB which can't be a good thing.

To tune the antenna and CB, I'd pick channel 20 as a tuning point since it is in the middle of the CB band. With the SWR Meter hooked between the CB and Antenna, key the mike to transmit. You want to see as low an SWR as possible. 1-1 is ideal. If you unkey the radio and go to channel 22 and key again, the SWR Should be higher than channel 20. Then do the same on Ch.18. That Swr should also be higher. This tells you that the null is around ch.20 for the antenna. The antennas are usually sold longer in SWR. If the null is in the high part of the channels, if you have a wire whip antenna, you need to cut off a very very small portion of the antenna and measure again above and below ch.20 to find where the null is.