Hey everyone, I'm new here but have had my Jeep a while now.

Anyway I did the midland CB install from the site and im having a few problems.

when I turn the car power on it sounds normal but when I turn the engine on a high pitch whine comes from the CB.

I'm also having some problems with my SWR meter, and I'm not sure if I'm tuning it the right way. when its set to calibrate and I hold the trans. button the needle goes far right but nothing I do gets it to move to the left.

If pics of the meter and how I have the antenna mounted would help I'll get those up asap.

Thanks,
- Jud

 

Sounds like you're getting alternator whine...they make filters to help filter that noise out.

 

Like I just posted on another thread, find a good CB shop and have the radio peaked and tuned. A good shop will pull the covers off, hook it to an oscilliscope and dial it in. If your picking up engine noise, your ground may not be 100 %

 

I was trying to avoid having to go to a shop but i guess it will be done better than i can get it.

thanks

 

im gona get pics off all my connections and hopefully some one will see something i did wrong

 

Does your CB have a Gain knob? If so try to turn it down a bit. If mine is too high it'll pick up noises from my engine.

If turning the calibrate knob does nothing when you're SWR meter is set to calibrate and you're holding the transmit button there is definitely a problem. Like Putnam said that sounds most definitely like a short. Check your radio ground and your antennae mount ground.

 

Fresh out of the box, most CB's are off. What I mean by that is if Channel 19 is normally ....162.475 mhz, out of the box it could be +/- .025 mhz. Peaking and tuning will solve this. "Antenna Matching simply tunes it all in.

 

Heres the SWR I'm using, it also has a watt. matcher
http://i16.photobucket.com/albums/b4...p/DSCF0934.jpg
(sry for the blurry pic)

The way all my connections are is as fallows,

The ground for the CB connects to the bolt behind the dash cover (where it said to put in in the write up).

the lead goes directly to the battery.

I grounded my tailgate just as described in the write up, that is sand a patch of the paint off on both the tail gate and body and connect a 10 gauge wire to both spots.

I'm using one of those black plastic side body mounts (http://i16.photobucket.com/albums/b4...4/Jeep/m-2.jpg),

Its mounted to my stock tire carrier from the back side. the metal plate is on the other side of the tire carrier from the mount its self, a plastic spacer keeps the top bolt from making contact with the tire carrier and the bottom bolt (the ground) makes full contact with the tire carrier with the ground from the coax connected to it between the nut and lock washer. I also have a 5inch antenna spring and then the antenna.

I also noticed this the other day when I was standing near the antenna with just the car power on and the CB on there was no white noise but once I moved away from it by like 1-2 feet, it came back. Is that normal?

I've found a place that I may be able to have everything looked at but wont be able to get up to it for 4-5 weeks so if i can get this resolved before then on my own it would be great otherwise once I have a chance to go back home ill do it then at the shop.

 

If your body changes the level of white noise then it is changing the resonant frequency of the antenna. Verify one more time that it is not shorted. Where did you get your coax? Are you sure it is 50 ohm and not 75 ohm TV coax? Are the connectors properly installed? Has the cable been crushed or crimped in a tight turn? Any of these defects can produce expected results from a multi-meter but cause significant matching problems. Water in the coax is another culprit that is difficult to isolate! The device in the picture is a combination power meter and antenna tuner. It is not obvious from the picture, but read the instructions and make sure the antenna tuner is switched OUT of the circuit while you tune the antenna. With the power meter you can read forward or reverse power. Reverse power results from a poor match - energy that you wish to be radiated is reflected back toward the radio! You tune the antenna to minmize reverse power. If you really want to know the SWR value, after you have tuned the antenna to minimize reflected power, measure both forward and reflected power and use the calculator here http://www.ac6v.com/swrmeter.html. To tune the antenna, you need to adjust its electrical length. Depending upon the antenna this is done with a screw on the base or by physically extendng or retracting the whip. Since this is an AM transmitter, simply keying the microphone will not provide useful power output. Hopefully your radio has a TUNE switch which will transmit a tone at a level that will produce 80 to 100% modulation. If not, then you will have to whistle-up the output power by (guess what) whistling into the microphone. Hope you can whistle long time! Record the reflected power on Channel 19. Then tune to Channel 18 and record that value. If the reflected power on Ch 18 is LOWER than Ch 19 then your antenna is TOO LONG. If the reflected power is HIGHER than Ch 19 then your antena is TOO SHORT. Make adjustments in 1/8 to 1/4 inch increments. If you are unable to resolve any difference in Ch 19 and Ch 18 you may go to a lower channel, but it is possible that you might pass the resonant frequency of the antenna. Ch 19 is at 27.185 Mhz (NOT 162.185 as stated elsewhere.) If you aren't certain, another method is to record the reflected power at each channel from 19 down to 10 or so. If the reflected power drops along the way then then increases again, that indicates that the antenna is resonant at the point at which it dropped. I would suggest that you make friendly with a local amateur radio operator. This is no longer a sure thing (since no-code license was introduced) but he can provide probably help. Good luck!

 

Also remember to close your doors when checking the SWR.