Antenna I want to use a c.b. antenna for my f.m. radio . Do I need to modify the antenna, or radio, or cable. The cable will need to be spiced or addapted from coax to reach and fit into the radio. also the c.b. antenna mount is mounted into the side of the fiberglass tub of a dune buggie, will the antenna need to be gounded to the frame?

yes, but no. The radio is designed for low power and a short antenna to limit range. This was to reduce interference with Licensed FCC radios. Since I will provide a few ideas, these are to experiment with radio waves, NEVER to break the law. So.....ideas to increase antenna: most simple, tape coax to the antenna lead. It will pick up a small amount of the radiated signal and sent it to the longer antenna. Strip the rubber and even the mesh, the center copper sends the signal. Best if under 10 feet. Other than this, you either cut open the rubber antenna or best of all, open the radio and soldier to the antenna connection on the main board. Remember: low power radios cannot send a signal far. Use good quality coax, RG58, never cable TV coax. Short length has a better opportunity of working. 30' you will lost all the signal in the coax. Other ideas? Yep, lots. email us. :)

You'll need to decide what style of antenna to use first. Once the antenna is mounted and the coax is run from the radio location to the antenna. Use a SWR meter to tune the antenna to the radio. Use ONLY 50 ohm coax not the coax used for cable TV. If you hear spark plug noise in the radio, then install a choke in series with the power wire. It's best to locate a wire in the fuse box that is only powered when the ignition switch is on or in the accessory position so the battery wont run down if you forget to turn off the radio.

It apparently has been worked on hence you knowing it is squealing ie talkback. It's the usual checks antenna system check your ground for mount on metal to body of vehicle. Check coax pinched in door or damaged. Check the insulator is on top of Mount for antenna remembering antenna positive and ground shield is going thru mount to body. It would not hurt to check swr reading with another know good functioning radio. The squeal is often caused by RF feed back but power lead or speaker leads or coaxial cable ran near one another can do the same. Now for the pessimistic view if it has been modified yoru modulation may be to high for the gain(sensitivity) of microphone you are using which if you can turn mic gain down on radio it is not a problem but if you have not got enough range of adjustment it may have to be done internally or go with a lower gain mic. Modified radios do not play well with power mics they are marketed for the unmodified CB radios.

I have a wilson 5000 mirror mount. I mount it on the drivers side mirror on the upper cross arm that goes to the mirror. It is mounted on this arm with a bracket and a so 239 connector so I can undo it if I have to ,leaving the antenna connected.I can change coax and not have to worry about undoing the antenna. Remember one thing. The antenna has to be checked for SWR.each time you move it to a different spot or to a different truck.

Hello cktmn,
Welcome to FixYa.
My name is John, and I will be assisting you with your issue today.
Yes, the K40 is a great antenna for that radio and it should come with the COAX on it.
It is a magnet mount and the best place to put it is on the top of the vehicle or the center of the trunk. You will be surprised as to how well it works.
I hope this was helpful to you and thanks for choosing FixYa today and in the future.
Your comments are always welcomed here.

John

when mic is pressed transmitter is engaged. First is the Fuse the proper fuse? Could be an antenna-coax problem. Get a dummy load and hook up to your CB and try it again. If it doesn't blow the fuse, the problem is indeed in your coax antenna system. another way to test your antenna coax is to disconnect it from the radio, take a multimeter, set it to ohms 200 ohm scale, put one lead on the center pin of the coax and the other on the outside of the connector on the coax.if it shows anything at all, you have a short and that will not work. It needs to not read anything. To be sure the antenna system is ok other than swr you can also check the coax an antenna for continuity. one lead of meter on the coax center pin then other on the antenna. should get a reading, a low value. again on the outside of the coax at the connector and at the antenna side on the outside of the coax connector. should be a low reading. but you cannot have a reading from the center of the coax to the outside of the coax. disconnect the coax at the antenna and measure from center to outside at the coax if the previous reading showed a value.If you see a value on the meter, any value, your coax has a short. not good. most likely at the coax connector. redo the connector. It is possible that the coax got compromised somehow and got smashed to the point the outside coax meets the inside and touches.
Now the other possibily your fuse blows, kis because the final output transistor is bad. So if you hook up a dummy load to your radio and the fuse still blows, then the final transistor is bad. This is probably due to a bad coax-antenna system. So before you replace any parts check the coax-antenna system first or you will have the same problem and burn out another transistor in the final. If none of this helps then just get another radio or have a god buddy look at it that knows about radios. Trade him another radio or something to fix it.

As for me ,the Wilson 1000 or Wilson 2000 are the best mobile antenna for a mobile. I have out talked a lot of base antennas with them, just put it on the top of car in the center or trunk, or middle of cab of truck, with a good SWR and you are talking and receiving. great antenna. ...hope this helps..

Having that short a range would give me the indication that there is a disconnect in the antenna system. Here's a couple of clues: Is the connector on the back of the radio connected to the coaxial cable?

If it is not factory installed connector, is it possible that the solder job on that connector was bad? If the cable is old, it could have a crack in the coax.

Is it the RIGHT kind of coax? It should be an RG-8, and RG-58, or a variation of those types of cable. It would likely be marked with "50 Ohm" somewhere along it's length.

Is the connection at the antenna solid? A firestick antenna for CB looks like this:


You must make a good connection at the base of the antenna from the center coax conductor that does NOT short it to ground, and the ground conductor should attach to the antenna mount frame.

With your symptoms, it is very likely that either the center conductor has worked loose, has become unsoldered from the terminal lug, or your coax has come unsoldered from the center pin. All of these things would really honk up your SWR, or Standing Wave Ratio, which is sort of like a string on a guitar that is tuned to a specific frequency for a specific note. The center freq of the CB band is 27.155 Mhz, so you would typically "tune" your antenna for that to be the lowest. A firestick KW is not tunable, so that should not be an issue. Look to your coax at both ends, and the coax itself to find your problem. If you have a simple ohm meter it would help to locate the short circuit. Good luck, write back if you need some assistance in further troubleshooting.

There may be an issue with the coax, antenna, connections, settings or a combination of them all.

Set the radio to AM, a channel of your choice, volume to just under 1/2 way, squelch to off or fully CCW. Make there is no plug in the ext speaker jack. If there is still no sound, try connecting an external speaker and try again.

Carefully check all connections for tightness and inspect the coax cable for evidence of being crushed, pinched, cut and jacket damage that could allow water to enter. Replace the coax cable if any of the mentioned problems are found.

Inspect the point that the antenna is connected to the mount / coax cable. It is not unusual for this area to become oxidized due to exposure to weather. Thoroughly clean or replace parts that can not be cleaned up.

Check the antenna for damage. If "higher than rated power" has been introduced to the antenna, it has likely failed, and will require replacement. Since CB is limited to 4W AM and 12W SSB, most antennas are rated for 25W or less.

You should obtain and connect an SWR meter with a short length of coax cable between the radio and the antenna. The meter should be rated for the frequency range of the transmitter - in this case, HF or 27Mhz (11 meters). Tune the antenna for lowest SWR over the range of frequencies by physically lengthening or shortening the whip in the base in 1/8" increments.

I hope this helps!

If antenna optimization didn't work you'll probably have to move.