Tuning SWR Help needed!

[Navy_FJ]

Help!


I just went to Radio Shack and picked up an SWR meter for the CB. I went out to test it and here is what I found......First I seem to have all the weather bands loud and clear and I can hear numerous people transmitting on different channels. When I plug in the meter I hold down the transmit key and calibrate the meter then I move the switch to SWR and hold the transmit key and every reading is over 3.5 in the red? I am not sure what this means? I have an FJ Cruiser with the bandi mount. I tightened everything down and there are no kinks in the coax. I am confused be cause I am able to hear people on channels so do I just have a bad meter? Thanks for any and all help I am a noob on all this electrical wiring.

Jeremy

[cruiserlarry]

Help!


I just went to Radio Shack and picked up an SWR meter for the CB. I went out to test it and here is what I found......First I seem to have all the weather bands loud and clear and I can hear numerous people transmitting on different channels. When I plug in the meter I hold down the transmit key and calibrate the meter then I move the switch to SWR and hold the transmit key and every reading is over 3.5 in the red? I am not sure what this means? I have an FJ Cruiser with the bandi mount. I tightened everything down and there are no kinks in the coax. I am confused be cause I am able to hear people on channels so do I just have a bad meter? Thanks for any and all help I am a noob on all this electrical wiring.

Jeremy

Weather channels transmit on VHF frequencies, so their reception on your CB is unrelated to the SWR for 11 meter transmission from your radio. Basically, you'll receive the weather channels, probably even w/o the antenna connected.
Similar situation for CB reception - even a bad antenna will allow for reception, but will not allow effective transmission. The in-line SWR meters, like those sold at radio shack, are not always accurate, but should be close.

You don't say what type of antenna you have, but you do need to tune the SWR for the antenna you are using. Firestik antennas are tunable - other antennas require you to shorten/lengthen the actual coax / antenna wire to achieve a good SWR. Make sure you have a good ground on the Bandi mount - this is the most common problem. You must grind away the paint on the underside of the Bandi mount where the antenna stud mounts, and grind away the paint off the FJC door hinge where the nut for the Bandi mount touches. A bad ground will prevent the SWR from reaching acceptable levels, and will cause damage to the CB if you try to transmit. The SWR should be between 1.1 - 2.0 across the entire CB band (it will not be equal across all channels - try to get the lowest SWR near the channels you will use most frequently). Another problem is with excess coax cable - don't wind it up in a neat coil (which creates an inductive field and interferes with transmission), but rather a random bunch and tie strap it. You can also try your meter on someone else's CB to make sure it's working correctly, and make sure all the coax connections are tight.

If after all this, the SWR is still high, try another CB radio and see if your radio is OK....

Good Luck...

[Navy_FJ]

Larry,

Thanks for the help. I went out and resanded all the points just to make sure and then played with the firestik. I had tried to tune it but I did not realize how much the screw will come out on top. I took it all the way out and started tuning it down from there. I have 40 at 1.7 and 19 and below are at 1.2 so it should be good to go. Thanks for the info on the weather channels and a sanity check.
Also thanks to Fj Ollie for the CB set up you have to been my go to guy with comms with out your help and gear I would still be in the stone ages. Now I just need to get outside and pack the truck for Ouray. Watch out for a three year old on CB ch 7 with the handle Cookie monster talking about off roading and watching Dust to Glory on his DVD player in the back.

Thank again.