Ham Radio Mississippi

CB Radio

[Today’s run: 3.9 miles in Starkville]

This afternoon I was over helping my neighbor with his big rig. He had told me quite awhile ago that his CB radio was not working well at all.

He had the antenna sloping rearward from the top of his passenger side mirror. I suggested he straighten that up. Also that he look over his feed line.

Time had passed and he mentioned the CB again so I told him we could check it out this weekend. So we did that.

This afternoon I gathered up my stuff and we looked things over. The feedline looked ok. It is routed out through the door. But he rarely uses that door and the line looks good and stout, not damaged.

The sloping issue is because he pulls a dump trailer and frequently gets loaded with asphalt from a hopper system which is lower than the usual highway overpass. Not much he can do about that.

I took the antenna off of its mounting bracket and I noticed it was missing a washer that was supposed to electrically insulate the antenna stud from the mounting bracket. There was one, but there are supposed to be two. So the antenna was torqued down on the top of the bracket directly in contact. On the lower side it was insulated, but not on the top side. So the antenna was shorted to the mirror mount bar and probably to the body of the cab. That doesn’t work.

I cobbled up an insulating washer and put some electrical tape on the portion of the screw threads which go through and could touch the mounting bracket. I was much happier with the antenna.

His CB is missing some knobs which also caused a problem. His RF gain I think was set almost completely off. His audio and squelch knobs are coaxial. The missing secondary knob for audio level makes it hard to change the speaker volume without also changing the squelch level such that it is a higher fence for the incoming signals and one hears less. Which means if he is already squelched and he grabs the little stub that is supposed to increase speaker volume, he is likely making his radio less sensitive also.

When all was adjusted we were hearing truckers on the highway which is at least 3 miles away at the closest point.

I attempted to measure his output and I got a reading of 3 watts which seems kind of low (google says the official max is 4 watts). My equipment seemed to indicate the SWR of the antenna isn’t very good. But the antenna seemed to be in good condition and it has no means of adjustment.

I asked him to go ahead and use it all for a bit and see if it works for him.

I’m convinced the antenna and feed line are now working much better. The knob situation probably isn’t going to get better. He may have to buy a new radio.

Also, he said the local “radio guy” passed away and he wanted to know if I would be interested in “tuning up” his unit. I told him I would rather not. With a ham license and being involved in an LPFM, I don’t need to get in trouble with the FCC by messing with CBs. I think repairs would be ok. But a lot of these guys want to get higher output than allowed. And I’m just going to avoid that.

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