Cb coax extension

Sorry, it worked fine but can't comment on how much the signal was attenuated.

Hi Notso,

Yes you can run the coax over that distance for a base station mounted UHF Radio, but not the standard coax that you get when you buy a standard vehicle mounted antenna. You would have used the coax that is around three times the diameter and designed to be used over long runs.



Cheers


Stephen

I would prefer to keep the cable around the 5mm size, 12mm holes are a bit much and obviously the bending radius on the smaller cable would be much smaller. What length (ball park) do you think I could go out to keeping the cable diameter the same as it is? It is for a UHF. I might be able to move the head unit towards the rear slightly to gain some extra length.
Tim

I just installed a Uniden 5W UHF in the BT50. Antenna cable run was 5m. I had it tested. SWR was ideal at 1:1. Measured output was 3.5 watt. I was told the loss of output power is as much due to the quality of the radio as it is cable run.

Me, I dunno, just quoting what I was told by one who knows a lot more than I do. (Runs a comms shop and is a ham radio freak, so I figure he knows a bit of what he is talking about.)

Cheers

Tim,

It's up to you, but 9 meters is approx. 30 feet and that is a long run of RG-58 for UHF. The closer you can get the radio to the antenna the better so as to keep the coax cable as short as possible.

With a 9 metre run you could loose around (+ or -) 1 watt of output power from the rig. Make sure you check/retune the antenna for the lowest VSWR you can get.

Cheers P&J

Quote "I just installed a Uniden 5W UHF in the BT50. Antenna cable run was 5m. I had it tested. SWR was ideal at 1:1. Measured output was 3.5 watt. I was told the loss of output power is as much due to the quality of the radio as it is cable run."

What was the meter that was used to measure the power output and where was the measurement made? Something like a Uniden should put out its full 5 W rated power. The power meter will be as much of the problem as the CB radio. You will also suffer some power loss from the cables, the connectors are likely to add a dB of loss.

Peter,

Thanks, I was hoping to get some input into this. But I can't help much - I don't know the brand of the meter or anything like that, or its calibration, or if indeed the test was done correctly. I have no knowledge in this area apart from some googling last night and must accept the advice I am given.

The measurement was made at the back of the radio with a patch lead only a few inches long.

I, too, thought that Uniden was a good brand and expected it to deliver nearly all of its advertised 5 watts. 3.5 was a bit of a disappointment.

However, I read somewhere (maybe here!) that if the SWR figure is good (which mine was), 3.5 watts vs 5 watts won't make much difference to range. To my simple mind that does not equate, but if that's what the experts say, I will accept it.

I might try to get a second opinion just to see if different test equipment makes a difference.

Cheers

Hi Boobook,

Thanks for the info on the (possibly new) LL195 coax. To me the double shielding is the way to go for HF and short runs on UHF.

I have enough coax to see me out, but it's very handy to know about the LL195, at a very reasonable price as well.

Cheers P&J