UHF troubleshooting

[Rocker]

Hi all,

I'm trying to work out of my UHF is working correctly, the trick is I don't have a second unit to test with or a mate with one that I know of, so I'm left with trying to work it out from random signals and trying to radio check with people that are who knows where.

I live in a metro area where it's not likely to have many people on UHF and with buildings etc. is far from ideal for it anyway. The radio is an old 5W Uniden mounted unit, with what I think is a 2.1db antenna. Previously all was working fine and it's been sitting in a box for the last 5-6 years.

My transmitting seems to be ok. I've tried random radio checks and gotten replies back, but they're so hard to make out. A fragmented bits have said 'loud' and 'clear' so I think it's actually working right, but I had real trouble hearing them through the static and breakup.

I suppose this could be because I'm transmitting on a 5w and if they were on a 2w or whatever they would receive me fine but possibly be too far to transmit back? Could that be right?

I wondered if perhaps I was having trouble receiving, but on occasion I do get a clear, loud message so then that tells me it's working.

Maybe I'm just wasting my time trying to test with randoms from the city?

[happyhunter]

Is your Uniden 40 channels? Read this: http://uhfcb.com.au/UHF-CB-Changes.php

It should still work but there may be issues bleeding on to other channels. When you get a radio check, ask which suburb the other station is located to get an idea of the distance.

UHF radios are so cheap these days it's probably easier just to buy a new 80 channel unit.

[Supaduke]

Make sure your antenna has a good earth. In metro areas channel 40 should have plenty of traffic to check your signal.

[Rocker]

Happy. 40 channel radio and you can enable up to 80, it will listen on the additional 40 only but not transmit. I know a new UHF isn't a fortune, just since I have this one here and it worked fine before I wouldn't just straight to replacing it just for the sake of it.

Supaduke. The antenna is mounted on the usual bullbar mount. The bullbar is painted, just a steel washer top and bottom of it, maybe the pain is killing the ground?

[pete1]

Like Supaduke said 40 should have plenty of traffic as all the trucks use it and they have big antennas so should get a reply. You should have a adjustment to get rid of static if you haven't used it already

[Supaduke]

The squelch dial is just a filter to set how strong a signal needs to be before it comes through the speaker. Ideally you dial it down till you get static then dial it up just enough to cut out the static. All modern in dash units are 5w, the permitted maximum for civilian units. Although ham radio enthusiasts can get access to 25w boosters (technically illegal though)

Generally only hand held units are 2w to conserve battery life.

With Aerials as a general rule the shorter they are the shorter the range but the better they are in non line of sight situations. Short Aerials work best in mountainous terrain where point to point distance might not be that great but there are large mountains between you. Long Aerials give excellent range but only work in flatter terrain. The common compromise is a 6db aerial.

Depending on what sort of finish you have on your bullbar it could be affecting your earth. It's works to some degree so it's obviously conductive to some capacity but removing a small patch of paint to give proper metal to metal contact may help.

Check all your fittings, make sure no stray bits of copper wire are poking out and touching metal. It's important the inner and outer wire on an antenna coaxial doesnt touch. Check there are no splits, cracks or excessive kinks in all your cables.

[on_one_wheel]

The biggest problem you will have with a 40 ch uhf is that they are not perfectly compatible with the new narrow band 80 ch uhf.

You will have people with 80 ch radios telling you that you sound scratchy and visa versa.
You will especially have issues receiving the narrow band 80 signals with your 40.

The 40 ch can actually interfere with the 80, that is is why the 40 is being phased out and will soon become illegal to use.