Common UHF problems

[taslucas]

This is ok"-

3db for the terrain im in (possibly with a 4.5 interchangeable whip). So look for 3dbd
Around 600-800mm tall to help help clear the roof line from the bullbar mount.
Stainless steel as opposed to fibreglass to help with tree strikes. (perhaps with one of those lock pins in the spring).
A ground plain independent.
Nice thick heavy duty/good quality coaxial cable. - Mobile Antenna cables normally come with fitted with rg58 - thin cable. Thicker cable = different connectors to suit

Only use Omni antennas for vehicles - directional antennas are used for base sites ( when you need extra coverage or reduced coverage in a particular area)

Im looking at something in the GME range, do you have any suggestions?

I think the aerial i got the first time may be a directional one. Would that create the problems im having?

[TPC]

Would RG6 quad shield coax used for TV installs be suitable for use?

TV coax is 75 ohms and not suitable for CB's, you will be ok with good quality RG58, the loss will be minimal over a short length.

Im looking at something in the GME range, do you have any suggestions?

I think the aerial i got the first time may be a directional one. Would that create the problems im having?

I would be surprised if the antenna you had was directional, mobile whip antennas are usually omnidirectional.

[GQ TANK]

Agreed don't use the 75 ohm cable. Mobile antennas are mainly designed for use with rg58. If you where running 15 or more metres of rg58 then it would be an issue.

All the new gme radios have the same spec - it depends on where and how you want to install it.

Im still running an old tx3400 40 channel unit - and don't plan on upgrading at the moment.

Im not sure if you have mentioned what your problem is.

You have asked if transmitting without a antenna will cause a problem (it can blow the RF power amp)

[Clunk]

we use to sell mobile yagis that were connected via RG6 but this was to receive RF signals, so probably a different kettle of fish.

[taslucas]

Im not sure if you have mentioned what your problem is.

You have asked if transmitting without a antenna will cause a problem (it can blow the RF power amp)

Yeah I was wondering how you would tell if there was damaged caused by using my uhf with the aerial disconnected.
Also had these problems with reception:

I did notice the cable had come out of the back once a while ago but im not sure if i used it like that or not.

I tried to use it last weekend and i could hear and talk if the other car was very close (like 15 metres) but not any further away. The other vehicles say that im very distorted.

In open area i could hear the odd bit from the others up to 100 metres away but they couldnt hear nothing from me.....

[GQ TANK]

If you have no antenna it will affect the receive and transmit.

The only way to tell if the rig is ok is to test it with a service monitor.

You could try it with another antenna and see if you have range - and can be heard from a distance.

Mobile yagi - a yagi is a bit like a spot light - you put it in the direction you want to like up. QA mobile mounted on the vehicle will give better gain in one direction - but behind it there will be a null. I use yagis with my coms trailers when Im running low power and linking to another site. I have also used a handheld yagi for dfing (RF direction finding)

[Bacho86]

Hi Lucas,
If you have transmitted without an antenna you may have damaged the transmitters output amplifier, most modern radios can cope with transmitting without an antenna for short periods without damage. If you have damaged the radio you should still be able to receive ok but only be able to transmit for a short distance, if you are also having trouble receiving that sounds like a faulty antenna or cable.

Well after having some issues with people hearing me on the uhf radio last trip, I think I've nailed down the issue based on the above description.

My antenna is not normally installed, and likely kids have been playing and pretending to use it and possibly " fried it as a result
@taslucus what was the outcome with your radio, did you have any luck getting it repaired?

Otherwise I maybe up for a replacement radio, good excuse to upgrade to 80 ch I guess, any recommendations on what to buy? Would be good to stick with gme as I should be able to reuse existing wiring



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