Getting better UHF range

[Canyonero 4x4]

I have recently installed a brand new Uniden UH088 Sundowner and hooked it up to the existing cable and aerial that was on the truck when I bought it. I am 90% sure it had a blue tip, but that got caught on a tree and has been missing for some time, so I put some blue heat shrink over the tip to protect it from the elements.
But I don't get much range. We'll have 6 cars in a line talking to each other but I'll only hear half the conversation. Eg. Car 1 can talk to Car 6 fine, I'll be car 4 and can hear car 6 fine but I won't hear car 1 at all. What can I do to improve this.
Is it possible it's not a UHF aerial? The car came with 2 aerials. One short, one tall, both with what I believe to be blue tips. The shorter one snapped so I can't try that.

[macca81]

tip colour doesnt mean squat. and its fine if its not on there, its only to stop it hurting so much when you poke yourself in the eye...


where have you mounted the arial and are all your conections good?

[festy]

Yes - it's quite possible it's not a UHF antenna.
I assume it's a fibreglass helical whip? They're usually black, with a fibreglass center, and a copper wire wound around in a spiral pattern.

How long is the antenna?
Where is it mounted?
You can do a few basic checks with a multimeter to see if your coax and connectors are ok - unscrew the connector from the back of the set, and check the resistance between the center pin and the outer body of the plug - they should be open circuit.
Remove the antenna, and short the antenna screw mount to the vehicle's body, then measure the resistance again - there should be no resistance (closed circuit)
If those checks are ok, your coax is probably ok.
You can also check by turning your squelch down, then unscrewing the antenna lead from the back of the radio. If the static gets louder when you remove the plug, you've got a problem.

I'm not far from Camden if you need a hand sorting it out.

[gp339gm339]

Trace the cable, make sure there are no kinks (squashed) or some has extended the cable by twisting two bits together. (To extend rf cables the correct type of connectors must be used)

Have a good look a the connector, I have repaired heaps of radios faults in the past due to people using the crapy screw together RF connectors from dick smith.

If your not sure about the antenna / cable you can buy complete antenna kits including cable connector and antenna

NotE:- depending on the type of antenna being used, there will be a short at the antenna,