Uhf issues

[Makka]

Do you have the unit connected to the cigarette live wire? If so, hook it up to your deep cycle battery directly. I use to have it this way and found that the accelerator / idling from motor was inteferring with the unit when listening. Just a thought.

you should run it from a point in your fuse box. the only reason you would get interferance is bad earth

[macca]

Oh well. must be just me then.....

I had a 80 channel and couldn't be heard by the 40 channel radios unless I put the mic close (less than 50mm) to my mouth, got fed up with it and had the old 40 repaired then reinstalled it in the car.

Spoke to a GME rep and he said it was a problem and there is no fix for it.

Kat, it's not just you.

[LostBenji]

It wont be the differance betwen the 40 / 80 channel rigs as long as they are on the same channel. (and between channels 1 - 40)
40 - channel reciveing a transmission from an 80 channel - the recived audio is lower
80 - channel reciveing a transmission from an 40 channel - the recived audio is higher, worst case you could get some audio blocking (bit of no audio). But most of the cbs are desiggned to prevent this.

Correct.

actully there is a differance the older 40 channel radio's are wide band and the 80's are narrow band if the recive or transmit is not intune it can cause this also sometimes if you are to close to each other it can cause this i have had it happen a few time at work....

GQ was correct and on the money. 25KHz Vs 12.5KHz channel spacings, deviations halved result in exactly what he said. Now somebody transmitting on Channels 79 or 80 nearby the troubled radio that could be an old 40 (Full DIN size is likely an 80ch radio) would see possible issues, not likely here.

you should run it from a point in your fuse box. the only reason you would get interferance is bad earth

Incorrect, noise can come from anything such as bad radio front-end, bad antenna, loose fittings, corrosion on the fittings, hot-dry air blowing over antenna, poorly mounted antenna and location, etc. etc. Common issues seen now are bad/noisy electrical devices in the vehicle like cheap phone or USB chargers, cheap mains inverters or even in some cases, failed alternator diode. An AM guy who has been playing with radios since the 70's should know this....

[bazzaboy]

As suggested, it could be a number of issues, inducing noise interference, bad earth or power connection, frequency bleed ( this sometimes happens if a 80 channel & a 40 channel are in close proximity ), or something as simple as a dry joint on the mic. I would open the mic ( carefully if your not competent, or have a tech do it ), check for a dry joint and clean with a good contact cleaner. If nothing comes from these checks, put in in for a check-up.

[LostBenji]

I forgot to mention above, if the radio fails to shutup, take it to tech to get fixed. Ask them to check the PIN DIODE

[Makka]

Correct.

GQ was correct and on the money. 25KHz Vs 12.5KHz channel spacings, deviations halved result in exactly what he said. Now somebody transmitting on Channels 79 or 80 nearby the troubled radio that could be an old 40 (Full DIN size is likely an 80ch radio) would see possible issues, not likely here.

Incorrect, noise can come from anything such as bad radio front-end, bad antenna, loose fittings, corrosion on the fittings, hot-dry air blowing over antenna, poorly mounted antenna and location, etc. etc. Common issues seen now are bad/noisy electrical devices in the vehicle like cheap phone or USB chargers, cheap mains inverters or even in some cases, failed alternator diode. An AM guy who has been playing with radios since the 70's should know this....

These days with better electronics and manufacturing this is not as bad as in the dark old days of HF with crystal phazing ..... with the way IC's are now it is not as bad as it was .......the old truck i was in had a 40 and never had a issue talking truck to truck or through repeaters the new truck i have a lot of people have issue hearing me especially when close together been through every thing makeing sure that all joint are good and there is no corrosion . i dont have issue talking to other 80 ch radio users only people with the 40 ...... and only sometimes as i stated if the wide band radio is out of tune slideing of frequency the narrow band radio will get the carrier but not the modulation... yes there are other factors but this is the main reason .....

[Bush Ranger]

you should run it from a point in your fuse box. the only reason you would get interferance is bad earth

Earthing is good in the vehicle.

[Makka]

how is the condition of the coax no nicks water in the coax is bad to as well as corrosion on the antenna base where the antenna attaches

[threedogs]

Earthing is good in the vehicle.

I ran an extra earth wire from the base of my UHF antenna to the earth
my start battery. Reason was the powder coating on the bullbar prevented a good earth.
The less joins in the coax the better, lol

[Bush Ranger]

I remember the same thing happening with a vehicle I had years ago with a CB connected to the cigarette lighter live wire and was told to put an inline resistor to help the problem, which it did a little bit. It has some thing to do with the way the cig lighter live wire is set up which attracts the noise I`ve been told and I hooked it up through the ignition some how after that, so the CB would only come on when the ignition was on accessories. I took the same option when fitting the UHF to the wagon and forgotten about the problem from years ago, that is why I put an inline fuse to the deep cycle battery, due to it being an easier option to do.