UHF and aerial....what do you have?

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Maarten
Maarten (DUTCHD)
23 Jan 2017

Hi all,

This weekend I was told my radio was "shit".... previous trip it had seemed ok but it was in flatter terrain. Currently i have a cheap Uniden 40 channel (purchased second hand) and the GME aerial that was already on the car. 

 

Now I'm looking at remote mic GME units and a GME aerial. Especially in the aerial department, there's a bit of choice but I have no idea what the differences are and whats suited best to high country terrain... 

What do you guys have and what would be a good unit/aerial to purchase?

Thanks,

Dutchy

Matthew
Matthew (discomatt)
24 Jan 2017

There are high gain and low gain aerials, from memory for travelling mountain terrain in convoy low gain is what you want, for travelling flatter desert type terrain ahd wanting longer distance high gain is the best. It all has to do with how the signal is transmitted and nothing to do with size. Mine is low gain.

I would check all the wireing connections and earthing before rushing out and buying anything, you only need a slightly loose or faulty connection and the signal goes to crap

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(Yarra_Ranger)
24 Jan 2017

Damn I hate agreeing with Mattsurprise

But yeah, check the connections first. Someone I know had a twisted together aerial joint and it went poop. after soldering it was fine.

For hilly terrain get a short antenna.

Have a look at these,

https://www.4wdtrip.com.au/offroad/social/forum/read.aspx?originalpostid=5293&forumid=4

 

https://www.4wdtrip.com.au/offroad/social/forum/read.aspx?originalpostid=4906&forumid=4

 

I use this antenna http://www.gadgetcity.com.au/gme-15cm-ae4002--2.1db-fibreglass-small-antenna-whip-p-2829.html

When it's mounted on the base it gives around 3db.

 

Some here may know Jim, he did a video explaining some of it too.

https://www.youtube.com/watch?v=2frSoyTGK_A

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Hi Dutchy

We have a GME unit with remote mike similar to the one you are considering, has worked well for 6 years. Just don't trust the shitty spiral wire antenna they sometimes provide. Ours lasted less than 500 km on dirt roads, the constant vibration snapped it off and it flew away. Paid top dollar for one of the black fibreglass ones in Weipa, and haven't looked back. I'm told that for hilly terrain, a short (around 15 cm ) antenna is better. Sounds counterintuitive to me, but that's what it said on the pack  - I haven't tried it, but I do keep it as a spare which fits in the glovebox!

Cheers

Mike

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Check all connections if you do not have a SWR meter to check you antenna being in swr, then un screw the connector on the back of the radio and also remove the aerial, then test the coax with a multimeter for a short in the cable or connections. If there is a short in the cable then it will need to be found and have the plug or aerrial end re-solderd or the cable replaced. If this all checks out you can also plug your uhf into a known working set up on another car and check it as well. As for aerials yes the above two are correct, the lower the gain the better it is in mountain hilly terrain and the higher gain on flatter ground. As for radio's i never run retail radios such as gme, uniden and certainly never oricom or other cheap radios. If you are looking for a radio that will be basically bullet proof, Find a commercial radio that is programable to suit your needs such as a Simoco SRM9000 or PRM80 Phillips. I am currently running a Motorola Spectra with 130 watts output with a GME Heavy duty spring base 6DBI Elevated feed with a stainless steel aerial. I find this aerial for recieve to be a very good all rounder. There are others that make the same style aerial my other choice would be a RFI branded one. Please just do both your self and every one else a favour and dont buy a orricom or other cheap arse branded ebay UHF radio. You can buy a ex-commercial radio cheaper then you can most retail branded stuff

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(Yarra_Ranger)
24 Jan 2017

Check all connections if you do not have a SWR meter to check you antenna being in swr, then un screw the connector on the back of the radio and also remove the aerial, then test the coax with a multimeter for a short in the cable or connection......

http://uhfcb.com.au/Frequently-Asked-Questions.php

 

Well that's marvellous advice, without a licence you are only allowed 5 watt output not  130 watt.

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Mark
Mark (markcc)
24 Jan 2017

I'm no expert, but from what I've read, 40 channel units are now superseded and 80 channel is the "norm". 

80 channel units run on a slightly different frequency to 40 channel units; sorry for the poor explanation, hence they sound "distant" if one type is communicating with the other.

You may find a better explanation asking Google.

Hope this helps you slightly.

Reply

http://uhfcb.com.au/Frequently-Asked-Questions.php

 

Well that's marvellous advice, without a licence you are only allowed 5 watt output not  130 watt.

that is also correctand in the near future all 40channel uhfs will also be non compliant radios as well. I am sure that many will not worry about it until there one needs to be replaced. The radio i run can be turned down by a flick of a switch i normally only run about 25watts not the full 130. Just so you also know that even having a licence such as a ham licence does not allow you run any more power on the cb bands. The thing i s that you can turn the commercial radios down to 5 watts of power if you want to as well. I simply only stated what radio and power i run

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I'm no expert, but from what I've read, 40 channel units are now superseded and 80 channel is the "norm". 

80 channel units run on a slightly different frequency to 40 channel units; sorry for the poor explanat......

this is right. They virtually have the first 40 channels as they were and then crammed the extra 40 channels in between them on a different frequency spacing of 12.5khz.  Its called narrow band now and to avoid the interference between channels they reduce the modulation deviation on the narrow band radio's, hence leaving the older wide band sounding quite and distant. Something i have forgotten as i still set my radio's up when i programme the channels in to have the first 40 channels as wide band and the next 40 in as narrow band

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Lyndsay
Lyndsay (Wally068)
24 Jan 2017

Like the others have said check your connection as a quick check, but i would look to replace it with an 80 channel. Keep in mind 5w is the only legal radio you are allowed to operate, and radios that are capable of doing more than that but can be switched down to 5w are still illegal. Chances are your antenna is ok if it is a GME but if you wanted to change that as well i would look at a 6.5db feed choke style.

Cheers

Lyndsay

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Jim
Jim (JimMc)
25 Jan 2017

 

Hi I put a youtub video up some time ago about antennas and hear the link I hope it helps you out

https://www.youtube.com/watch?v=2frSoyTGK_A

Antennas.
Choosing the right UHF CB antenna and phone antenna for 4x4ing is important, as more powerful antennas can broadcast signals further and clearer.
However a lower gain or less powerful antenna can broadcast better in hilly terrain, as the angle of the aerial matters less. Lower gain antennas are 3db or lower, for distance over flat terrain a 6db UHF CB (ultra high frequency) antenna or higher will suit better.
Even with a lower gain aerial/antenna it still won't guarantee the signal will be carried 100% clear over a hill.
Hills and buildings can still weaken signals but a lower gain antenna will increase the chance of carrying a full clear signal beyond any obstacles.

 

Regards Jim

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(Gazza)
25 Jan 2017

I run a cheap and nasty oricom for a number of years, never let me down yet, except once , when my handbrake ripped the mic wires out, my fault, just resolderd the wires back.

 

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(Yarra_Ranger)
25 Jan 2017

(Gazza) wrote:

I run a cheap and nasty oricom for a number of years, never let me down yet, except once , when my handbrake ripped the mic wires out, my fault, just resolderd the wires back.

 

Yes I always hear you loud and clear Garry.

Reply

Yes I always hear you loud and clear Garry.

I'm running a cheap Crystal 80 channel with a mysterious gain white fibreglass aerial, and have had no complaints. I was running a 40 ch Uniden in my Navara but it shorted out when I drowned the car with the same aerial. It work great for range on the freeway and just as great over hills in the bush. Hwy range around 10km that I know of so far, during the day.

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Yeah i have a 2dbi and 6dbi set up, running off a gme unit. So far no issues. Connection and reception is quiet good.

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