2 way radio communication

[terravistawombat]

Hi
I am interested in hearing opinions on 2 way radios preferences for general safety and road condition use, and for comms between a number of vehicles on a trip.
I've seen recomendations for 27 MHz, 29 MHz, 40 channel CB's etc.
Does anyone have knowledge on which system is the best to look at?
Thanks
Ian

[geeves]

As a general rule the best is the same as the people you want to talk to are already useing. 40 chan uhf cb also known as prs is very good for line of sight and close range ie convoys etc but will let you down if there is a hill in the way. HF and vhf give good range but not as clear and prone to noise and can become completly unintelligable if you are very close.

[blackpumkin]

A good 40 channel uhf is great, most people have them which also helps a 6db airel is the norm but if there are a lot of hills use a stiff 9db airel, 9 db airels work better if the trucks is parked..

[Vineboy]

Go the UHF setups. I have a uhf at home with a monster antenna and my wife can reach me 30ks away. Aerial type and location on vechicle VERY important. Big is not always better

[terravistawombat]

Thanks for the advice.
UHF sounds good to me.
Cheers
Ian

[dasnoboarder]

Another thing;

Where would be the best place to fit the antenna? Bullbar? Spare tyre mount? Other?

[geeves]

Theres a whole science around antenna esspecialy high gain ones.
For most the best place is the middle of the roof as they require a large flat ground plane but this isnt such a good idea in a forest. Some ariels dont require this ground plane so can be mounted on the bull bar.
My vhf is mounted on the bull bar my uhf is handheld so sits in a cell phone cradle in the front window. Both work ok

[terravistawombat]

I had a talk to a local radio specialist, and he said that the antenna position is nowhere near as critical as it was a few years ago.
Although central roof is ideal, the possible damage from overhanging trees. low bridges , or rolling the vehicle etc far outweighs the small loss of signal integrity from bullbar or mudguard placement
He also commented that high gain is highly recommended, as well as a spring base antenna rather than semi rigid fibreglass.
He highly recommends a 4.5 to 6 db antenna for general purpose. He claims that any higher db rating affects the way the signals are received or sent as the UHF signal radiates perpendicular to the antenna. Taller and higher db antennas can effectively reduce the abilityof transmissions unless in wide open no hill areas.
This may also be a load of crap he told me, but he has tried to talk me into a cheaper alternative, which makes it sound genuine.
Cheers
Ian

[caffa]

terravistawombat said:

I had a talk to a local radio specialist, and he said that the antenna position is nowhere near as critical as it was a few years ago.
Although central roof is ideal, the possible damage from overhanging trees. low bridges , or rolling the vehicle etc far outweighs the small loss of signal integrity from bullbar or mudguard placement
He also commented that high gain is highly recommended, as well as a spring base antenna rather than semi rigid fibreglass.
He highly recommends a 4.5 to 6 db antenna for general purpose. He claims that any higher db rating affects the way the signals are received or sent as the UHF signal radiates perpendicular to the antenna. Taller and higher db antennas can effectively reduce the abilityof transmissions unless in wide open no hill areas.
This may also be a load of crap he told me, but he has tried to talk me into a cheaper alternative, which makes it sound genuine.
Cheers
Ian

He's pretty much on the money Ian. Around town, antenna and other apparent modulation enhancing ad-ons are a waste of time and can be detrimental to tx and rx . 4.5-6.0 db gain is a standard aerial and you can better this a little with certain spring bases. Not sure about him but if I was in a roll over, the last thing on my mind would be where my aerial was mounted. I have proven that the best spot for an aerial is still in the middle of the roof. That being said, I have no aerials in my roof at all. The difference wasnt worth me boring a hole in my turret. If you dont have a bullbar you can get z-brackets from Dick Smith in Beenleigh for around 10 bucks. This will enable to you mount your aerial from under a bonnet etc. I actually like z-brackets but they do take their toll on paint with scraping on the bonnet after time and take things back to bare metal around the areas where they rub.

In response to your original question, my opinion, for what its worth, is to go with a standard 40 channel uhf setup with a spring base and a good quality antenna. I live about 20 minutes south of you and these are the most popular nowadays. Channel 40 is where you find your road conditions etc, channel 5 is the emergency repeater and most all the trucks use channel 26 on the M1 when travelling the coast road changing from channel 26 around Yatala northbound and to channel 26 around Springwood southbound. For this, a scan function can be handy. I mainly use channel 40 on the M1 as you get more info off there than you do on 26. I hear very little from my 27meg radio nowadays and if I didnt own one, couldnt justify the expense in purchasing one. I have a feeling though, they are going to come back in for the exact reason ppl started going to uhf. Many moons ago, ppl started to go the way of uhf to get away from the wankers on AM. uhf always had heaps of advantages over AM but general population never really cared because they got what they wanted out of AM which was close range chat and communication. Now that uhf has come down in price and it too is full of wankers ½ the time, I reckon ppl for club trips or closed trips will start using AM again so they can have some privacy ... I guess time will tell though ... lol AM, or 27meg is very cheap nowadays but it would take a lot of looking to go past uhf still. if you only want close communication, you may consider a handheld uhf. These transceivers are generally 1watt output but receive like any other radio, limited only by their antenna. We have trucks run Gold Coast to Cairns using 1watt handhelds without incident. It lets them hear whats happening in their greater area and lets them talk to ppl close, real close to them. I personally wouldnt have a handheld for primary communication as you would be in trouble if you were stuck somewhere and only had a handheld to try and get help with. Most radios you buy in the shops have a 5watt tx capacity. If you decide you need more, there are other options available that have more tx power.

[terravistawombat]

Thanks muchly for the info, I have now bought a GME TX 3200 UHF 40 channel, which seems to be a popular choice.
Cheers
Ian