Thread: commercial uhf or not..

You will not be able to licence the 25w, and in any case it will provide little if any extra benefit - since UHF is pretty much line of sight, all increasing the power does is enables you to talk over the top of other users who respect the 5w restriction. The extra power will in some circumstances get you a little bit of extra coverage by forward scatter, but it won't amount to much. I suggest that it is not worth the extra money.

John

Originally Posted by JDNSW

You will not be able to licence the 25w, and in any case it will provide little if any extra benefit - since UHF is pretty much line of sight, all increasing the power does is enables you to talk over the top of other users who respect the 5w restriction. The extra power will in some circumstances get you a little bit of extra coverage by forward scatter, but it won't amount to much. I suggest that it is not worth the extra money.

John

what did you mean by this (im new to this), i know its not legal for non commercial frequencies, however i was thinking if i ran at it 5w and in case of emergency and emergency only i needed to use the extra power (although it sounds like it wouldnt add up to much extra coverage) its a risk i would be willing to take (pretty much like some people i know with marine VHF without being licensed, they dont use them other than to listen but if they are in trouble they would use them and not care about the consequences!)

Thanks

Steve

I bought an Icom in 5w/15w/55w selectable output, I only run it at 5w, but am happy knowing that i can crank it up if i ever got stuck (big risk in a freelander lol). In flat(ish) country it will travel alot further, and in transmission atleast, makes up for my shorter antenna (45cm). Ive been once in convoy and swapped over to 55W requesting updates from vehicles that had become separated, only to have them phone me, so im happy.

I realise its not for daily use, and i realise its close to line-of-sight, but im happier with it.

The decision is yours. Just make is respectfully, Ie dont use 25W unless its neccessary, dont overtransmit people, etc.

cheers!

Originally Posted by 5teve

which one would you recommend?

Hi Steve

All the rules are here:

ACMA - Citizen Band Radio Stations

Australian CB radio operates on what they call a "class license". In short you don't get a callsign or have to pay any money, but you do have to stick to the rules. (Located on the ACMA website.)

5 watts ouput is the standard on UHF. Having said that, if you're not annoying anyone and don't use it much around town, it's probably doubtful you'd ever get caught using a commercial unit with a larger output.

What most people forget is a greater output is no good if you can't hear the other person..ie It doesn't mean you can receive weak signals.

It is far better to spend some money on a good antenna. There is a wonderful thing called antenna "gain". Simply meaning, a good quality antenna with a higher "db gain" will multiply your effective transmitted signal and also help recieve weaker signal. I cannot stress this enough - A well tuned antenna, fitted correctly is the way to go. This may cost you another couple of hundred above the cost of your CB, but well worth the money. Once fitted, the Antenna must then be tuned for correct VSWR. (colloquially called "swering the antenna")

I have ventured off road in Victoria’s high country (notorious for losing UHF signals in the many valleys and hills) Each of us in the convoy had different equipment - the best signal was from the standard uhf cb with a good antenna.

The GME is a solid unit and there are a few others too.

If you really want high power consider a Amateur Radio license, they are much easier to obtain now (no longer need Morse code) and they have a "Foundation" license which is pretty straightforward to get too.

I support all that has been said as to antenna tuning and the 5w limit. You need to hear the other party.

Don't forget to get the antenna installed in a good radio location on the vehicle. This may not be the best to suit you visually though, or for negotiating overhanging branches.

Maybe you need a shortish one (45cm colinear - two section pre-tuned one above the other with a twisted coil in the middle), (as against a 1/4 wave straight whip that has no gain) on the bull bar, but then a ground independant type with some real gain, and therefore of multiple sections, able to be plug changed over, mounted up high - roof or rack.

This would give you max legal range when out in the backblocks but also can be removed when not required, leaving you with the bullbar job for everyday use.

Either way, get it done by a techo with the gear for checking the cables/location/mount.

The 25W jobs are for those who use commercial frequencies that are nearby, who pay for the license and the right to use those frequencies.

Amateurs also have licences and can operate on several frequencies allocated to them. They sit exams, pay money and enjoy good comms. Their systems can get them talking around the world.

The new study path they have to "get on air" is really easy compared to that of just a few years ago. Most can get their Foundatrion Licence in a weekend or over just a few weeknights.
Look up the local affiliated clubs on the WIA site, for a club near you.

Rovers 4

Just to add to and agree with the comments already mentioned, don't bother paying extra for a set which can do extra power. I have an iCom (Bought for a different reason) and although I have the programming lead and software, the power is still set at 5w. Spend the money on the aerial and getting it fitted properly with good cable and connections. A high gain aerial is worth far more than an extra 20w on what is a line-of-sight frequency anyway.

Thanks for the Info there guys... im aware about the importance of the antenna, im just going through this with the marine radio i have, we have tested the antenna with an swr meter and its very very poor at best! there is no way of tuning it either :O( we arent too sure if the swr meter is out tho.. so we are just building a dummy load to calibrate it.

i was mainly enquiring about the extra power due my curiosity about how much extra distance i would get.. and it sounds like it depends.. sometimes it can others it wont.. and i thought the ability to run at 5w but have say 25w or 50w on hand in emergency would of been handy..

is the amateur radio license the same as the marine vhf license? im wondering if i could combine the 2? they probably arent too far off the same!

again thanks for the info.. as per usual you are all incredibly helpful!

Steve

Steve,

The power distance ratio is logarithmic therefore double the pwr does not double the range. (So a rough estimate would be 25watts should be roughly double the range of 5 watts maybe a little more). But it still can't penetrate hills Maybe on your boat or in the desert or on top of a hill it would be significant but proabably negligble difference elsewhere.

Amateur radio VHF operates at around 144-148Mhz and is a bit lower freq. than your Marine VHF which, from memory, is around the 160Mhz mark (?).
You may get a radio that operates on both freq.s but it would be a compromise and you'd have trouble tuning the antenna for both freq.s.

An amateur radio licence limits you to only talking to other amateurs only on amateur bands. More info on the ACMA website or at The Wireless Insitute of Australia. The new Foundation Licences are an entry level Amateur licence and can obtain with weekend course in regulations etc. (Contact WIA if your interested).

I have found many “Hams” that are also 4wders the two hobbies tend to complement each other. (They both drain your wallet too) although sounds like you have a boat for that wallet-draining-experience

Having said all that, I still run a UHF CB for close vehicle operation , as that is what most others are running. (Also have a couple of those cheap Chinese hand held uhf cb's which are handy for recovery ops, kids and campground comms. )