UHF experts.....Look here
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Aido
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Foxbat
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If the message can be conveyed up or down the line anyway, why would you need the higher output power. There's nothing worse than talking to yourself on the radio not knowing if anyone (or everyone heard you).
Signal propagation comes down to many things and although you may have a 5 watt hand held, in most cases the antenna will let you down every time. To get the best range from the available power, you need a properly matched antenna mounted in the best place on the vehicle. Just because you have a 6dB antenna mounted on the car does not mean you will get the best range in all directions either. The vehicle can act as a reflector (and attenuator) in some directions which will affect range. High output power is not always what is required.
Signal propagation comes down to many things and although you may have a 5 watt hand held, in most cases the antenna will let you down every time. To get the best range from the available power, you need a properly matched antenna mounted in the best place on the vehicle. Just because you have a 6dB antenna mounted on the car does not mean you will get the best range in all directions either. The vehicle can act as a reflector (and attenuator) in some directions which will affect range. High output power is not always what is required.
D21 dualcab Z24 4X4
Member
I would ask you to refraim from using that 50W radio in the bayside suburbs of Melbourne. I nearly always have an fm radio on in the background and you will probably blow the bastard up if you transmit from too close. Ps your neighbours are gunna love it when your doing a radio check in your driveway.
There are three really important factors with UHF radio transmission. Antennae, Antennae, Antennae. Not sure of the facts... Google it.
Most common bases sold these days give you the ability to very quickly change your "whip" to suit your current location. A mate of mine who does this shit for a living has 3 in his vehicle at all times, just quickly changes them as required....... And not that expensive either... And Legal...
There are three really important factors with UHF radio transmission. Antennae, Antennae, Antennae. Not sure of the facts... Google it.
Most common bases sold these days give you the ability to very quickly change your "whip" to suit your current location. A mate of mine who does this shit for a living has 3 in his vehicle at all times, just quickly changes them as required....... And not that expensive either... And Legal...
Aussie Frontier
Member
It all comes down to location and antenna
We used to talk to the states on SSB using old 5watt SSB rigs.
Sometimes more power can make more issues.
The radio wave doesnt travel in a flat straight line.
It curves upwards so sometimes you can talk to someone further away and not get anywhere with someone closer.
We used to talk to the states on SSB using old 5watt SSB rigs.
Sometimes more power can make more issues.
The radio wave doesnt travel in a flat straight line.
It curves upwards so sometimes you can talk to someone further away and not get anywhere with someone closer.
K
Krankin
Guest
It all comes down to location and antenna
We used to talk to the states on SSB using old 5watt SSB rigs.
Sometimes more power can make more issues.
The radio wave doesnt travel in a flat straight line.
It curves upwards so sometimes you can talk to someone further away and not get anywhere with someone closer.
geez, those pics look familiar.
not worth confusing ssb, 27Mhz VHF with 470Mhz UHF.
Totally different beast.
Remember 1 thing, UHF works on 'line of sight', regardless of power output, in the hills/forest high output power means shit.
Though as the pic shows a low db gain aerial will work better in a hilly/forested area, hence why the little handhelds do a good job.
but dont rely on a UHF for an emg radio to save your life in a heavily forested terrain.
And yes with the aid of UHF repeater stations, one's TX/RX can carry for great distances.
Antenna choice is very important on the UHF band, and there is really no one size does all, but my pick for an 'best allrounder' would be a 'raised feed ' type.
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Aido
Member
Ok then lets kick the argument along a little more.
Is 27meg better for group communication? I was always lead to believe that under normal circumstances they were good for 3-7km range irrespective of terrain.
Would never rely on any form of radio for emergency communications in this day and age...EPIRB and Sat phones for extreme remote areas do the job far better. Anybody that fits a UHF "just in case I get into trouble" is kidding themselves.
I relate it to the Fire Brigade responding to cats in trees....How many cat skeletons do you see up suburban trees? Likewise how many 4x4's do you see within cooee of a major town with a skeleton behind the wheel?
Is 27meg better for group communication? I was always lead to believe that under normal circumstances they were good for 3-7km range irrespective of terrain.
Would never rely on any form of radio for emergency communications in this day and age...EPIRB and Sat phones for extreme remote areas do the job far better. Anybody that fits a UHF "just in case I get into trouble" is kidding themselves.
I relate it to the Fire Brigade responding to cats in trees....How many cat skeletons do you see up suburban trees? Likewise how many 4x4's do you see within cooee of a major town with a skeleton behind the wheel?
equipt
Member
Thats what I was thinking, if you use it within a few kms of anyone trying to watch tv or listen to the radio is going to get a nasty surprise when you start transmitting. Also I would not want to be standing too close to the antenna when you do transmit as it may cause some health issues as 50w of electromagnetic radiation at about head height would no be real flash in my opinion.
Aido
Member
95 kg of steel bullbar followed by 2 ton of dualcab travelling at 60kmh would be more of a concern than a little bit of radiation though surely?
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Aido
Member
So back to the original question.
Why not purchase a cheaper yet more powerful unit from OS??
Why not purchase a cheaper yet more powerful unit from OS??
K
Krankin
Guest
look here for ant choice/selection help
Untitled Document
my allrounder 'dummyproof' pick is
Untitled Document
K
Krankin
Guest
again as i said at the start, you need a licence to broadcast with that type of radio/band/power output.
Aussie Frontier
Member
When we used to play with AM SSB rigs and 20watt amps with 9 foot SS whips we could attach a small fluoro tube to the whip and it would light up no worries when we transmitted.However the tape we used to hold the tube there would burn through in a matter of minutes
Higher power can do all sorts of nasty crap inside your truck as well. If it just so happens you have something the right length for the radio wave then that can heat up from the radio waves your transmitting.
There are a lot of reasons they limit us to 5watts
Higher power can do all sorts of nasty crap inside your truck as well. If it just so happens you have something the right length for the radio wave then that can heat up from the radio waves your transmitting.
There are a lot of reasons they limit us to 5watts
K
Krankin
Guest
I would say yes, simply for the reason that just about no one uses the
27Mhz am band radios anymore,
meaning all to your own clear channels.
.
K
Krankin
Guest
Aido
Member
Yes but I dont need a license to buy one
K
Krankin
Guest
no you dont, but to get the channel you want to use on said radio unit, you are meant to purchase the program s/ware from the manufacturer under licence.
but as you know there are ways around that, just as there are ways for the authorities to find and fine offenders, probably not so much on the UHF band but they are fairly strict with the VHF band.
I would think though if you only use them in the bush you should be ok.
BUT, if you happen to program a channel that is allready licenced to another, be prepared to suffer the consequences.
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