VHF or UHF

[KayeC]

Hey everyone,

I am looking to buy a CB radio and have read there are many types, but UHF and VHF don't talk to each other. Which is better for 4WDing, Convoy and monitoring road issues. Also are there any unwritten rules on how to and not to use a radio? I know Channel 5 and 35 on UHF are emergency use only. Are there any rules of etiquette for talking to strangers if you hear other people on your channel?

Thanks

 

[mikehzz]

The vast majority of 4wders use UHF for their transport comms. VHF is used on some mine sites and in marine radios. HF is used by some overlanders but is generally harder to use and getting replaced by sat phones.

 

[mac_man_luke]

UHF is what you want, VHF is all licenced (maybe some exceptions these days in the marine band but not meant to use on land)

 

[2luxes]

Which is better for 4WDing, Convoy and monitoring road issues.

A lot depends on where you are going. We have a UHF, a HF and a location beacon. The UHF is mainly used in convoys in mountains but it is common to loose contact with the lead car if you are down the back, particularly when driving on winding tracks in deep gorges.

Our HF is for remote desert trips that are almost always solo. We are members of the VKS 737 network.

Sat phones are becoming popular but they don't always work. Mountains seem to be the worst places for them. A few years ago there was and maybe still is a web site for a NSW Blue Mountains search and rescue group that contained information on the different types or radios. They carry a sat phone and a portable HF when out on rescue missions. The HF is because of the problems with their sat phone when down in valleys. They said the satellite that the phones go through is not in the best possible position for Australia.

The big advantage with the HF if you are in trouble is anybody on your channel can hear you within a couple of thousand ks radius. Help may only be a few ks away but they are not going to hear you on a sat phone. They only go to the number you are calling.

 

[KayeC]

A lot depends on where you are going. We have a UHF, a HF and a location beacon. The UHF is mainly used in convoys in mountains but it is common to loose contact with the lead car if you are down the back, particularly when driving on winding tracks in deep gorges.

Our HF is for remote desert trips that are almost always solo. We are members of the VKS 737 network.

Sat phones are becoming popular but they don't always work. Mountains seem to be the worst places for them. A few years ago there was and maybe still is a web site for a NSW Blue Mountains search and rescue group that contained information on the different types or radios. They carry a sat phone and a portable HF when out on rescue missions. The HF is because of the problems with their sat phone when down in valleys. They said the satellite that the phones go through is not in the best possible position for Australia.

The big advantage with the HF if you are in trouble is anybody on your channel can hear you within a couple of thousand ks radius. Help may only be a few ks away but they are not going to hear you on a sat phone. They only go to the number you are calling.

Thank you, so HF is different again. I'll see if I can find that document by NSW BM search and rescue

 

[mac_man_luke]

Sat phones are becoming popular but they don't always work. Mountains seem to be the worst places for them. A few years ago there was and maybe still is a web site for a NSW Blue Mountains search and rescue group that contained information on the different types or radios. They carry a sat phone and a portable HF when out on rescue missions. The HF is because of the problems with their sat phone when down in valleys. They said the satellite that the phones go through is not in the best possible position for Australia.

That would have to be either inmarsat or thuraya which have 1 fixed satellite to the north (each).
Iridium should work everywhere you can see the sky as they have a constellation of many moving satellites, so at worst you might have to wait a few seconds for one to come past (unlikely)

 

[Chatty]

That would have to be either inmarsat or thuraya which have 1 fixed satellite to the north (each).
Iridium should work everywhere you can see the sky as they have a constellation of many moving satellites, so at worst you might have to wait a few seconds for one to come past (unlikely)

Iridium has 66 satellites, each capable of handling 1,100 concurrent phone calls, although apparently two satellites died in 2016 and were awaiting replacement, so there may only be 64 operational.
They are currently launching their new generation satellites capable of providing higher data speeds - no idea on what data will cost though

 

[mac_man_luke]

The new constellation is almost complete, 1 more launch of satellites in the next month or so. Not many of the originals left running (also no more iridium flares!)

 

[Synchro]

At this stage dont worry about Satphones and HF - your specific question related to UHF and VHF. For general 4wding just get UHF as that is what 4wds talk to each other with in close proximity - it a short range communication means.

VHF is mainly used in aircraft, the marine environment (boats) and some other areas. Is not normally used in 4wds unless near the coast and you needed to talk to a boat or elsewhere where you needed to talk to an aircraft - so dont worry about VHF for everyday 4wd use.

Later when you have got the UHF aspect sorted and then come back to the forum to ask about longer range communication such as HF, satphones etc - mainly used in remote travel but helpful in any offroad use - also look at getting a Personal Locator Beacon (PLB) for under $300 for the final failsafe if you have a life threatening event while out and about an cannot contact emergency authorities - is the final failsafe. I carry one in my car all the time. Google Personal Locator Beacon (PLB) to find out about it.

 

[Hoyks]

VHF gave better transmission in hilly areas and in the right atmospheric conditions the signal can skip a good distance. The signal did suffer a bit from distortion though and were very sensitive to the tuned length of the antenna. UHF were around, but they were also expensive so not many ran them.

Then the cheap 40ch UHF came along, around the same $$ as VHF, easier to install and the off the shelf antennae were also more user friendly. The transmissions were clearer, but very line of sight and so didn't perform as well in the hills and were also affected by heavy forest. But if you were on a peak you can punch a clear signal a fair distance.

What to get?
UHF as hardly anyone has VHF anymore and if you want to talk to people on the road, you need compatible equipment.
I know of a few guys that still run VHF as the UHF bands have more than their fair share of obnoxious clowns, but now they have it just about to them selves and a UHF for backup. VHF did too, back in the day, and its one of the reasons a lot jumped across to the new system. But now the clowns have moved across the spectrum too.

There are rules and etiquette, but aren't really enforced. My only suggestion is don't be a dick, and I think there is something in that for all of us.

 

[Ziggy]

Hey everyone,

I am looking to buy a CB radio and have read there are many types, but UHF and VHF don't talk to each other. Which is better for 4WDing, Convoy and monitoring road issues. Also are there any unwritten rules on how to and not to use a radio? I know Channel 5 and 35 on UHF are emergency use only. Are there any rules of etiquette for talking to strangers if you hear other people on your channel?

Thanks

Yes. If breaking in announce a call name and ask permission.
Use the channels for their listed purposes.
If you've raised someone on 10 or 11 to chat move to a conversation channel.
Reception can be unreliable - it's important to repeat back critcal stuff.

 

[2luxes]

Iridium should work everywhere you can see the sky

That was the problem that rescue unit was talking about. You can't always see the sky. They mentioned being under
large dense tree coverage or behind mountains.

 

[silkwood]

UHF is what you want, VHF is all licenced (maybe some exceptions these days in the marine band but not meant to use on land)

As far as I'm aware, all VHF Marine requires a licence (to operate, not to own- as if that makes any sense).

 

[2luxes]

Thank you, so HF is different again. I'll see if I can find that document by NSW BM search and rescue

There is some information about them on this site. http://www.beadelltours.com.au/hf_information.html This is a very serious desert touring company that is owned by the daughter of Len Beadell and her husband. https://www.google.com.au/search?q=...7j69i65j0l4.4408j0j7&sourceid=chrome&ie=UTF-8. Some of their trips include up to seven hundred ks cross country without any roads or tracks to follow. It is an interesting and informative site to look through, particularly the tyre section.

My HF was a rebuilt second hand unit from this company. They should be able to answer all your questions. http://hfradio.com.au/

 

[Ziggy]

That was the problem that rescue unit was talking about. You can't always see the sky. They mentioned being under
large dense tree coverage or behind mountains.

We have four satellite comms providers in Oz and where the satellites are in the sky is something to research because they're not the same.
Iridium has improved in the last couple of years but if you're in a deep hole up north call handover to the next moving sat can be an issue (the satellites are further apart at the equator).
In the south of the country a blocking spur or ridge to the north can be an issue for Globalstar and Inmarsat. (I get regular Spot failures in the Vic high country for this reason as it uses the Globalstar unit; I've yet to have an Inmarsat failure but that doesn't mean it's impossible). Thuraya coverage in the north isn't optimal.

 

[boobook]

There are only two options for land based mobile without licence. 477Mhz UHF, and 27Mhz HF. You can not use VHF at all.
Beyond that you can get an Amateur Radio Licence ( all bands) or a HF mobile radio licence for high Power HF ( thousands of KM range).

99% of people only use UHF CB which has a range of up to about 15km.

If you want longer distance comms then the Land Mobile or Ham options are generally best. 27MMhz SSB is great for touring and up to about 45km range IF you have two people who know how to use it on the trip.