Outer Limits 4x4 Board

Posted: **Mon Apr 28, 2008 2:58 am**

Hey guys, I posted this elsewhere but i thought i'd pop it on here too in case some aren't aware of it.

The ACMA which is the authority on the radio frequency spectrum is looking at changing most of the 400 mhz band to 12.5khz spacing from the current 25khz spacing. The ACMA acknowledges that the UHF CB band is the busiest part of the spectrum in australia and they are thinking about making some major changes to it to try and reduce congestion.

What this means is that there would be the availability to have a channel between each of the current 40 channels increasing the amount of channels to 80. This will definately not have any advantage in the country but in most built up areas every simplex channel is usually full and repeaters are full of idiots. If the channel allocation were to increase and the amount of repeater allocations were to double then there would be twice as many channels and repeaters and this would free up a lot of the garbage and traffic that clogs up the channels, and will clog up the channels in the future as more users get uhf cb's.

The ACMA has drawn up a Consulatation paper to seek feedback and submissions from people who use the CB band to see if we should keep it the same or increase the amount of channels. Link: ACMA - IFC 06/2008

6.1.2 UHF CITIZEN BAND—INCREASE IN AVAILABLE CHANNELS
The UHF Citizen Band (CB) comprises forty 25 kHz channels. Use of UHF CB is supported by a class licence. Anyone may operate UHF CB equipment provided that operation and the equipment used is in keeping with the conditions of the licence. Users do not have to apply for a licence and no fees are payable by CB radio users.

UHF CB equipment is cheap compared to typical land mobile equipment. Eight repeater channels are available, increasing the potential range of use to tens of kilometres. Australians are enthusiastic users of UHF CB for business and personal purposes. The main disadvantage to users is that no protection from interference is offered and therefore channels may be subject to congestion.
In light of the overall considerations in the band outlined in this paper, including the possibility of a reduction in channel bandwidth elsewhere in the band, it may be desirable to extend this potential bandwidth reduction to UHF CB. The existing 25 kHz channel bandwidth would be reduced to 12.5 kHz via an appropriate migration scheme.

For an environment such as UHF CB, where there is a very large quantity of existing equipment in use, a scheme where the old and new equipment have a degree of compatibility is desirable. This may suggest that the interleave method of yielding more channels could be the most appropriate.
If an 80 channel UHF CB band is to be implemented, ACMA anticipates that there would be a period of time during which existing equipment using 25 kHz bandwidth would be permitted to continue operation, and new 80 channel 12.5 kHz equipment would also be permitted to operate. After the phase-out date only the use of 12.5 kHz channel equipment would be authorised. Use of 25 kHz bandwidth UHF CB equipment would not be supported.
It is acknowledged that arrangements would need to be addressed to preserve the utility of the emergency channels throughout any transitional period.

18. ACMA seeks views on increasing the number of UHF CB channels from 40 to 80 by the implementation of 12.5 kHz channelisation, with a corresponding phase-out of 25 kHz channel equipment.

Yes, this means that eventually all current and old UHF CB radios would be non-compliant with new ones. Whether that's 5 or 10 years away who knows but most people who own GME and Icom and other commmercial grade radios will simply be able to get them reprogrammed. Others such as Uniden won't be so easy.

The contact info is at the link if you're like to have your say.

Anyway, i'm all for it. I think it's a top idea as there are sometimes never enough channels and always never enough repeaters for repeater jockeys

cheers

Posted: **Mon Apr 28, 2008 3:49 am**

I wonder with the channels this much closer, would there be much splatter carried over? (I'm no radio techie!) But I remember back when AM was all the rage, we had terrible problems with it, particularly if a side band user was near by. Or one of the new flash truckies with the new (back then!) UHF would splatter the hell out of AM!

Just hope telstra don't get wind of this and start on the bandwagon of over-priced UHF sets as the old network gets made obsolete.... deja-vu!

Posted: **Mon Apr 28, 2008 3:55 am**

Yep, the Bleed-over or splatter would be terrible, as many people know about using 25 Watts, illegally and the poor bugers on the receiving end, probably wont be using sub-tone to block it out!

Also the over-deviating truck drivers will cause splatter too

Posted: **Mon Apr 28, 2008 6:12 am**

12.5 spacing is common in the rest of the radio world, So I can't see a problem.

Posted: **Mon Apr 28, 2008 7:26 am**

Doesn't STSS (i think it is called) already combat this. You know where you can select a channel and then a point within that channel so you can all go to channel 3.6 instead of just channel 3. Therefore in effect already having 400 channels (40x10)

Posted: **Mon Apr 28, 2008 9:16 am**

Compatability between the 25khz equipment and the new 12.5khz equipment may be an issue though.

It may not be a good time at the moment to race out and buy a new UHF.

Posted: **Mon Apr 28, 2008 2:34 pm**

if its 12.5khz then the 40 channels will still be there wont they? and just add "half channels"?
wont really affect me with my radio equipment

i vote yeh do it

Posted: **Mon Apr 28, 2008 4:45 pm**

something like an ic400 wouldnt be effected by this would it? other than perhapse a little programming

Posted: **Mon Apr 28, 2008 4:59 pm**

badger wrote:something like an ic400 wouldnt be effected by this would it? other than perhapse a little programming

reprogram the extra frequencies

Posted: **Mon Apr 28, 2008 5:00 pm**

Cheaper radios will probably suffer from 12.5Khz spacing, mainly from lack of selectivity between channels. Not sure what the maximum deviation spec is under the current regs, probaly 5Khz? That may need to be tightened to 3Khz...

Posted: **Mon Apr 28, 2008 5:50 pm**

Mr Sausage wrote:I wonder with the channels this much closer, would there be much splatter carried over? (I'm no radio techie!) But I remember back when AM was all the rage, we had terrible problems with it, particularly if a side band user was near by. Or one of the new flash truckies with the new (back then!) UHF would splatter the hell out of AM!

Just hope telstra don't get wind of this and start on the bandwagon of over-priced UHF sets as the old network gets made obsolete.... deja-vu!

if youre getting splatter from 477Mhz to 27Mhz you have other problems to worry about

Posted: **Mon Apr 28, 2008 6:26 pm**

I cannot see it phasing out older radios other then your old radio would then be channels

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

this is only an assumption but as the freq rang itself isnt changing then i cannot see them not working entirely just you only get every second channel

Posted: **Mon Apr 28, 2008 7:21 pm**

Micky-Lux wrote:Compatability between the 25khz equipment and the new 12.5khz equipment may be an issue though.

It may not be a good time at the moment to race out and buy a new UHF.

just thought that myself

Posted: **Mon Apr 28, 2008 8:11 pm**

BASSYK wrote:
Mr Sausage wrote:I wonder with the channels this much closer, would there be much splatter carried over? (I'm no radio techie!) But I remember back when AM was all the rage, we had terrible problems with it, particularly if a side band user was near by. Or one of the new flash truckies with the new (back then!) UHF would splatter the hell out of AM!

Just hope telstra don't get wind of this and start on the bandwagon of over-priced UHF sets as the old network gets made obsolete.... deja-vu!
if youre getting splatter from 477Mhz to 27Mhz you have other problems to worry about

I was thinking something similar.

Posted: **Mon Apr 28, 2008 8:37 pm**

LuxyBoy wrote:Doesn't STSS (i think it is called) already combat this. You know where you can select a channel and then a point within that channel so you can all go to channel 3.6 instead of just channel 3. Therefore in effect already having 400 channels (40x10)

CTCSS is just a squelching trick - it silences your radio until it 'hears' it's 'activate' code. The dude on the other end, his radio 'sends' the code before every transmit. Older radios will have Selcall, which was similar except you had to 'silence' your radio, then it would stay silent until someone sent your code, more like dialing a phone. Once it was un-silenced, it was open and you'd hear everything.

Both of these systems are "selective calling" - ie the just tell the radio to stay silent until it's told (with a code) to wake up/speak up - they don't actually add channels.

Posted: **Mon Apr 28, 2008 10:27 pm**

Brainless wrote:I cannot see it phasing out older radios other then your old radio would then be channels

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

this is only an assumption but as the freq rang itself isnt changing then i cannot see them not working entirely just you only get every second channel

this is how i see it...

Posted: **Mon Apr 28, 2008 10:34 pm**

macca81 wrote:
Brainless wrote:I cannot see it phasing out older radios other then your old radio would then be channels

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

this is only an assumption but as the freq rang itself isnt changing then i cannot see them not working entirely just you only get every second channel
this is how i see it...

However... in 5 years time if you are on ch1 in Narrowband 12.5khz and someone comes on with one of those old clunker GME 3200/3400 or uniden uh-015 radios which still uses 25khz and wideband, then your poor 12.5khz narrowband radio might get it's speaker blown to bits

(well not literally)

Moral of this thread, always buy icom - the radio of the future (literally)

Posted: **Mon Apr 28, 2008 11:08 pm**

Jeeps wrote:However... in 5 years time if you are on ch1 in Narrowband 12.5khz and someone comes on with one of those old clunker GME 3200/3400 or uniden uh-015 radios which still uses 25khz and wideband, then your poor 12.5khz narrowband radio might get it's speaker blown to bits (well not literally)

UHF uses FM. It's been a while since I studied this stuff, but I believe FM uses bandwidth differently to AM, so a 25kHz FM signal won't necessarily stomp over a 12.5kHz neighbour like AM signals will.

We have some radio gurus here - anybody got any pics/charts/etc?

Posted: **Tue Apr 29, 2008 2:23 am**

I believe it does but only in close proximity, just tested my base on 476.425 WB (current channel 1) and handheld on 476.4375 WB (possible future channel 2) and managed to get occasional interference from each other. However with both on NB it was fine and with the base changed over to the antenna on the other end of the house it was reduced significantly. There is probably a lot of overload to the base also from me sitting 2 metres from it keying up the handheld in the same room

I'm sure that the distance most cars would have while in convoy would be sufficient to stop the interference however.

cheers

Posted: **Tue May 06, 2008 5:32 pm**

Jeeps wrote:
macca81 wrote:
Brainless wrote:I cannot see it phasing out older radios other then your old radio would then be channels

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

this is only an assumption but as the freq rang itself isnt changing then i cannot see them not working entirely just you only get every second channel
this is how i see it...
However... in 5 years time if you are on ch1 in Narrowband 12.5khz and someone comes on with one of those old clunker GME 3200/3400 or uniden uh-015 radios which still uses 25khz and wideband, then your poor 12.5khz narrowband radio might get it's speaker blown to bits (well not literally)

Moral of this thread, always buy icom - the radio of the future (literally)

Unfortunately it doesn't work that way, be it sometimes it appears like it, for analogue systems the Power Spectral Density is stronger per unit bandwidth for the narrow band option.

I was at the conference where they released the document, also invovled in the development of many of these types of documents and technical studies while I was employed at the regulator. The grandfathering period will be between 3 and 5 years for the older equipment unless the clubs respond to the discussion paper. This is the concern. 12.5 KHz channeling is a world wide standard in CBRS and Land Mobile arenas, including Police and emergency service equipment from around the world.

I started a thread earlier but will remove it as I was not aware of this thread. (Was in Melbourne at the conference...)

They will not listen to individual complaints etc, but a well approached array of club and "Grey Nomad" concerns will help the Transition period extend out to the 5 or 7 year mark.

G

Posted: **Tue May 06, 2008 6:19 pm**

grungle99 wrote:
Jeeps wrote:
macca81 wrote:
Brainless wrote:I cannot see it phasing out older radios other then your old radio would then be channels

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79

this is only an assumption but as the freq rang itself isnt changing then i cannot see them not working entirely just you only get every second channel
this is how i see it...
However... in 5 years time if you are on ch1 in Narrowband 12.5khz and someone comes on with one of those old clunker GME 3200/3400 or uniden uh-015 radios which still uses 25khz and wideband, then your poor 12.5khz narrowband radio might get it's speaker blown to bits (well not literally)

Moral of this thread, always buy icom - the radio of the future (literally)
Unfortunately it doesn't work that way, be it sometimes it appears like it, for analogue systems the Power Spectral Density is stronger per unit bandwidth for the narrow band option.

I was at the conference where they released the document, also invovled in the development of many of these types of documents and technical studies while I was employed at the regulator. The grandfathering period will be between 3 and 5 years for the older equipment unless the clubs respond to the discussion paper. This is the concern. 12.5 KHz channeling is a world wide standard in CBRS and Land Mobile arenas, including Police and emergency service equipment from around the world.

I started a thread earlier but will remove it as I was not aware of this thread. (Was in Melbourne at the conference...)

They will not listen to individual complaints etc, but a well approached array of club and "Grey Nomad" concerns will help the Transition period extend out to the 5 or 7 year mark.

G

yes, but just like AM CB radio sets, which were upgraded with upper and lower sidebands for every channel, the old sets still work, they just cannot access the upper and lower sidebands.

so from my understanding, the old radios will simply only be able to access channels 1 3 5 7 9 11 13 etc.

And if you want to talk to someone with an "old clunker" as someone put it, then you just pick on of those channels.

The newer radio's will effectively be transmitting at double the power? Assuming the transmision power is not reduced in line with the reduced bandwidth.

Posted: **Tue May 06, 2008 9:03 pm**

just buy quality equipment and you dont have to worry

Posted: **Wed May 07, 2008 5:47 pm**

yes i dont think it will be a major issue........

ps my uhf aeriel and speaker for sale for a bargain at $150 think its 2 cheap and scaring people off so next week price goes up

give the consumers what they want

unit is sweet, just i have the boss buying me the faceless gme

Posted: **Wed May 07, 2008 10:29 pm**

so does this mean the cheap cb i bought of ebay (turns out it was from the u.s.)will work in aus

Posted: **Wed May 07, 2008 11:08 pm**

defmec wrote:so does this mean the cheap cb i bought of ebay (turns out it was from the u.s.)will work in aus

is it a FRS radio?

Posted: **Fri Oct 03, 2008 9:56 pm**

Any more news on this? I'm looking at buying a GME TX3440 which has 25MHz channel spacing TX/RX but only RX on 12.5MHz.

Don't want to splash the cash if it's going to be useless in a few years time.....

Not keen on spending an extra couple of hundred to get a comparable Icom if its not necessary.

Posted: **Sun Oct 05, 2008 9:31 am**

Moph wrote:Any more news on this? I'm looking at buying a GME TX3440 which has 25MHz channel spacing TX/RX but only RX on 12.5MHz.

Don't want to splash the cash if it's going to be useless in a few years time.....

Not keen on spending an extra couple of hundred to get a comparable Icom if its not necessary.

Call GME and ask if it will be possible to re program it ?

Outer Limits 4x4 Board

HAVE YOUR SAY. UHF CB to increase to 80 channels

HAVE YOUR SAY. UHF CB to increase to 80 channels