Uhf's did you know

[Bloodyaussie]

I was reading up on the old and new formats in uhf and it seems that those with older 40 channel come across very loud to those with the newer 80 channel and those with 80's come across very faint to those with 40 channel users???

Now there will be the experts who will pop out of the wood work now but on many trips of late including the last big one at Woods point the discussion as to how we sounded to each other was never met with any explanation.

"I could hardly here you" and " I had no problems hearing you but could not hear fred at all" was the norm on these trips.

They explain that this problem should be solved with time as more people upgrade to the 80 channel.

Gee never any mention in bloody 4wd action on there "Everything you need to know about UHF's"

Anyway food for thought when thinking about your next purchase.

[Maxhead]

Sorry BA,...what was that. Couldn't hear you!!!!

[Winnie]

I've got a 40 channel and BA at Woods Point I could hardly hear you especially. Everybody else wasn't too bad.

[Bloodyaussie]

I've got a 40 channel and BA at Woods Point I could hardly hear you especially. Everybody else wasn't too bad.

I did not count on that trip as I had other issues..... shut up both of you!!!

Just installed all new set up and my god the chatter..... can hear for miles around.

It has not been right since I had the car, in my Rodeo I could hear and talk for miles but since owning the GQ nothing has been right.

Mostly aerial issues I think.

[Lonicus]

I did not count on that trip as I had other issues..... shut up both of you!!!



There's your problem right there. You keep telling everyone to shut up and then wonder why you can't hear anyone :)

[Bloodyaussie]

There's your problem right there. You keep telling everyone to shut up and then wonder why you can't hear anyone :)

Ha ha ha ha!!!!!!

I am just so use to Kris/Chris giving me shit, it's an automatic defense mechanism when dealing with them two!!!

[Maxhead]

Ha ha ha ha!!!!!!

I am just so use to Kris/Chris giving me shit, it's an automatic defense mechanism when dealing with them two!!!

Still can't hear anything....did you say something?????:)






..........on the move

[lorrieandjas]

Hey BA,

The newer models have narrowband or wideband filter settings - so you can change to wideband if you are communicating more with people on 40 channel sets. They also come with an auto volume feature which (since its a digital signal anyway) automatically adjusts the volume for lower volume transmissions that are received. There's more info on the GME website.

Jas

[stevogq]

Hey BA,

The newer models have narrowband or wideband filter settings - so you can change to wideband if you are communicating more with people on 40 channel sets. They also come with an auto volume feature which (since its a digital signal anyway) automatically adjusts the volume for lower volume transmissions that are received. There's more info on the GME website.

Jas

I have a uniden bcd996t does that have the same settings also for the bands?
Still trying to figure it out
cheers stevo.

[threedogs]

99% of UHF problems will be earthing problems on antenna, Check or run earth to base of antenna to earth on battery,
Should be able to bust this as fact or fiction easy, Who went and how many channels was Their UHF

I have whats called SELECTIVE HEARING if you talk BS I switch off

[lorrieandjas]

Hey guys - from the GME TX3540 manual:

IMPORTANT INFORMATION CONCERNING UHF CB RADIO

The use of the citizen Band radio service is licensed in Australia by the ACMA radio communications (Citizens Band radio stations) class licence and in New Zealand by The Ministry of Economic Development New Zealand (mED). A General user radio licence for citizens Band radio and operation is subject to conditions contained in those licences. The class licence for users and equipment operating in the cB/Prs 477 mHz band has been amended. This radio meets the new 80 channel standard.

In simple terms the same amount of spectrum is available; however, radio transceivers can now operate in a narrower bandwidth and hence use less spectrum. These radios are generally referred to as narrowband or 12.5 kHz radios. By using 12.5 kHz channel spacing instead of 25 kHz, the 40 channels originally allocated can now be expanded to 80 channels thereby doubling the channel capacity and relieving congestion in the UHF CB/PRS band.

Original 40 channel wideband radios will continue to operate on the original 40 channels, however they will not be able to converse on the newer channels 41 – 80. The newer narrowband radios will be able to converse with all older 40 channel wideband radios on all channels 1 to 40 as well as the newer channels allocated from 41 to 80.

The mixing of narrowband and wideband radios in the same spectrum can cause some possible operating issues of interference and varying levels of received volume.

POSSIBLE ISSUES

When a new narrowband radio receives a transmission from an older wideband radio the speech may sound loud and distorted – simply adjust your radio volume for best performance. When an older wideband radio receives a signal from a new narrowband radio, the speech may sound quiet – simply adjust your radio volume for best performance.

Depending on how close your receiving radio is to another transmitting radio, there can be interference from the transmitting radio if it is using a channel adjacent to the channel you are listening to. Simply try going up or down a few channels from the currently selected channel.the above situations are not a fault of the radio but a symptom of operating wideband and narrowband radios in the same bandwidth. this possible interference will decrease over time as the population of wideband radios ages and decreases.

Further information and updates are available from the Australian communications and media Authority (ACMA) at www.acma.gov.au and the ministry of Economic Development (MED), radio spectrum management at: www.rsm.govt.nz

In addition they have the following feature:

BANDWIDTH FILTER SETTINGS
To accommodate the blending of the newer narrowband UHF CB 80 channel plan with the original 40 channel wideband system, your radio is fitted with two user-selectable receiver
bandwidth filters. While either of these will provide superb receive audio, selecting the wide filter will further increase the tolerance of the receiver to 40 channel wideband radios that might otherwise sound over-modulated or slightly off frequency on channels 1 – 40. Selecting the narrow receive filter will increase the selectivity of the radio to strong interfering signals from adjacent channels.

Jas

[TPC]

Hey BA,

The newer models have narrowband or wideband filter settings - so you can change to wideband if you are communicating more with people on 40 channel sets. They also come with an auto volume feature which (since its a digital signal anyway) automatically adjusts the volume for lower volume transmissions that are received. There's more info on the GME website.

Jas

The wide band setting on the new radios will only help with recieving on the new radios, they will still transmit on narrow band and still be quieter when recieved on a 40 ch radio.
The main reason for the wide band recieve switch on the new radios is to get rid of adjecent channel interference from wide band radios.

[Cuppa]

At some stage I plan to fit a CB into the Patrol. I had thought that an older 40 band radio woud be adequate & cheaper, but this seems to be a reason for going with the newer type if I've understood the discussion properly? I expect this is the explanation for why, on my wideband handheld, I could hear TD clear as a bell when we were up at the Murray, but struggled to make out what some others were saying.
So the powers that be have 'wrecked' a perfectly good system, by implementing a new one? Has anyone actually found the 40 extra channels useful?

Cuppa

[Bob]

At some stage I plan to fit a CB into the Patrol. I had thought that an older 40 band radio woud be adequate & cheaper, but this seems to be a reason for going with the newer type if I've understood the discussion properly? I expect this is the explanation for why, on my wideband handheld, I could hear TD clear as a bell when we were up at the Murray, but struggled to make out what some others were saying.
So the powers that be have 'wrecked' a perfectly good system, by implementing a new one? Has anyone actually found the 40 extra channels useful?

Cuppa

You were having trouble hearing me Cuppa and I have a 40 Band but my Arial is placed on the bottom part of my Bull Bar with a short Arial which is not ideal however works OK in Convoy situations and the short Arial is suited for the High Country. I really need to get a better Arial and Place in a better position on the Patrol

[TimE]

A Has anyone actually found the 40 extra channels useful? Cuppa

Yep, great for finding channels without the local yobs exercising their potty mouths and generally being child like.

I have had 40 channel users mention I sound a bit quieter than other 40 channel users, but really they have no problem hearing me. Similarly I have no problems hearing the 40 channel users.

[healy]

I've got a 40 channel and BA at Woods Point I could hardly hear you especially. Everybody else wasn't too bad.

So you have one of those smart uhfs. I call them the BA specials

[threedogs]

I have the Icom 440 can you convert reasonably new model UHF from 40 to 80

Best spot for your aerial/antenna is the centre of your roof, bullbar mounted
with give stronger signal behind and less in front..Those short 4" jobs are the go
if you're prepared to drill hole in your roof, Try for 6Db antenna long for Outback
flat country and short for High country trips ,PICs
from left to right base loaded great antenna use this in camper for 80 channel UHF
centre one is for indash TV ,thick one I use for HWY plus have one have that size for high contry trips

[TPC]

I have the Icom 440 can you convert reasonably new model UHF from 40 to 80

I have a 440N, I will check if the 440 can be changed.

[threedogs]

I have a friend who does this kind of thing but really 80 channels. my little handheld has over 200 channels i can programme.
you dont need an 80 channel job IMO spend your money on something else.

[the evil twin]

Probably the best way to loook at it from a 4WD point of view is this...

A 40 channel set isn't really a 40 channel set for our use. 9 thru 21, 24 thru 29 and 39, 40 are allocated for simplex so that means approx 20 channels.
The rest are associated to repeater, data and emergency use (altho 30 is a tad debatable).

If you factor out the road channels (18, 39 and 40) and the allocations to group useage etc (10, 11, 18, and 29) then that leaves just over a dozen channels to choose from for "users" to chatter on simplex. If you are near industrial areas, ports, mines etc etc those 15 channels can get used pretty quickly.
Out in the boonies then not so much as you will only find a few stations/farms/local businesses on them.

IMHO it is a matter of...
Don't have a CB at all and/or in the market for one... buy an 80 channel
Already have a good 40 channel set and just use it occasionally to chat with mates or to monitor the road channels... stick with the 40
Your a fairly heavy user and/or don't want to necessarily share freq's... buy an 80 channel

The issue of the softer/louder recieve volume is related to the deviation specs and performance of the individual sets. Good quality sets you can hardly tell the difference but wide band is more forgiving if the sets are drifting out of spec or are of poor quality

[Bloodyaussie]

See I knew all the smarty pants would come out of the wood work...

I have my GME 3220 here in 40 channel that receives no problem but when sending it breaks up... is it worth repairing so I can sell it or use it as my home unit???

Just gave my other 80 channel micro uniden to my mate, only just over a year old as I wanted a full size unit with all the bells and whistles !!

[the evil twin]

snip...

I have my GME 3220 here in 40 channel that receives no problem but when sending it breaks up... is it worth repairing so I can sell it or use it as my home unit???

Just gave my other 80 channel micro uniden to my mate, only just over a year old as I wanted a full size unit with all the bells and whistles !!


Re the GME...
It will cost you more to repair then you will get if you sell it... unless you pop the case off and can spot a dry joint or dodgy connection and DIY

Re the 80 channels...
You pretty much answered your own question. if you want the bells and whistles then you want an 80 channel set

FWIW...
I pretty much only use fully programmable commercial sets these days. My main set in my truck is dual band VHF Hi band and UHF and will hold 800 channels and Tx power up to 50 Watts (before anyone has a cow it is set at 5 Watts for the CB freq's and 20 watts on the licenced Channels I use for work and play).
You can get these for less than a GME or Icom CB set and then have channel banks such as...
1 to 40 wide band,
1 to 80 narrow band,
a bank of your fav's
emergency stations (for monitoring only naturally) such as SES, Fireys, Rangers etc

[Bloodyaussie]

I want a cow right now but it looks like the steak is out and it is lasagna !

I am happy with the set I got and it was worth the hassle of fitting a dinn unit for once instead of mounting it in some odd spot.

I do want to get the remote mic for it though ....

[the evil twin]

Isnip...
I do want to get the remote mic for it though ....

Roger that :smileyvault-cute-bi

Hey I made a funny...

I don't bother with din size anymore as Remote mic's are heaps easier to work with...
We have to mount the mike anyway so if controls the Transciever then that bit can go anywhere and most of the remote mic options are only a few extra bucks

[Bloodyaussie]

Roger tea kettle BBQ .... It's already done and fitted!!!! And I like it!!!

[GQ TANK]

Has any one considered turning down the transmitt deviation on the 40 channel rigs?

The first 40 chanels on a 80 channel rig use the same freq - but with 12.5 khz channel spacing. The top 40 channels use the channles between .

The other problem that can occur is a radio operating on a 12.5 khz channel may "block" the transmission from a older 40 channel rig running 25Khz

Most common fault I have found when people have complained that they arnt getting out or receiving is poorly terminated connectors, incorrect connectors or cable.

[the evil twin]

Has any one considered turning down the transmitt deviation on the 40 channel rigs?

The first 40 chanels on a 80 channel rig use the same freq - but with 12.5 khz channel spacing. The top 40 channels use the channles between .

The other problem that can occur is a radio operating on a 12.5 khz channel may "block" the transmission from a older 40 channel rig running 25Khz

Most common fault I have found when people have complained that they arnt getting out or receiving is poorly terminated connectors, incorrect connectors or cable.

Technically they should never block each other. The old band width is 25 kHz channel spacing but the allowable deviation is only 5 kHz. The new bands are 12.5 kHz spacing with 2.5 kHz deviation ergo unless something is way out of spec the modulation will be well off the adjacent freq's and you shouldn't get any adjacent channel interference.

Totally agree with your last comment on poor terminations, damaged/corroded feeds, impedance mismatch etc as well