Thread: UHF Advice please...

Not many people use HF 27 Mhz CB anymore
UHF 477 Mhz is the most popular now. New ones should have 80 channels.
Don't know if US uses came Channels as Australia.

Gary

Originally Posted by ThorneGator

I will be in the U.S. In a few weeks and am curious if purchasing a CB, UHF over there is worth while, price. Would they use the same frequency?

The frequencies used for Australia's UHF CB are unique and a US set will not be of any use here.
80 Channels are for the UHF and basically will be using less deviation (12.5KHz instead of 25KHz) so they can fit more channels into the UHF CB Band. You want a programmable set so you can load the old 40 Channels with 25KHz deviation and the new Channels with 12.5KHz deviation. later, when 40 channel sets are all in the scrap heap you can then change the original 40 Channels to 12.5KHz.
In an nutshell, while 12.5 and 25 can work together, transmitting with 12.5 will sound low audio on a 25 set. On the other hand 25 will splatter over the 12.5 channels that are in between the current channels.

Originally Posted by HowardSmall

The frequencies used for Australia's UHF CB are unique and a US set will not be of any use here.
80 Channels are for the UHF and basically will be using less deviation (12.5KHz instead of 25KHz) so they can fit more channels into the UHF CB Band. You want a programmable set so you can load the old 40 Channels with 25KHz deviation and the new Channels with 12.5KHz deviation. later, when 40 channel sets are all in the scrap heap you can then change the original 40 Channels to 12.5KHz.
In an nutshell, while 12.5 and 25 can work together, transmitting with 12.5 will sound low audio on a 25 set. On the other hand 25 will splatter over the 12.5 channels that are in between the current channels.

What you say may be right in theory but having done several trips with mixed radios in the groups (40 and 80 channel sets) I haven't experienced any significant issues.

Cheers
KarlB

Probably because in practice, as well as theory, it shows itself in the audio from a 12.5KHz transmission coming out at a lower level on a 25KHz receiver. However, depending on who programmed the 80 channel sets, the original 40 channels may be set at 25KHz to avoid that problem. Further, if one person uses a 40 channel set and the other uses an 80 channel set to talk to each other it will not be noticed as the user with the 40 channel set will just turn the volume up a bit more...

Also, it is unlikely that you were working on one of the new channels while someone within range was working on an old channel adjacent to the new one. Hence the splatter problem would not show up - it is more likely in the overcrowded cities where no one wants to use UHF CB anyway...

Howard

Originally Posted by KarlB

What you say may be right in theory but having done several trips with mixed radios in the groups (40 and 80 channel sets) I haven't experienced any significant issues.

Cheers
KarlB