Trunked? Is that the random swapping of frequencies?

Taxi. They used to use Selcall for their pre-digital dispatcher radio ops all the time

Geewiz. Time to toss the Uniden out of the window and upgrade then. But how do I find out whether or not it is trunked or Digital scanner I need to get. All I seem to get on the Cop frequency is that Squelch sound.

Buy a 796D. It does Trunked, Digital and Digital Trunked - Can't go wrong there!

Not random. It is organised.

This is a shotty example of how the Motorolla Trunking works:

For each 'base station' There is a control (data) channel, and a number of voice channels. On your Trunked radio, you enter all of the frequencies, and also enter the TALK GROUP you want to be part of.

The data channel is constantly telling radio's which frequency their talk group is operating on.

The chatter on the data channel is somewhat like; 44208 - Go to 417.0175, 38084 - You're no longer on 415.025

Frequencies only get assigned to talkgroups which are in use. The end result is that you can have more discrete groups operating on less channel space - which means less licencing and less radio gear.

In the case of NSW GRN, they may have up to 30-40 services all operating between about 10 frequencies. If they weren't trunked, they'd need to operate 30-40 repeaters, and pay licencing on 30-40 frequencies. Big $. Especially when you remember that there are around 50 base sites in NSW. 50x40= alot of money in licencing an radio gear!

I have got an Uniden UH-013 fitted in my car & I use it to listen to the cops on the Sunshine Coast, I also use the radio as my UHF radio.

You will find picture of the rig in the link below & in my user gallery...