CB UHF & HF Communication

When considering the type of communication system you want it will be necessary to understand the capacity of some of the types of communication devices available.

Terms

MHz - refers to the radio frequency on which the equipment operates.

Simplex – UHF transceivers transmit and receive on the same channel.  To communicate through repeaters, your transceiver must be able to transmit and receive on different channels (known as duplex).

Duplex – allows transmission on a different frequency to that which it receives.

Repeaters – a repeater system consists of a linked transmitter/receiver combination installed in a prominent location.  The repeater is designed to receive signals on a designated channel and re-transmit them on another channel.  Repeaters are normally located on hills, mountains or tall buildings.

SSB –  single sideband comes in three modes AM, USB (upper side band) and LSB (lower side band).  The SSB is better for long distances and/or when signals are weak as power is directed to one sideband and the radiated power is increased.

Selcall – this stands for selective calling to selectively call a friend over the air.  The transceiver is factory programmed with its own unique Selcall Identification Number (Ident).  This number identifies your radio from others in your area.  So you need to make your Ident known to anyone  who may need to call you with Selcall.   When your Ident number is called your transceiver will beep to alert you.

Radphone – or ‘radio telephone’ is where a connection is made with the public telephone network from a base station you call over a suitably equipped HF radio.  A service fee and call costs apply. A selcall is made to the provider’s base station, then key in the telephone number on the radio interface and commence the call when answered.  Conversations are not private.