Radio specifications A to D.

Antenna impedance
The impedance that the antenna you connect to the radio should be. For transmitters and transceivers, this is usually 50 Ohms. For receivers, such as broadcast radio and TV equipment, the usual is 75 Ohms.

Audio power
The maximum amount of power into the speaker, the manufacturer may also state the required speaker impedance.
Any speaker connected must have the same impedance, and must be able to take the power level without being damaged.

Adjacent channel rejection
How well the receiver can reject a signal on the channel above or below the one you are using.
For communications equipment, a reasonably good figure is 60dB. A figure of 50dB is common, but can lead to trouble blocking out other nearby signals which you are not tuned to.

Channels
Usually states how many channels are available on the radio. This may include details of the frequency range covered and how the frequencies are generated.
PLL Synthesized means that the radio creates the frequencies from just one reference crystal, rather than separate crystals being used for each channel.

Conversion system
This is the type of receiver used, with Superhet being the standard type used now. Some old communications equipment used single conversion Superhet, but dual conversion is now the usual standard.

Current drain
The amount of electrical current used by the radio. This information is useful when deciding what power supply to get for a mobile radio or what size fuse to fit.

Deviation
This applies to FM transmitters, and states how much your transmit frequency is shifted by your outgoing sound. The maximum level for any specific service is set by law.
With PM transmitters, this may refer to the level of phase shift, in degrees or Radians. As PM also causes frequency shift, deviation may be stated as for FM and stated as Frequency Deviation in KHz.

Dynamic range
A measure of how well the receiver handles signals of different strengths.
This could be quoted as a minimum and maximum signal, in which case a wider range is better. It could also be quoted as a single dB figure, in which case higher is better.

E - L     M - Z

CB Radio     Electronics     Magazine     Privacy     Contact     Accessibility     Site map
Copyright © 2001 - 2008, all rights reserved.