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3-7 CHANGING THE FREQUENCY STEP
The specification for channel occupancy, step (separation) and mode are decided by and allocated by the
Departments of Governments following international discussions.
The allocation of frequency bands are not the same all over the world and channel separation (step)
varies from band to band. As an example, the channel separation (step) for the MW (medium wave) band
in the U.S.A. is 10 kHz, and is 9 kHz in Europe and Japan.
If you wish to change the default tuning frequency step, press the [F] key and then the [2] key. The LCD will
display the current frequency step in reverse contrast. Rotate the dial knob to select the desired step.
You have the choice between 10Hz, 50Hz, 100Hz, 500Hz, 1kHz, 2kHz, 5kHz, 6.25kHz, 7.5kHz, 8.33kHz,
9kHz, 10kHz, 12.5kHz, 15kHz, 20kHz, 25kHz, 30kHz, 50kHz, 100kHz, 500kHz.
To validate the displayed tuning step size, press the [ENT] key.
3-8 IF BANDWIDTH
The IF bandwidth determines how SELECTIVE the receiver will be when monitoring signals off air.
However, it is not simply a case of using the narrowest filter at all times; particular modes require differing
amounts of bandwidth in order to operate. Otherwise the receive system will not produce intelligible sound.
Correct receive mode and IF bandwidth must always be selected for optimum reception. If the bandwidth
selection is too narrow, distortion or signal break-up may occur. If the bandwidth selection is too wide,
adjacent interference may be encountered. For this reason, a selection of IF filter bandwidths are
provided as standard.
Typical examples of receive mode and IF bandwidth are:
200 kHz – VHF FM broadcast
30 kHz, 100 kHz – Wireless microphone, etc. (30 kHz for satellite FAX, too)
15 kHz – PMR, amateur band, etc. FM 6 kHz may also be used
6 kHz – VHF/UHF airband, short wave broadcast, medium & long wave, PMR, etc.
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