STANDARDS FOR MICROWAVE FM ATV

Mode of emission:F5/F3

Video bandwidth (3 dB):5 MHz

Pre-emphasis:CCIR recommendation 405.1

Colour sub-carrier frequency:4.433618 MHz

Maximum instantaneous modulation index:0.5

Peak deviation (with pre-emphasis):3.5 MHz

Channel bandwidth:12 MHz at -40 dB

18 MHz at -60 dB

Sound sub-carrier frequency:5.5 or 6 MHz

Sound sub-carrier amplitude

(with respect to peak video):-14 dB

Sound sub-carrier modulation index:0.2

Notes

1. A video filter having a -3 dB bandwidth of 5 MHz should be included in the modulating amplifier.

2. A video peak clipper should be included after the video filter.

3. DC clamping of the video signal should be included to prevent the nominal carrier frequency from changing with different television scenes.

4. An RF output filter should be included to prevent out of band energy from whatever source from reaching the aerial system.

5. When it is necessary to reduce the transmitted bandwidth below that shown above the sound carrier should be reduced in level or be removed altogether.¹