During the 1980's, Fortop produced a range of ATV equipment. Two of their early price lists/catalogue listings are here:
TVT437 ATV Transmitter
The TVT437 was a 250mW 70cm AM ATV Transmitter. The full specification, assembly instructions and circuit diagram are here.
TVT435 ATV Transmitter
The TVT435 was a boxed 15W 70cm AM ATV Transmitter. It included a TVT437 and a TVPA435 in a single die-cast box with aerial changeover. The specification is here.
TVL435-20 ATV Power Amplifier
The TVL435-20 was a 15W 70cm AM ATV Power Amplifier. The specification is here.
TVD100 Video Demodulator
The TVD100 was an AM Video demodulator for 70cm Transmitters. The specification is here.