FM Terminal Transmitter and Receiver For the TH Radio System

The relation of the FM terminals to the over-all TH system is dpscribed briefly in a previous paper. 1 There are two basic types of terminals: an FM transmitting terminal, which converts the baseband signal into a frequency modulated signal centered at 74.1 mc; and an FM receiving terminal, which recovers the baseband signal from the FM signal. The types of baseband signals to be transmitted 1 are shown in Fig. 1. In each terminal appropriate amplification is provided at both the intermediate and baseband frequencies to permit interconnection with other parts of the TH system. FM terminals are required at the ends of a TH route and at intermediate points where the baseband signal, or some portion of it, must be added or dropped. The design is based on a maximum of Hi terminal pairs in tandem in 4000 miles. 1587 1018 T H E BELL SYSTEM TECHNICAL J O U R N A L , S G 112 CHANNELS) || M A S T E R G R O U P 2 || N O V E M B E R 19(31 * (60 P| | MASTERGROUP 1 MASTERGROUP 3 A L L T E L E P H O N E (i860 C H A N N E L S ) TELEVISION SIGNAL 1 NTSC TELEVISION