This transmitter sends an FM signal in the 88-to 108-MHz range, with a tone of 19 kHz. This can be used to activate the FM MPX pilot carrier indicator, which can be interfaced to external devices. L4 is for use with a 15 CM wire antenna. LI is 9 turns of #26 enamelled wire on a 54-W 10-kQ resistor (carbon type), L2 is 2 turns wound over LI.
L3 is 7 turns of #26 enamelled wire on a 10-ka /4-W resistor.