Monitor circuits The monitoring circuits include all functions of the monitor panel as well as the monitor amplifier. They are common to both transports and all channels, with the exception of channel 5 on a DAIR recorder. If there is no audio indication on channels 1-4 or 6-9 for both transports, a monitoring problem should be considered. This can be proven by stopping both transports, placing SW201 to the channel 10 position, and switching SW204 to DIRECT. If the monitoring circuits are working properly, the IRIG-E signal should be heard on the speaker and the meter will deflect. This provides an external secondary source of audio for troubleshooting. The monitoring circuits accomplish the following functions: 1. Contains fuse protection for 115VAC primary input power (F201). 2. Provides visual and audible monitoring of audio before and after recording. 3. Provides reset in event of transport failure. 4. Monitor panel switches, indicators, and controls. a. Power switch (SW205)-provides 115VAC power. b. Power on lamp (I201)-indicates primary power is applied to RD-379A. c. Reset switches (SW202/SW203)-resets transports after failure. d. Monitor switch (SW201)-selects one of the 10 channels to be monitored. e. Monitor selector switch (SW204)-selects audio to be monitored from an individual transport. 1. Direct-monitors audio directly from channel selected BEFORE it is recorded on tape. 2. REP 1/REP 2-monitors recorded audio from output of reproduce amplifier 1 or 2. f. VU meter (ME 201)-displays audio level of channel selected by monitor switch. g. Gain control (R201)-controls volume level in headset or loudspeaker. h. Loudspeaker (SPK 201)-provides audible monitoring of audio. i. Phone jack (J201)-allows headset monitoring of audio.