and the gain control. telemetry. The lock-on control is only used for telephone The horizontal and vertical position and intensity controls for the oscilloscope are located on the scope mounting plate. All of these controls are on the front pane) (Fig. 17) Procedure l. Connect cables from the 110 volt 60 cps line, recorder and radio. 2. Turn line switch on and press the release button. Ze After five minutes warm-up, bring the recorder to zero by adjusting the zero set control (R-67). ‘The zero test button is pressed to check the zero of the recorder when telemetering rather than the release ‘switch, since it does not affect the counting and switching circuits. Therefore, the recorder will rise to the proper reading immediately after th release of the button. Commence telemetering by pressing the read button and adjusting the level (gain) control (R-3) until the height of the pulses as observed on the oscilloscope is approximately 2/3 the height of the scope face. The switching relays will be heard if the circuit is operating properly. Note: When the telemeter radio channel is used for voice communication, the release button should be pressed, otherwise the central station will be actuated by the voice signal resulting in erratic fluctuations of the recorder. - 45 -