Model M Manual : Appendix

 

 

Microphone Cable Test

The microphone cable can be tested using a special TEST circuit and TEST connector on the panel of the instrument. First, the Amplifier and Filter Check should be performed to insure that the electronics, chart drive and printhead are performing properly.  Then, attach the microphone cable to the TEST connector and also to the INPUT connector. Turn the POWER switch ON. Verify that the SYSTEM TEST is as shown on the Amplifier and Filters Check in the Appendix. Wait for the chart drive to stop. Set the filter switch to UPPER COLLARS. Then, press the TEST button below the TEST connector. Next, set the filter switch to LOWER COLLARS. Then, press the TEST button again. The following records should be obtained depending upon the position of the filter selector switch. The chart drive is turned ON automatically; therefore, the operator should not turn ON the chart drive switch during this test. The positions of the gain control knobs do not affect this test. Always keep the connectors clean and the cable in good condition. The microphone cable and connectors can be a source of noise and cause faulty operation of the instrument.

	UPPER COLLAR FILTER TEST
	LOWER COLLAR FILTER TEST