TM 5-4210-220-34 2-9. SIREN AND PA SYSTEM - Continued Abbreviations  are  used  to  describe  the  SELECTOR  position.    These  abbreviations  and  their  meanings  are  as follows: R = RADIO P= PA M = MANUAL W = WAIL Y = YELP H = HI-LO When a waveform is present at a given point, the waveform is listed by a capital letter, its cycle rate and its peak-to-peak voltage.  For example, the waveform at IC101-3 is listed as A/45-55, 1.  Therefore,  when an oscilloscope is connected to IC101-3, waveform A having a cycle rate of 45-55 cycles per minute (or Hz, if specified) and a nominal amplitude of 1 volt peak-to-peak (Var = varying) should be observed.  All waveforms are illustrated subsequent to the tables. IC101 SELECTOR Voltage or Pin Position Waveform 1 All 10.5 Vdc 2 H 10.5 Vdc 3, 4 H A/45-55, 1 5 H 10 Vdc 6 H 10 Vdc 8 H OV 11 Y OV 12 Y 10.5 Vdc 13 H 10.5 Vdc 14 All 0.5 Vdc 1C102 SELECTOR Voltage or Pin Position Waveform 2, 6 W B/10, 3 2, 6 Y B/160-190, 3 2, 6 H B/45-55, 3 3 w A/109.8 3 Y A/160-190, 9.8 3 H A/45-55, 9.8 4 All 10.5 Vdc 5 All 7 Vdc 7 W C/10, 7 7 Y C/160-190, 7 7 H C/45-55, 7 8 All 10.5 Vdc 2 M 1.9 Vdc 6 M 1.9 Vdc 7 M OV 2-28