TM  1-1520-240-10            3-2-13 CONTROLS/ INDICATOR FUNCTION POS. 1-6 In single channel mode, preset frequencies are selected or loaded. In FH or FM-M mode, frequency hopping nets are se- lected. CUE Used by a non-ECCM radio to signal to CUE or ECCM radio. IFM RF Selector OFF (Bypass) - 10 watts LO (Low Power) -2.5 watts NORM (Normal) -10 watts HI (High power) - 40 watts Display The display generally operates in conjunction with the key- board. Other displays may be selected by the FUNCTION and MODE selectors. Keyboard A 15- button array of switches in a 4 x 4 matrix, used to insert data or select data for display. The keyboard is comprised of 10 numerical buttons, three special functions, and two command buttons. Switches 1 - 9 Used to key in frequencies, load time information, or off- sets. CLR Used to zeroize the display or to clear erroneous entries. 0 (H-LD) Used to enter zeroes. Second function (hold) initiates transfer of ECCM parameters. STO/ENT Initiate entry of all data by key- board entry. Its second func- tion is to store a received Hop- set or Lockout Set held in hold- ing. FREQ Display the current operating frequency during single chan- nel (manual or preset) opera- tion. CONTROLS/ INDICATOR FUNCTION SEND/OFST Modify a single channel oper- ating frequency, manually se- lect or preset, to include offsets of + 5 or +10 kHz. It has a sec- ond function on initiating an ERF Transmission if a Hopset or Lockout. Set is in the holding memory and the Mode Switch is in the FH-M position. TIME Used to display or change the time setting maintained within each RT. FILL Used to fill ECCM parameters from an external fill device. Entry of ECCM parameters is initiated by the H-LD button on the keyboard with the FUNC- TION switch in LD or LD-V. Figure  3-2-6.  VHF/FM Radio Set (AN/ARC-201) 3-2-18.  Voice Security Equipment TSEC/KY-58. The voice security equipment is user with the FM band of the No. 1 VHF AM/FM radio to provide secure two-way communication. The equipment is controlled by the re- mote control unit (RCU) Z-AHP mounted on the right side of the console. The POWER switch must be at ON, re- gardless of the mode of operation, whenever the equip- ment  is  installed.  Power  to  operate  the  voice  security system  is  supplied  by  the  No.  2  DC  bus  through  the COMM KY-28 circuit breaker on the No. 2 PDP.