TM 1-1510-223-10 3-16            An identifier (1 through 6 alphanumeric characters, beginning  with  an  alpha  but  excluding  E,  C,  C  plus  1 through 6, and P). Identifiers are valid only if they exist in the frequency list. If the VHF-FM is in the frequency hopping mode and valid data is scratchpadded, depressing L1 will cause the transceiver to be returned and the display at L1 to be up- dated to reflect the scratchpadded data. Valid data is: A HOPSET channel (0 through 6 or an M). A HOPSET number (3 digit number). An identifier (1 through 6 alphanumeric characters, beginning  with  an  alpha  but  excluding  E,  C,  C  plus  1 through 6). HOPSET and identifier entries are valid only if they exist in the hopset list. NOTE Hopset channel 0 is processed and displayed as an M channel. 1      Displayed data at L1.  The first line of text at L1 is 2-FM followed by an ICS select arrow if the radio has been selected by the transmitter-intercom se- lector switch (audio control panel, fig. 3-1). The text CIPH and a fill number is displayed to the right of the ICS select arrow if the cipher mode has been selected. The second line of text at L1 can read: Channel number/frequency followed by an optional identifier. E (for emergency)/1 followed by 40.5, followed by an optional identifier. Net channel number/followed by a FH followed by the net number in the frequency hopping mode. M/ followed by a frequency if the radio is tuned to a fre- quency list or if the cipher fill number/status is changed after the radio is tuned. The third line of text (L1) may contain one of the fol- lowing messages in the following priority: FAIL - The radio has failed one of several test. EMER - The emergency tune function has been se- lected using the KU EMER switch. TUNING - The ARC-201 is tuning and L1 is inopera- tive. NO TSEC - The FH or FH/M mode is selected and a TSEC  variable  has  not  been  stored  into  permanent memory. (3)    2-FM SETUP page.  The 2-FM SETUP page allows the operator to set up the VHF-FM transceiver. On power-up, the transceiver is put into the self-test mode for  approximately  30  seconds.  During  this  period,  the legend  TUNING  is  displayed  adjacent  to  L1  on  the COMM control page and at the top center of this page and the transceiver will not respond to operator inputs. (a)   SC (single channel) mode.  The data at the top center of the page is: Top line - 2-FM SETUP Second  line  -  Currently  tuned  preset  channel,  fre- quency, and plain/cipher indication plus identifier Third line - FAIL, EMER, or TUNING if appropriate 1    L1.  Successive depressions of L1 will cause the mode to change from SC to FH to FH/M, with the active mode boxed. 2    L5.  In SC mode, this function is a nor- mal clock function. If the scratchpad is blank, depressing R5 will change the display of time stored in the transceiver. If time is not available from the transceiver, the display remains blank. If valid data is scratchpadded, the data will be displayed adjacent to L5 and sent to the transceiver. Valid time data is day (0 through 99), hours (0 through 23), and minutes (0 through 59). Data fields not entered are considered zero. 3    R1.  Successive depressions of R1 will change  the  squelch  from  OFF  to  ON,  with  the  active mode boxed. 4    R2.  Successive depressions of R2 will cause the frequency offset for the selected preset chan- nel to change from 0 to +5 to +10  to -10 to -5, with the active offset boxed. The offset selected for a preset chan- nel is stored with that preset channel. NOTE When  the  EMER  switch  on  the  keyboard  unit (KU) is activated, 40.5 MHz is tuned, squelch is set to ON, and the function keys on the 2-FM AM/FM page are disabled.