TM   11-5820-890-10-1 LD   (load). (stand by). (zero  FH). MODE switch. Set RT mode. MODE   Switch SC   (single   channel). FH (frequence hopping). (frequency hopping  master). Used   for   loading   SC   frequencies,   FH   data,   and COMSEC  key  data.  Used  to  receive  ERF. Turns  of  primary  power  to  the  RT,  HUB  remains operational.  In              radio  draws  HUB  power  to maintain memory (SC, COMSEC, and FH data) and maintain  sync  time  for  24  hours.  Use  SQ  ON  rath- er   than                        listening   silence. When FCTN is set to this position, all FH data is cleared   after   five   seconds.   Procedure   for   ra- dio  out  of  operation  calls  for  pausing  in  the               position for five seconds before going to the position. This ensures that RT is completely cleared of FH data. NOTE For a complete view of   RT   front   panel, see  page  2-2. Places RT in SC mode. Places RT in FH mode. Places RT in frequency hopping master mode. This position is to be used only by NCS (and alternate NCS) stations. If more than one station uses this po- sition, net communication may be lost.  SINCGARS OPERATORS: DO NOT USE THIS POSITION!  Pull knob to select COMSEC switch. Sets COMSEC mode of RT. COMSEC COMSEC   Switch (plain  text). CT  (cipher  text). TD   (time   delay). RV (receive variable). (zero) NOTE For a complete view of   RT   front   panel, see  page  2-2. Places  RT lain text (not secure) mode. Pull knob to   select   PT d Places RT in secure mode. Places RT in secure mode. Used when necessary to compensate for transmission delays due to distance between  communication  links. Used when receiving remote fill of COMSEC key. Used to clear COMSEC Instantly clears chan- I3 nels  1  thru  5  when  set  to  Z .  Hold    in        position for  5  seconds  to  clear  key  in  channel  6.  Pull  knob to  select 2-3