TM 1-1510-218-10 3–87 the   TEST/MON   NO   GO   indicator   may   illuminate.   Disregard this signal. (2)   Test Procedure. NOTE Make  no  checks  with  the  master  switch  in EMER,  or  with  M-3/A  codes  7600  or  7700, without  first  obtaining  authorization  from the interrogating station(s). 1.   Allow set 2 minutes to warm up. 2.   Select    codes    assigned    for    use    in modes   1   and   3/A   by   pressing   and releasing   the   push   button   for   each switch until the desired number appears in the proper window. 3.   Lamp   Indicators.      Operate   press-to- test feature. 4.   M-1 Switch  – Hold in  TEST.  Observe that no indicator lights illuminate. 5.   M-1 Switch – Return to ON. 6.   Repeat  steps  4  and  5  for  the  M-2,  M- 3/A, and M-C mode switches. 7.   MASTER Control – NORM. 8.   MODE  4  Code  Control    –  A.    Set  a code in the external computer. 9.   MODE 4 AUDIO OUT Switch – OUT. (3)   Modes   1,   2,   3/A,   and/or   4   Operating Procedure. NOTE If   the   external   security   computer   is   not installed, a NO GO light will illuminate any time  the   MODE  4  switch  is  moved  out  of the OFF position. 1.   MASTER Control – NORM. 2.   M-1,   M-2,   M-3/A,   and/or    MODE   4  ON/OUT switches  – ON.  Actuate only those  switches  corresponding  to  the required codes. The remaining switches   should   be   left   in   the   OUT position. 3.   MODE   1   Code   Selectors   –   Set,   if applicable. 4.   MODE  3/A  Code  Selectors   –  Set,  if applicable. 5.   MODE    4    Code    Control    –    Set,    if required. 6.   MODE  4  REPLY Indicator   –  Monitor to  determine  when  transponder  set  is replying to an SIF interrogation. 7.   MODE 4 AUDIO OUT Switch – Set as required to monitor Mode 4 interrogations and replies. 8.   MODE   4    Audio    and/or    Indicator   – Listen   and/or    observe    for    Mode    4 interrogations and replies. 9.   IDENT/MIC/OUT   Switch   –   Press   to IDENT momentarily. 10.   MODE  4  TEST  /  ON  /  OUT Switch  – TEST. 11.   Observe that the   TEST  GO indicator light illuminates. 12.   MODE  4  TEST  /  ON  /  OUT Switch.   ON. 13.   ANT Switch – BOT. 14.   Repeat  steps  4,  5,  and  6.    Observe that the TEST GO indicator illuminates. 15.   TOP / DIV / BOT / ANT Switch – TOP. 16.   Repeat  steps  4,  5,  and  6.    Observe that the TEST GO indicator illuminates. 17.   TOP / DIV / BOT / ANT Switch – DIV. 18.   Repeat  steps  4,  5,  and  6.    Observe that the TEST GO indicator illuminates. 19.   When possible, obtain the cooperation of  an  interrogating  station  to  exercise the TEST mode. a.     RAD TEST / OUT Switch – TEST. b.   Obtain verification from interrogating   station   that   a   TEST MODE reply was received.