Model:         IC-12AT

 Division:      Amateur

 Note:          This service bulletin is meant for technical per-
                sonnel with experience working on solid state com-
                munications equipment.  Damage caused by im-
                properly installing this modification may cause
                ICOM to charge for subsequent repairs to the
                product.  ICOM does not warrant this modification.


 Bulletin #:    28Oct86-019

 Date:          October 28, 1986

 Subject:       Improve RIT and VXO operation

 Procedure

  1.  Replace C116 (1 mf 50V currently) on the Main board with a
      .22 mf 50 V capacitor.



 Bulletin #:    22987-008

 Affected S/Ns: Less than S/N 4101

 Subject:       Improve the stability of the CTCSS tone in trans-
                mit

 Procedure

  1.  Remove and replace the following components:

      Component      Old       Component      New
      Identifier     Value     Location       Value

      C383           470 pf    PLL Board      Remove this part
      R369           39K       PLL Board      22K
      R370           2.2K      PLL Board      2.7K
      C102           .0027 mf  Main Board     .0018 mf 50 V



 Bulletin #:    22987-009

 Subject:       No memory retention and CPU locks up

 Information:   Lithium battery is dead because D112 is shorting
                to the flex board

 Procedure

  1.  Trim excess lead from D112 and carefully re-solder.