Service BulletinAmateur Radio Division

Subject: TS-430S - PLL Unlock at High Temperatures (Revision)Date: September 14, 1985

This service bulletin supercedes bulletin 891, which concerned low input level to IC-16 as the radio warmed up. This bulletin incorporates information contained in bulletin 891 plus additional information.


On the Control Unit (X53-1290-XX)
  1. Check transistor Q8. If it is not a 2SC1815Y change it to this type (Serial numbers 408XXXX-509XXXX).
  2. For serial numbers before 408XXXX change R29 to 820 ohms and C41 to 100 pF.

In addition to the changes listed above check for the following signals: (You must check these at a dial frequency of exactly 14.000.000 MHz)

  1. TP-1 6.0v (L18 adjusts)
  2. TP-2 70 MHz
  3. TP-3 45.3 MHz
  4. TP-4 6.35v (L10 adjusts)
Time required for this modification is 1 hour or less.

©1985 Kenwood U.S.A.