Author: Trio-Kenwood Communication, inc.
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.
PROCEDURE:
On the Control Unit (X53-1290-XX)
Check transistor Q8. If it is not a 2SC1815Y change it to this type (Serial numbers 408XXXX-509XXXX).
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)
TP-1 6.0v (L18 adjusts)
TP-2 70 MHz
TP-3 45.3 MHz
TP-4 6.35v (L10 adjusts)
Time required for this modification is 1 hour or less.
73
Jeff
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.
PROCEDURE:
On the Control Unit (X53-1290-XX)
Check transistor Q8. If it is not a 2SC1815Y change it to this type (Serial numbers 408XXXX-509XXXX).
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)
TP-1 6.0v (L18 adjusts)
TP-2 70 MHz
TP-3 45.3 MHz
TP-4 6.35v (L10 adjusts)
Time required for this modification is 1 hour or less.
73
Jeff
