When tuning into an antenna with high SWR the SWR meter reading becomes unstable and a small amount of smoke is seen coming from the antenna tuner.
One of the 3 x 4 self tapping screws that is used to secure the AT unit hinge can occasionally damage the insulation on the brown lead wire. When the tuner is then load into a high SWR the high reflected voltage causes the lead to head up, which further damages the insulation. Eventually the insulation breaks down completely and the wire shorts to the screw causing the lead to overheat and smoke to emanate from the area.
Cut a 12 cm long piece of the fiberglass insulating sleeve and install it over the brown lead wire to prevent shorting.
Qty Description Kenwood Part No. Circuit description
12 cm Fiberglass insulating sleeve 212-3502-05 W101
(Note: The insulating sleeve must be ordered in increments of 1 meter or greater).
Time required for this modification is 30 minutes or less.