Modifying the TS-530 Rectifier Unit - Part 1
To accommodate a transverter, the Screen Grid voltage must be made negative - so the PA tubes will not amplify while the radio is in Transmit mode. In the TS-830 series, this is accomplished via a relay on the Rectifier Unit. Said relay is controlled by the rear-panel Screen Grid switch (by bringing one side of its coil to ground) or via an attached transverter (which brings a line on the Xverter connector to ground on power-up). The 530's Rectifier Unit is missing some key components; fortunately, these are easy to add. The PCBs are identical except for the part numbering.
Comparing the '830 Rectifier Unit schematic
830-Rectifier-Unit.jpg
to that of the '530
530-Rectifier-Unit.jpg
it becomes apparent that Kenwood cost-cut the latter while keeping the higher-voltage sections the same. Missing is the relay and its external control circuitry. Kenwood opted to run Screen Grid voltage directly through the 'SG' switch and reworked the area involving the -C, AC100 and SGS terminal. This is simple to reverse.
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