SEM25 army radio mechatronics (archive video)

This is a short archive clip of the mechanical adjustment of the filtering in the SEM25 army radio. (The housing is partially removed to see the inside of the radio.) When the desired MHz and kHz selection is made, the resistance of the selecton is known. The servo drive is also equipped with a resitor network. If the mechanical filters are in the location corresponding with the MHz/kHz knobs, the resistor networks are matching. If the resistance is not matching, the mechanical brake is deactivated and the servo motor is powered to move the mechanical filters to the desires position. The mechanical filter movement is only done per MHz. The frequency reach is split in two banks. When the filter reaches it's end, the mechanical parts move to the other end to use the other bank of the mechanical filter.
This video is some years old an was rediscovered in 'the arcives'. Maybe this is interesting to have seen. ;-)

Видео SEM25 army radio mechatronics (archive video) канала polytech_nu