For the 'eyes' of the Senster two HP doppler units were used, with custom made antenna horns. This system worked on 10 GHz. This is one of these units.

The HP doppler module type 35200B/001 with custom made antenna horn (gold plated)

The HP doppler unit in close-up. It is very old, as you can see it has a very low serial number.

In the box we also found this test doppler receiver

The HP doppler unit as seen on the Senster

Another collector kept one of the potentiometers of the Senster. With this part the computer could measure in what position one of the joints of the Senster was. The brand of the potentiometer is Penny and Giles, type PGS LP21/85. It is 45 cm long and 35 mm diagonal.

The inside of the potentiometer.

This drawing of the Senster was found near the meter.