Ball variometer antenna for 40m - 80m band, remote controlled

Our radio friend Klaus DJ2ZK still had a ball variometer from military stocks at home. Frank DL6FH and i, DK4WN, had the idea of installing this ball variometer together with an MFJ-1979 antenna with a 5m length as a base loading antenna. The ball variometer has an inductance of 5.7 uH - 72uH and was therefore ideal for the bands from 40m - 80m. In addition, the plexiglass housing should be illuminated and change the color of the lighting to red when sending. For this we have coupled out the HF with high impedance on the ball variometer, rectified it and amplified it with a transistor. The transistor switches a relay which then switches from white to red. The antenna works from 40m - 80m without tuner with a SWR ratio of 1: 1.0. The ball variometer is remote controlled.
Here is the video of our ball variometer conversion.