The tune box.
pa0nhc 20200611
C) The use, publication, copy and modification of all info on this site is only permitted for non-commercial purposes, and thereby explicitly mentioning my radio amateur call sign "PA0NHC", as the original writer / designer / photographer /publisher. (C)  

I have no photo of the present situation. This is an old photo.
The tuning capacitor is now directly connected to both loop N connectors.
Not used anymore are :
The coax ferrite cores, the transformers, the leakage resistor chain, and the 5pF balancing capacitor (5cm RG214).

A little 12Vdc motor with internal 3000:1 gearing (MFA 3000:1) can be fed from a small power supply. The motor itself and its DC drive lines are floating from ground, to make bi-directional rotation by the use of a simple manual looptuner possible.

The second 10 : 48 tooth belt reduction uses aluminum tooth wheels, and a rubber tooth belt. I used a belt without steel reinforcement. But as the shaft of the tuning capacitor is at neutral level, a steel reinforced belt is also useable. The big tooth wheel needs an 16mm to 6mm shaft adapter, to fit onto the capacitor shaft. After removing the flanges of an extra ordered 10 tooth wheel, it can function as an 16 to 6mm  adaptor.

The total reduction is adequate for use on the 80m band. In my case, the remaining slag is only e few kHz on 80m.

The tuning capacitor is mounted onto an L-shaped Trespa (or Plexiglas) bracket. This bracket can be shifted side wards to adjust the belt for minimal slag and tension.

The motor is mounted onto a stiff piece of Trespa, screwed onto a side wall. This stiffens the side wall, prevents bending, and enables a fully closing lid. As the motor bracket is a bit thin, the back end of the motor is supported by gluing a little block between the motor body and the bracket. 

A double sided PCB contains the filtering of the motor and DC lines, and a 12V / 5W heater (4x 120Ohm / 2W parallel), which is effectively preventing condensation in the cabinet

All lines in this tuning box are electrically floating.