Stabilovolt STV280/40 dismantled

This device is a gas-filled voltage stabiliser with multiple anodes. It can thus produce multiple outputs, typically for the STV280/40 these are 280V, 210V, 140V and 70V, representing 70V per section.

The outer connecton can be seen here. It connects to one of the pins in the base via a wire to the glass tube that can be seen in the centre of the photo.

Note that the CV data (STV280/40 = CV1068) lists the electrodes as cathode and anode 1 thru 4, but the Stabilovolt literature lists these as -C, 0, +B1, +B2 and +B3. The same literature shows the device in circuit with the cathode at -70V, anode 1 at 0V, 2 @ 140V and 3 @ 210V. This shows the flexibility of the device.

Anode 2 removed revealing anode 3 (or +B2). Again the wire connecting the remaining anode to the base can be seen at the bottom of the picture.

Anode 3 removed, revealing anode 4 (or +B3). This inner anode is now all that is left.

The connecting wire for the inner anode is taken through the top and down an insulated tube inside.

Here are all the component parts, except the base and glass! Dimensions of the various anodes are as follows: