Numitron Clock

As everything was connected up and the power was switched on there was a faint whine coming from somewhere in the circuit. I figured the Numitrons were causing some power fluctuations so I added a 100uF capacitor on the power rail. The whining stopped.

The power supply module I have already has capacitors but they didn't seem to help here.

The first prototype had a potentiometer which acted as a selector between the clock's different view modes. I replaced that with a rotary encoder as it has unlimited range and avoid the potentiometer's unwanted behaviour of hovering between two states.

Soldered the numitrons to separate boards with small screw connectors. This should make connecting them a bit easier and also make replacing a tube possible in case a filament burns out.

Received the field telephone and it looks like a good fit for the Numitrons and the electronics. As it's military hardware it's very easy to dismantle without breaking anything. I'll just remove everything except the case itself and make a new top which houses the tubes.

Instead of doing some woodworking I decided to try to make the casing out of an old field telephone. Its bakelite housing should make a really nice-looking retro case with some modifications.