TV experiment in 1938

[ppppenguin]

By 1938 I would have thought that mechanically scanned TV was obsolete. This fearsome looking scanning disc was used by Bell in the US as part of a long distance co-axial cable system.
https://archive.org/details/bellsystemte.../2up?q=445

The CRT at the receiving end is also a bit of a brute.

[Murphyv310]

Imagine that CRT imploding...... At the proximity of the man holding onto it I'd not like to see the mess it would make of him. Scary stuff you find Jeffrey.

[joebog1]

That CRT would have very fine focus however.
The pictures would have been very clean.

Joe

[LENINGRAD T2]

In those days, the determination of scientists was enormous. They often risked their health and lives to complete their beloved research project. Today, there are bioethics committees and no one could come close to such a monstrous CRT. Designing such a picture tube and creating a vacuum in it was a big challenge.

[ppppenguin]

The rotating disc scanner is dangerous too. If something breaks while it's spinning you don't want to be in the way of the fragments.

[BusyBee]

That CRT is well on the way to being one of the first particle accelerators for CERN

Tracy

[Panrock]

The rotating disc scanner is dangerous too. If something breaks while it's spinning you don't want to be in the way of the fragments.

Exactly the sentiment I have with my stainless steel 44lb 120-line mirror screw, which rotates at 25 Hz. Although it's unlikely to fall apart, if one of its bearings locked up when in motion, it would cause mayhem.

Steve

[Geordie McBoyne]

Wasn't a mechanical disc scanner made to produce 405 line sync pulses? Large disc spinning at 1,500rpm!

Geordie McBoyne.

[ppppenguin]

I think that was a small disc, rather like a Hammond tone wheel organ.

Hammond wasn't the first company to use tonewheels: https://en.wikipedia.org/wiki/Tonewheel

Now this is a serious tonewheel: https://en.wikipedia.org/wiki/Alexanderson_alternator