Re: (OT) Curious about DuMont Type 233 Giant Screen Oscillograph

Scott Scheirman

Off topic continued:

"Convert TV into sensitive, big screen oscilloscope. Only minor changes needed"
Thanks for the reminder.
As a teen (14?), I purchased the instructions, and converted several black and white CRT TVs into oscilloscopes.
One was perhaps 12" diameter, another was 19" or so. Some were as large as a dishwasher.
While they were (obviously) not anything like a modern scope, they did open up a new world to me.

Caution: do not try this at home. I may have forgotten some (many?) steps.

* remove the horizontal sweep wires from the yoke, and connect them to a spare yoke
* this helps ensure the high voltage continues to work
* find a spare filament transformer (120 volt to 6.3 volts)
* connect the primary ("120 V") of that filament transformer to the horizontal terminals on the yoke that is on the CRT
* connect an audio amp to the 6.3 volt winding of that transformer
* yes, you can possibly use the audio amplifier of the TV
* rotate the yoke 90 degrees (thus, the vertical sweep became the horizontal sweep)


Again, don't try this at home!

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