Odd item found

[jr_tech]

Originally Posted by old_coot88

In order to produce multiple bars, it'd hafta run at some multiple of the line frequency. Seems like that would require an active device of some kind. Tunnel diode maybe?

Perhaps a neon bulb???

This is a fun puzzle!

jr

[wa2ise]

Originally Posted by Tom Albrecht

How does it manage to sync anything with the sweep?

If the TV is tuned to a station, the vertical would be synced to 59.94Hz vertical sweep. A 60Hz waveform injected into the CRT would slowly crawl up the screen, slow enough so you could adjust the vert height and linearity.