221: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 3: | Line 3: | ||
a maintenance issue). It has a transformer-coupled trigger circuit which | a maintenance issue). It has a transformer-coupled trigger circuit which | ||
would seem to preclude DC level-based triggering. The trigger circuit uses a | would seem to preclude DC level-based triggering. The trigger circuit uses a | ||
[[1N3713]] 1mA [[tunnel diode]]. The vertical output amplifier that drives the | [[1N3713]] 1mA [[tunnel_diodes|tunnel diode]]. The vertical output amplifier that drives the | ||
CRT plates is two opamps made from discrete transistors. One drives the top deflection | CRT plates is two opamps made from discrete transistors. One drives the top deflection | ||
plate and the other drives the bottom plate. | plate and the other drives the bottom plate. | ||
* [http://manoman.sqhill.com/pdf/tek-221.pdf Tektronix 221 Manual (PDF)] | * [http://manoman.sqhill.com/pdf/tek-221.pdf Tektronix 221 Manual (PDF)] | ||
Revision as of 10:13, 9 May 2011
The Tektronix Type 221 is a miniature 5MHz analog scope introduced in 1973. It has a switching power supply and built-in rechargeable batteries (which are a maintenance issue). It has a transformer-coupled trigger circuit which would seem to preclude DC level-based triggering. The trigger circuit uses a 1N3713 1mA tunnel diode. The vertical output amplifier that drives the CRT plates is two opamps made from discrete transistors. One drives the top deflection plate and the other drives the bottom plate.