Got some old Cathode Ray Tubes laying around and wonder whether they’re still any good? Want to test some other high voltage devices laying about the man cave/lab/workshop and nothing convenient to hand? Look no further! This marvelous gizmo will allow you test a whole range of electrostatic CRT’s, including those with PDAs (Post Deflection Acceleration). The basic design includes the following:
- CRT heater supply limited to about 6W:
- 6.3V at 0.6A
- 4V at 1.1A
- 2.5V at 2A
- Grid voltage adjustable from -5V to -120V w.r.t. the cathode.
- Focus anode voltage adjustable over a wide range.
- Acceleration anode voltage selectable up to about +2kV w.r.t. the cathode.
- PDA voltage selectable up to about +5kV w.r.t. the cathode.
- Deflection plate voltage difference from -300V to +300V.
- Adjustable deflection blanking, acceleration anode and other electrode voltages.
- AC coupled inputs to the X and Y deflection plates and grid modulation (Z axis).
- Driven by a 12V DC supply, minimum 2A, either bench supply or custom PSU.
- Provision for current and voltage instruments.
Safety First! This device produces some very high voltages, is not intended for commercial purposes and should only be built or used by those experienced in using such devices.
There are a number of options. You can build it from a kit, the electronics is available from the great minds at Sgitheach (here) and the case/hardware is available from this website (see price list). Completed and tested units are available upon request, but be warned that they take sometime to put together. We only use the correct voltage rated wire and banana plugs to ensure safe operation. The tester can be operated using a bench power supply or there is also a purpose built PSU with an auxiliary 15V switchable outlet too (available as kit or pre-built)
There are also a number of ‘extensions’ to the tester to allow, well, testing of E1T tubes, Dekatrons (octal varieties, such as GC10B, OG4 etc.) and even NIMO tubes!
