Replacement Cursor Control for Tektronix 2230 Oscilloscope


If you have been lucky enough to pick up a Tektronix 2230 Oscilloscope off Ebay,
you may have been unlucky enough to get one with a defective cursor control.
A24 Cursor control Board Pt No. 670-9701-00
Dual 10K Pot plus Switch Pt No. 311-2285-01

I have a collection of these with various fails, no switch, sticky switch, jerky pots, no pot action, noisy action.
All of which essentially make the measurement function void.
I looked for replacements but apart from risking another scope purchase for parts these controls are no longer available.

SO.......an alternative:

This design uses a Bourns optical encoder, microprocessor and dual D/A to exactly mimic the original function of the cursor control.
It operates exactly as the original, press the knob for cursor change and menu select.

Technical details :
64 pulse encoder, circuit clocks on both edges so 128 pulses per revolution.
Dual 8 bit DAC counts to 1024 pulses for each cursor

I don't think you can tell the difference between this and the original part, sensitivity and accuracy is identical and in my opinion more stable.
The 2230 does have a tendency to lose track of the cursors once in a while,thats a design glitch, this won't cure that.

 Installation is simple, does require an extra  5 Volt pick off from the board.

Limited quantity available

Video

Broken encoder new encoder 1
new encoder 2 new encoder 3
board view boardview 2
board view 3 board view 3