Some follow-up information:
I've tested the pin-outs per the troubleshooting section on the bottom of the Opti-pac web page (
http://www.ultimarc.com/optipac3.html) and the Happ output is definitely different than the output from another vendor's spinner or trackball.
Using a voltmeter, I could see on an Oscar spinner that the two outputs varied between 0 and 4.5 volts as the spinner was turned (and the second output would be somewhat the opposing value - e.g. one would read 3.7 and the other would read 1.2 or vise versa).
On the Happ optical board, one output would constantly read close to 0 volts and the other would hold 4.5v high and would temporarily drop to 0 volts as the sensor wheel turned. It would never stay at 0 volts - it was just an temporary change and would then jump back to 4.5 volts even though the wheel was not moving.
I ended up using a voltmeter to measure values on the pins coming directly off the optical sensor component on the Happ board and these were showing the expected voltage ranges as the wheel was turned, so I ended up just directly soldering the output wires to these pins on the sensor and connected them to the Opti-Pac. I then jumpered the Opti-Pac to use "Active HI" on the rotary inputs and everything now works ok.
It seems a bit odd I had to do this. Is the Happ board A052-0111-00 not directly compatible with the Opti-Pac? From what I've read, other people just wire the Happ board to the Opti-Pac and it all works with no problems.
The Happ board has a lot more components than the optical sensor boards used with my Oscar spinner and Ultimarc trackball, so I assume it must be sending out a different signal for a reason.
Brian