When did the 122XB model come out?

[David Anderson]

I don't see many of these, so I was surprised when one came in that was built in 1995. For some reason, I had thought they were a more recent model.

[enor]

I don't see many of these, so I was surprised when one came in that was built in 1995. For some reason, I had thought they were a more recent model.

If I recall right, they came out together with the XB-3 (thence the "XB" in their model designation)

[David Anderson]

If I recall right, they came out together with the XB-3 (thence the "XB" in their model designation)

And not the XB-2 in 1991?

What's odd to me about the 122XB is that it has two discrete DC supplies on the motor control board. One is the usual always-on supply that allows remote On/Off switching, while the other is the somewhat ill-conceived use of 6550 cathode current for the motor speed control circuits. While I can understand why they wanted to have one circuit board with or without add-ons for different models, it's not the most elegant solution.

The motor board, IMO, should have had its own independent DC power supply from the get-go.