In MMD Digest 98.09.12 Dick Merchant asked for pictures and info about
the Duo Art Transposing Tracker Bar.

I have never had a use for it other than playing with the key of the
song. I understand that the Weber was custom built for a singer but I
have nothing to support this. The tubing is brittle and shifting them
with the tracker might cause failure.

When shifting to the right the top 4 playing notes are cut off.
Likewise, when shifted to the left the bottom 4 playing notes are cut
off.

Picture 1  Shows the Tracker Bar with the shifting quadrant at the right
side of the spool box.

Picture 2  Shows more of the shifting quadrant and the control valves.

Picture 3  Is a closeup of the lever to the tracker bar and the two
control valves.

Picture 4  Shows the valve boxes that cut off the treble or bass notes

 [ I'll put these pictures temporarily on the MMD Pictures page
 [ before the end of the day:
 [
 [    http://mmd.foxtail.com/Pictures/
 [
 [ However, when Robbie gets back we'll probably move them to a
 [ new "Technical Information" page.   -- Jody