Hello MMD.  This question is addressed to that tiny fraction of members
who have some experience with a Half Duo-Art that has a Temponamic
control.  Andy Hood tells me that his has not.  The tubing chart
available from the British PPG does not help here.

Their diagram illustrates a rotary D-A On/Off switch; mine has a wooden
slide switch that is ingeniously ganged to a Pedal Control On/Off slide
switch.  Andy's piano is an American Steck; mine was made in the U.K.
However, the expression unit in mine is identical to a salvaged one
given to me by an AMICA member in Denver about 25 years ago.

(I think his name was Richard and I think he earned part of his living
by playing the piano on either a tourist steam train or a tourist
riverboat.  I wish I could remember his full name because I'd like to
tell him that all those spare bits have been very useful.  Pulling them
apart has given me a lot of insight into what is supposed to happen in
my player.)

The tube from the Sustain port on the tracker runs through the On/Off
switch straight down to the Sustain nipple on the Power Governor for
the two pedal pneumatics.  The tube from the Soft Pedal port on the
tracker bar runs through the On/Off switch too, but down near the Power
Governor there is a Tee.  One branch heads off to the Soft nipple on
the Pedal Power Governor, as one would expect, but the other branch
heads up to a pallet valve on the curious excrescence that is attached
to the outside of the main expression unit, with its single set of
accordion pneumatics.

(OK: perhaps the only curious thing about the excrescence is that,
unlike all the other wooden pieces in the lower player action, it is
unpainted.  It is in fact controlled by the Temponamic lever.)

However, the tubing from the tee onwards has a distinctly non-Aeolian
look to it.  It wanders around unnecessarily, is of a smaller diameter
than the tubing preceding the tee, and at the Pedal Power Governor it
is pushed into the soft nipple because it is too small to fit over it.

My question is;  does anybody have any idea if this is how the Soft
Pedal control is supposed to be tubed?

John Phillips in Hobart, Tasmania

 [ Your benefactor in Denver might be Dick Kroeckel of Arvada,
 [ Colorado.  He's a fine pianist and player tech and is active
 [ with AMICA.  -- Robbie