[ Scotty Greene wrote in 191217 MMDigest:  

> Is the actuation [control] lock and cancel?  Hole #1 on the Style
> 153 tracker bar is "Swell Shades Open".  How do they get closed?

I believe Scotty Greene is right in thinking that the swell shades
control on a Wurlitzer 153 band organ is a lock-and-cancel system.

I once owned a Wurlitzer 146-A band organ and I added to it a set 
of swell shades, using hole no. 1 in the 150 tracker scale, which is 
labeled by Wurlitzer as "swell shades open," to open the swells, and 
hole 4, which is labeled "cancel," to close the swells, operating my 
system by a simple lock-and-cancel valve set running off the organ's 
vacuum supply.

The hole labeling I refer to above is that given in the Wurlitzer 
150 scale printed in "Treasures of Mechanical Music", by Art Reblitz 
and Dave Bowers.  Matt Jaro has a Wurlitzer factory blueprint dated 
9-29-21;1-26-30 in which hole 4 is labeled "all off."   In that 
blueprint, hole 1 is labeled "E for trumpet-on."  The meaning of  
that "E" is unclear to me, but hole 4, which is labeled in the Reblitz-
Bowers scale as "Piccolo and melodie violin pipes on" is on the Jaro 
blueprint labeled as "E for melodie on"; so I don't think the "E" has 
any real significance here.

My swell shades were opened and closed by a simple vacuum-operated 
pneumatic, using the same setup as is used in the Wurlitzer 165 swell 
shade system.  While the swells are actuated by a vacuum pneumatic 
(or two pneumatics, depending on pneumatic placement), the pneumatic 
merely opens the swells, which normally remain closed due to their 
springs and the rods connecting each slat of the six slats in each of 
the two shade sets (right and left) to the other slats in the same set.  
(Whew, I hope this is clear.)

The lock-and-cancel-operated vacuum pneumatic merely counteracts the 
spring tension keeping the swells closed in order to open them.  In 
one 165 band organ I am familiar with, the pneumatic is mounted on the 
stationary center post of the swell shade opening and exerts its force 
on two metal fingers, each screwed to the one swell slat in each swell 
set which is closest to the center post.  In another 165 I am familiar 
with, there are two separate vacuum pneumatics, mounted to the right 
and left sides of the swell shade setup, each one pulling one of the 
two swell shade sets to open position by a connection with the rod 
controlling that shade set.

I realize that pictures would be a lot clearer than my wordy 
descriptions, but this is the best I can provide today.

Wurlitzer's placement of the vacuum pneumatic and the way it operates 
the swells is not at all complex, but that's Wurlitzer: often a bit 
different but with good results.

Matthew Caulfield
Irondequoit, New York