Re: Damaged Selectron carrier wanted

[P3D Steve Spicer <s.spicer@xxxxxxxxxxxxxxxxxx>]

From: P3D P3D E R Swanson  <ers@xxxxxxxxxxxxxxxxxxxx>

>I've been told that you can't convert a TDC Selectron carrier to 7p. If
>anyone has a broken one they'd part with for free or extremely cheap, I'd
>like to try some experiments to disprove this, and post the results to
>listserv.


Hi Elliott

I can categorically say that it _is_ possible to convert the TDC Selectron
changer to 7 perf. I have not done the work myself, but a fellow Club
member recently bought one, modified it for 7-perf operation on his
TDC-716, and projected the Southern Cross Stereo Exhibition with it most
succesfully.

I had a look at the modified unit, and it appeared to me that the problem
to be overcome is making the shutter system within the carrier blank-out
the light from the lamphouse when a 7-perf-slide is being moved into and
out of the gate. (As you may know, the shutter system open or closes when a
slide is inserted or removed from the gate respectively.)

In particular the left hand side of the gate (when used on a 716) needs
special modification to get proper light blocking. The unit I saw had a
secondary shutter blade built into the left hand side of the gate. Partial
opening (or closing) of the shutter resulted in only one of these blades
moving, but as the shutter slid open (or closed) more and more, the
secondary blade would also move - a bit like a "telescoping" effect.

The modification I saw gave proper light-cut off that was the same on the
left and right hand side, so no stereo-rivallry occured when moving slides
into or out of the gate.

Hope these clues help.

Steve Spicer
Australia






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