[Collins] Collins 718T

[Dr. Gerald N. Johnson]

On Mon, 2007-07-16 at 13:33 -0700, Glen Zook wrote:
> The engineering, as far as I know, on the amateur line
> was still being done in Cedar Rapids.  However, the
> Industrial Design group was assigned to do the cabinet
> design.  Since that group really didn't "fit" in any
> of the regular Collins engineering sections it was
> assigned as the 13th CCU of Process Division in
> Richardson.
> 
> Process Division, at least in the 1967 through 1969
> time frame when I was employed by Collins Radio, was
> primarily responsible for the manufacture of circuit
> boards, thin films, and thick films.  Also, the Dallas
> Region Photography Laboratory was assigned to Process
> Division (was on the main floor of Building 402). 
> Harry Passman was the vice president of Process
> Division during that time.
> 
> Glen, K9STH
> 
All the etched circuit stuff in the 821A-1 was special generally on a
thick teflon substrate as special coupling capacitors. Then they had to
be machined to remove the stuff that made the copper stick because it
was a bit conductive. A production quantity of 9 didn't much justify
etched circuits, though I had 9 identical circuits with a multiple pole
push button and a 4 pole relay in the servo section of my diagnostic
panel, and that many etched circuits might have paid off, but in the
whole scheme of the project the pennies saved wouldn't have been very
significant. When I drew the schematic, I drew one section then copied
them onto velum and assembled the rest with scotch tape. I started out
on the 821A-1 in Cedar Rapids and finished it at Dallas. Much of the RF
fabrication that was initially designed in Cedar Rapids was still done
in Cedar Rapids after the engineers moved south, but I think what
finally went out the door except for my diagnostic panel silk screening
was done in Texas. Some modules were wired by pilot line girls but in
our laboratory and often finished by me and a lab tech on Saturday for
installation on Sunday for testing on Monday. Texas division couldn't
take the text artwork for my parts and make them legible. Cedar Rapids
could take the same artwork and make panels that looked like they'd been
run on a offset press. We tried to get a Dallas commercial silk screener
to try them but they couldn't do the size or the quality we had come to
expect from Cedar Rapids.

When my first silk screens got to the paint shop in Cedar Rapids, the
shop foreman called me up to complain that there were no positioning
tolerances on the drawing. I told him the silk screen would fit the
panel and its many switch button holes perfectly and he didn't believe
me. So I trotted back to the paint shop and showed him by aligning the
silk screen with the holes. We had cheated, since the wiring was simply
point to point or switch to switch, there was nothing behind the panel
to require a switch location so we measured the artwork. In fact at last
some early panels we took a spare positive transparency to the model
shop and taped it to a panel and had them center punch the hole
locations through the cross hairs on the transparency. I can still
remember the clang as Arnie Spielbauer demonstrated with sturdy center
punch and 2 pound hammer. Saved a couple days and got superb accuracy
that way. Later panels were punched on a CNC punch from coordinates
measured from one of those transparencies. The T squares in the art
department were all bowed more than a 1/8" bow which prevented their
artwork from matching a mechanical drawing.

An industrial design group cabinet, half a continent away from the
circuit designers wouldn't seem to me to be the smartest of moves, but
then Art did run his own commuter airline that we used heavily at times
between Cedar Rapids and Richardson. Twin Beeches to Convair. Though I
don't think Art ever rode the Twin Beeches.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer