[Collins] 75A-2 Switch Needed

[Gerald]

On Tue, 2005-07-26 at 07:54 -0400, Jim Walker wrote:
> I am working on a 75A-2 receiver.  The "OFF LIMITER CALIBRATOR" switch
> is destroyed and I need to find a solution.  The switch is unique.  It
> is a rotary, two section three position and has B+ on the switch for the
> Calibrator position.  The switch has to have an extremely low profile to
> the front panel or the rear of the switch is pressing on the frequency
> drum plastic coated dial cord risking cutting the cord from abrasion or
> shorting the B+ on the switch.
>  
> Anyone know of a suitable substitute, parts receiver with a pull out for
> sale, or creative solution?
>  
> Thanks,
>  
> Jim 
> KZ5AW
I envision the original switch to be made of brown phenolic, mostly
rectangular with 2 terminals in the plane of the phenolic on one end and
two on the other end. Probably the phenolic fixed piece 3/4" wide by
1-1/2" long.

As far as I can tell from checking three catalogs, they don't make them
that way anymore.

In the Allied Electronics catalog the Electro-Switch series D2D switch
seem to come closest as a replacement switch. Probably a D2D0206N for 2
poles adjustable 2 to 6 positions single section. Catalog number
747-0703. Sit down now, price $27.85. Used to buy pieces from Cinch for
no more than a couple bucks.

Another possibility is the series C4. Specifically a C4C0206N-A, catalog
number 747-6690. For $10.07.

I've not looked at any website to see if these switches truly have 1/4"
shafts with 3/8" bushings, the printed catalog doesn't say. They kind of
look like the might. Their terminals are in the plane of the switch, not
sticking back and whether they will fit under the dial cord depends on
the thickness of their detent mechanism.

All of the import rotary switches I see use a construction that puts the
terminals on the back and sticking further back, incompatible with the
dial cord.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer