Universal Cable Adapter (Feb, 1960)

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Universal Cable Adapter

By Art Trauffer

Built into a typewriter ribbon case, this adapter permits over 50 combinations of cable connections.

WHEN the writer finished making this adapter he started to count the different combinations of connections that can be made with it, but when he reached 50 he gave up. Certainly, 50 is not the limit for this versatile and easily-made adapter. If you build one of these you will save much time and trouble when joining together various types of connectors in radio and electronics experimental and test work.

To provide a degree of shielding, the adapter is built in a 2-1/2″ by 1″ metal container for a typewriter ribbon, but any similar metal container with a friction lid will do. The enamel coating on the outside of the container was removed with sandpaper and scouring powder.

The illustrations show how the two 5-way binding posts, and five of the jacks, are mounted in a circle on the friction lid. The “Tiny Jack” is screw-fastened in the center. The exact placement of the parts is not critical—just arrange them for convenience and good looks. Instead of drilling the mounting holes the required size, the writer found he could do a neater job by drilling small holes and enlarging them to the required size with rat-tail files. However, the four small holes for the “Tiny Jack” are easily drilled as required— use a No. 44 drill for the two mounting screws, and a No. 31 drill to clear the two pin holes in the jack.

All of the parts are wired in parallel, and the wiring is simple because the “ground side” of most of the parts are automatically connected together when the parts are mounted onto the metal lid of the can. If the inside of the metal container is coated, be sure to scrape the metal clean at the places where the parts are supposed to contact the metal lid.

If your metal container isn’t quite deep enough when the container is closed, simply raise the friction lid a little and then solder both parts of the can together with some solder spots.

PARTS LIST

2 5-way binding posts.

1 single-hole mount phono pin jack.

1 standard microphone chassis connector.

1 miniature microphone chassis connector (Switchcraft).

1 standard open circuit phone jack.

1 miniature phone jack 1 “Tiny Jack” (Lafayette MS-284) 1 round metal container with friction lid about 2-1/2″ wide and 1″ deep. (Carter typewriter ribbon case or equiv.) 2 2-56 or 2-64 round head machine screws long with hex nuts for “Tiny Jack” Misc.—Few assorted lockwashers, few inches #22 hookup wire

6 comments
  1. Richard says: December 1, 20112:03 pm

    That’s actually a fairly clever idea. I may just build something similar, but with an updated list of the connectors I actually encounter (never heard of a “Tiny Jack”). I might use an altoids tin to make mine.

  2. Stephen Edwards says: December 1, 20112:31 pm

    Pretty good; over half of these connectors are still in common use (although what’s a “Tiny Jack”?)

    I’m not sure how he gets 50+ combinations. There are seven different connections, so if you consider pairs only, there are 7 * 6 / 2 = 21. All combinations including two or more connections is 2^7 – 7 – 1 = 120, although I don’t see how useful a five-way cable would be. Perhaps he was counting the five-way binding post as five different connector types.

  3. Mike says: December 1, 20116:29 pm

    I was thinking there would be plenty of hum added to the line.

  4. Toronto says: December 1, 20117:59 pm

    Stephen: yeah, that would give 11*10/2, or 55 pairs of connections (counting spades, alligators, bananas, etc separately.)

    “Spades, Alligators and Bananas” is a *terrible* name for a rock band, by the way.

  5. George says: December 2, 20115:19 pm

    The Tiny Jack is a 1/8 inch (3.5 mm) phone jack, the 3/32 inch (2.5 mm) jack was called the Teeny Jack — I think it was Switchcraft that sold them under those names first.

  6. Gary James says: December 10, 201111:06 pm

    A pair or more of alligator clip cables does me, for non critical signals and power anyways.

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