Bird cage + paddle board = kludge

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While troubleshooting a piece of equipment, I encountered a bird cage and a paddle board. The “bird cage” consisted of a 24-pin DIP wire-wrap socket, most of whose pins plugged into an IC socket, which in turn plugged into a socket on a circuit board. A few of the pins on the wire-wrap socket had been trimmed short and replaced with resistors soldered in series with the contacts of the lower socket. Leads from a couple of capacitors stretched from pin to pin.

A few lengths of wires snaked down the side of the bird cage to join a matchbook-sized paddle board that sported a pair of ICs and a few passive components. A blob of hot-melt glue secured the paddle board to the main board. Time and financial pressures no doubt inspired the add-on circuits, which the designer presumably fixed on the board’s next spin cycle. Fortunately, the equipment failure didn’t involve this kludge.

The “kludge” enjoys a long and somewhat checkered history as a fix for a design flaw, or as a rapid implementation of a customer-requested feature. During World War II, the vacuum-tube industry diverted most of its production capacity to the war effort, forcing domestic radio repair techs to scramble for replacement tubes. Replacing and rewiring a tube socket to accommodate an available tube posed problems, and JFD Manufacturing devised the Sockette to adapt an available tube to fit a hard-to-find tube’s socket.

Nowadays, IC manufacturers render older or slow-selling DIP ICs obsolete by cranking out new products at a dismaying rate. If you’re faced with replacing an obsolete IC, use any Web browser to search for the part number. Be aware that counterfeit and rebranded devices exist, so choose sellers with care. You can also use modern versions of the Sockette. For example, e-PBoard Design, Interconnect Systems, and Aries Electronics offer custom and off-the-shelf products that convert almost any component’s footprint to another.

Whether you test other peoples’ equipment or build your own test fixtures and accessories, sooner or later you’ll get a chance to practice—and appreciate—the fine art of kludgery. While necessity may give birth to the occasional invention, more often it delivers kludges.

brad@tmworld.com