Fig. A: Components clipped together for initial testing.
Fig. B: Mics extended from listener PC board.
Fig. C: The listener and transmitter share connections to
the battery pack. Fig. D: Cut through the pages to hollow
out the book.
GUT AND EXTEND PREPARE THE BOOK
Shed the extra bulk by unscrewing the listener and Choose a hardcover book that’s big enough in all 3
transmitter’s plastic housings and taking out their dimensions to enclose the system’s components.
guts. Note the locations of all the controls: on/off, The dust jacket should be in good condition. Pick
volume, balance, tuning, and so on. Hook everything a title that won’t draw undue attention from your
back up with jumper cables, drawing power from intended target. You don’t want them to notice the
2 AA batteries in a holder (Figure A). Test again. book and start looking through it!
I decided to move the listener’s 2 microphones from Skip a few pages and set your components
their original position to the book’s outside spine, centered side-by-side on a front-facing page. Draw
because the spine is generally exposed whether the a rectangular outline of the components with a ruler,
book is in a bookcase or just laying around. adding ½"– 1" all around, making sure there’s still
To do this, desolder the mics from the PC board, ½"– 1" of book left around the edges. This outline
being careful not to damage them or any nearby will become your compartment. Cut a piece of
electronics with too much heat. Use hookup wire to cardboard about ¼" smaller all around, to serve
extend the leads of both mics by about 6", and resol- as the compartment’s floor.
der the extended leads back to the board (Figure B). I used an X-Acto knife and a ruler to cut the rect-
While you’re at it, extend the power leads from angle through the pages, cutting down about
the transmitter and listener by about 6" as well. each time and stopping within ¼" of the back cover.
Protect all the new connections with heat-shrink I used a binder clip to keep the cut pages out of the
tubing (always slip it on before soldering). Attach way while I worked downward (Figure D).
the power leads from the 2 components and the Two previous MAKE articles also describe
battery box, joining all the reds (positive) and all the book-hollowing techniques: “Palm Pilot Notebook”
blacks (negative), as in Figure C. Twist the conduc- (Volume 07, page 138) and “Uncle Bill’s Magic Tricks”
tors together, solder, and cover with heat-shrink. (Volume 13, page 60).
Photography by David Simpson and Linda Kennyhertz; Sam Murphy (H)
90 Make: Volume 16