Pearl Box Plans by the Jolly Roger

The Pearl Box:Definition - This is a box that may substitute for many boxes

which produce tones in hertz. The Pearl Box when operated correctly can

produce tones from 1-9999hz. As you can see, 2600, 1633, 1336 and other

crucial tones are obviously in its sound spectrum.


Materials you will need in order to build The Pearl Box:


C1, C2:.5mf or .5uf ceramic disk


Q1.....NPN transistor (2N2222 works


S1.....Normally open momentary SPST


S2.....SPST toggle switch

B1.....Standard 9-Volt battery

R1.....Single turn, 50k potentiometer

R2..... " " 100k potentiometer

R3..... " " 500k potentiometer

R4..... " " 1meg potentiometer

SPKR..Standard 8-ohm speaker

T1......Mini transformer (8-ohm works


Misc....Wire, solder, soldering iron, PC

board or perfboard, box to

contain the completed unit,

battery clip


Instructions for building Pearl Box:


Since the instruction are EXTREMELY difficult to explain in words, you will

be given a schematic instead. It will be quite difficult to follow but try

it any way.


(Schematic for The Pearl Box)


! ! \

C1 C2 \

! ! +

+ + -----+T1

!\ +------------+-+

! b c-------! +

! Q1 ! +-S1-

! e-----S2---+ ! SPKR

! ! ! +----

! B1 !

! ! !

! +-------+

!R1 R2 R3 R4!

/\/\ /\/\ /\/\ /\/\

+--+ +--+ +--+

Now that you are probably thoroughly confused, let me explain a few

minor details. The potentiometer area is rigged so that the left pole is

connected to the center pole of the potentiometer next to it.

The middle terminal of T1 is connected to the piece of wire that runs down

to the end of the battery.


Correct operation of The Pearl Box:


You may want to get some dry-transfer decals at Radio Shack to make this

job a lot easier. Also, some knobs for the tops of the potentiometers

may be useful too. Use the decals to calibrate the knobs. R1 is the knob

for the ones place, R2 is for the tens place, R3 if for the hundreds

place and R4 is for the thousands place. S1 is for producing the all the

tones and S2 is for power.

Step 1: Turn on the power and adjust the knobs for the desired tone.

(Example: For 2600 hz-


Step 2: Hit the pushbutton switch and VIOLA! You have the tone. If

you don't have a tone recheck all connections and schematic.