49 More Easy To Build Electronics Projects Kneitel
49 More Easy To Build Electronics Projects Kneitel
49 More Easy To Build Electronics Projects Kneitel
/ \ LJi 0
Li\g- 0,3
ELL.:rSTADJE__g0
2 13
"Black -Light" Projector
3 Unusual Musical Effects Device 15
4 Tilter Box Oscillator 17
5 Radio -Band Metronome 19
6 21
Winking Night Light
7 Electronic Chirper 23
8 Electronic Rifle Range 25
9 Electronic Fish Lure 27
10 29
Toy Telephone Amplifier
11 Coin Battery 31
12 Electronic Metal Locator 33
13 Perpetual Beeper and Meter Deflector 36
14 FM Wireless Transmitter 38
15 Neon -Bulb Wattmeter 42
16 Flashlight Radio Transmitter 44
17 Solar TV Reception Booster 46
18 Free -Power AM Radio Receiver 49
19 Electronic Stethoscope 51
20 Bathtub Overflow Alarm 53
21 Aquarium Heater Silencer 55
22 Electronic Tic-Tac-Toe 57
23 Fence Charger 59
24 Receiver Signal Alarm 61
25 Magic Magnet Box 63
26 Electric Combination Lock 65
27 Echo Box 67
28 Pool Splash Alarm
29 Wireless Mike
71
30 Automatic Animal Flasher
73
31 Long -Distance Light -Ciphering Machine 75
32 Adjustable Electronic Flasher 77
33 Matchbox Oscillator
79
34 FM Music Receiver
81
35 Transistor Tickler
83
36 "Chaos -Pandemonium" Box 85
37 Gypsy Light Organ 87
38
39
Hi-Fi Color Lights 89 Tips For The Beginner
Electronic Rainmaker 91
40 Do -Nothing Kiddie Box 94 If you are a beginner in electronics projects building, you would be
41 "Crazy-Lite"Attractor well advised to start with the simplest projects, i.e., those using
96
42 Match -Needing Electric Lamp neither tubes nor transistors. Recommended circuits are those
98
43 Junior -Size Tesla Coil 100 relying on, say, resistors, capacitors, batteries, and neon bulbs.
44 Electronic Thermometer for Liquids 102 First, you will need a good supply of hookup wire. For circuits
45 Portable Metronome 105 the power to which is supplied by 9 -volt and 221/2 -volt battery packs
46 Personal Electronic Dripolator 107 you can use any insulated hookup wire available. For higher -power
47 Electronic Siren 109 circuits in this book such as those supplied by 120 VAC, insulated
48 Telephone Buzzer Toy 111 line cord pulled apart is ideal. Always keep hookup wires as short
49 VLF Converter as possible, yet never so short as to create a danger of short-
113
Appendix A Substitution Guide 115 circuiting should the device be jarred or dropped.
Appendix B Component Color Codes 117 A pair of long -nosed pliers, a pair of conventional pliers, a
Appendix C Electronic Schematic Symbols 120 small screwdriver, a hand or power drill, and an assortment of
Index wrenches for installing nuts and bolts are highly useful.
124
Resistor values are indicated in ohms on the schematics and
are 1/2 watt unless otherwise specified in the parts lists. If you are
slow on determining resistor values from resistor markings,
consult the resistor color -code chart in Appendix B. If you do not
have a resistor of a certain required value, you may be able to
series or parallel connect other -value resistors (while observing
power requirements) to achieve the required value. Also, don't
feel hamstrung because you can't find, say, a 25K potentiometer;
chances are that a 35K or 50K potentiometer will work just as well.
Similar approximations to fixed -value resistors are also possible,
9
and a rule of thumb for resistor substitutions is always to exceed
the specified resistance; never go under it. In any case, keep the
substitutes close to the original values.
Although high -capacitance capacitors are usually typographi-
cally marked, most low -capacitance types are color coded. The
capacitor color codes are given in Appendix C. The "µF" types
used are usually tubular and their values are printed on the sides of
the capacitors. Electrolytic capacitors, which are used frequently,
also have a voltage rating, which is given in the parts lists but not
on the schematic diagrams. The plus sign on the electrolytic
capacitor symbol indicates the hot side of the capacitor. This side is
also indicated on the capacitor itself. Electrolytic capacitors
deteriorate with age, so be alert to this possibility of malfunction.
Batteries are also often used in the projects, since they supply
smooth DC and permit portability of the device. You should not
attempt, however, to power a tube -type device that makes use of W
relays and calls for 6 VDC with four 11/2 -volt microminiature
hearing -aid cells. Logic will tell you that a much larger battery pack Cigarette -Pack Flasher
will be required. Most transistor circuits, however, will perform
very well on small batteries normally used for powering semicon-
ductor devices. One of the most fascinating things in electronics that a person can
Most of the projects are made of ordinary components which experiment with is the neon bulb. Generally available for about 25
can be salvaged from worn-out household electronic gear. Thus, cents each (or less), the tiny NE -2 bulb is an interesting item. All
for maximum economy, you may cannibalize radios, TV receivers, that is necessary is a handful of capacitors and resistors, and you
hi-fi equipment, etc. when they are to be disposed of. Remove all will be blinking and winking in no time.
components-even tube sockets and switches. What few people realize about neon flashers is that, although
A substitution guide for transistors, tubes, and diodes, used in they generally require 90 VDC or more to "Fire," they draw so
this book is given in Appendix A. Standard schematic symbols are little current that large, heavy-duty 90 -volt B cells do not have to be
given together with their meanings in Appendix D. installed to get them to operate. A glance at Fig. 1 and Table 1 will
Heat is the enemy of all electronic components, be they illustrate this. In this instance, four 221/2-VDC hearing -aid bat-
capacitors, tubes, or whatever. If you intend to do a lot of teries are wired in series.
soldering, it would be wise for you to purchase a light -weight This amazing gadget, requires only three resistors, three
soldering gun or small soldering iron or pencil. You will need a capacitors, three neon bulbs, and the four -hearing -aid cells just
soldering tip which is long and narrow and which does not get described. The "chassis" will be an empty cigarette pack,
hotter than is necessary to melt the solder. When you get the more something, perhaps, on the order of the hardpacks. This will give
complex circuits using semiconductors, you will need to use a heat you a bit of near -cardboard support on which to mount your bulbs
sink to prevent heat from ruining the semiconductors. and a durable case for housing circuitry and batteries.
Keep a good supply of cigar boxes handy which can be filled Note that there is no on -off switch-it is unnecessary. All
with machine screws and nuts suitable for use in mounting three bulbs will flash alternately and in unusual patterns for periods
components and terminal strips. As an added feature, you will find of up to one year without requiring fresh battery replacement!
many projects that you can build right into the cigar boxes! (Incidentally, this gadget is a great toy for children.)
10 11
CIGARETTE PACK
r
Ml
-22? 2 -Q
"Black -Light" Projector
Here is a gadget that can be assembled in a couple of hours, yet will
provide endless hours of use on the job. If you are not familiar with
ultraviolet or "black" light, you are truly missing out on a
fascinating scientific phenomenon. Commercially, black lights are
used for chemical analysis, prospecting, and even criminal investi-
90V DC
gation. For our purposes, however, the amazing black light will
reveal curious colors and glows of ordinary household objects
which you would never suspect otherwise. For example, fluores-
Fig. 1. Cigarette -pack flasher.
cent lamps, dyes, inks, and even popular laundry detergents, take
on a whole new appearance under the sole scrutiny of a black light.
Table 1. Parts Listfor Cigarette -Pack Flasher.
Any object with any degree of characteristic fluorescence will take
on a weird coloration and actually glow in the dark. Certain rocks
Item No.
Description and minerals will also emit strange light colorations when you put
CI , C2, C3 0.47-µF capacitors. them near your black -light projector.
M1, M2, M3 NE -2 bulbs.
M4, M5 M6,
The circuit is uniquely simple and straightforward. The parts
M7 221/2-VDC batteries. are available through several commercial outlets, and no inter-
R1 mediary transformer or the like is required. See Fig. 2 and Table 2.
4.3-megohm resistor.
R2 3.6-megohm resistor.
R3
Curious experimenters might be interested to know the fact
3.0-megohm resistor.
that ultraviolet radiation falls below X-rays and just above visible
light on the electromagnetic spectrum.
12 13
OPENING
ARGON BULB
TOGGLE SWITCH
M3 3
EDISON SOCKET
14 15
Q 4 -Q
Fig. 3. Unusual musical effects device.
Tilter Box Oscillator
Table 3. Parts List for Unusual Musical Effects Device. Here is a gadget you cannot buy anywhere, yet it serves a useful
and entertaining purpose: that of keeping you awake when driving,
Item No. working, or whatever. Best of all, the curious will never know
Description
CI more than the fact that you have a common hearing -aid type
250 -AF, 15-w VDC electrolytic capadtor.
MI earpiece in your ear.
3-VDC battery.
M2
Guitar or other contact -type microphone. The idea is quite simple. Taped to the rear of the earpiece is a
M3, M4, M5
Motor -driven music box movements.
RI
500 -ohm, 3 -watt potentiometer.
subminiature mercury switch, positioned in such a way as to not
R2 make contact when worn normally. The minute, though, that you
110 -ohm resistor.
SI , S2, S3 Spst switches. begin to slump over from weariness, beep! This awakens you and
Three metal contact clips.
you resume a normal driving position, at which time the tone blast
One microphone connector.
Wooden box or minibox. ceases.
You can build the beep box into any handy plastic container-
the kind that small machine screws come in is ideal for this
purpose. For the transformer, you can use a Lafayette 99 H 6126 or
similar type. The battery can be a penlite cell or flashlight battery,
depending upon what size of container you are using.
Incidentally, wire the switch and earphone exactly as shown.
This will allow you to use the normal flexible earpiece cabling that
comes with most transistor -radio and hearing -aid phones, an aid
when you are wearing the tilter. Stiffer wire, of course, will work,
but will prove annoying after a while. See Fig. 4 and Table 4.
16
17
04 ELECTRICAL
HEAT -REDUCING
TAPE
M2 MERCURY SWITCH
M3 MINIATURE
EARPHONE Q1
M1
2N105
11/2VDC
T1
1) 5 ICQ
1111 Radio -Band Metronome
Fig. 4. Tilter box oscillator.
Here is a project guaranteed to delight builders, who have various
Table 4. Parts List far Tilter Box Oscillator. ideas on what they want from it. Basically, the radio metronome is
a tiny transistor transmitter which, instead of sending audio or
Item No. Description modulation to a remote receiver, sends loud "tick-tock" sounds.
M1 11/2-VDC cell. This device costs much less to build than a commercial
M2 One subminiature mercury switch. music -store -variety metronome you could buy. Also, you can vary
M3 One miniature transistor -radio earphone.
2K -3K impedance.
the frequency of the "tick-tocks." Another possible use is as a
01 2N105 transistor. device to help get you to sleep.
Ti Transistor transformer. (Lafayette 99 H It can be built into any kind of housing which you select to use,
6126 or equivalent.) and merely placed in close proximity to your AM table radio. Pick
One strip of heat -reducing or other elec-
trical -type tape to secure earpiece to
out a clear spot on the dial (someplace between two local stations, a
switch. spot not occupied) and simply adjust Ll until you hear your
radio -band metronome's signal. Once the frequency has been set,
adjust potentiometer R1 for the frequency of "tick-tocks" you
desire.
Should more distance be desired, run a short length of antenna
wire from the junction of Q1 -C1 -L1 indicated by the arrow in Fig. 5.
You may have to readjust Ll after doing this, but you will have a
much stronger signal. Also, see Table 5.
18
19
6 -Q
Fig. 5. Radio -band metronome.
Winking Night Light
Table 5. Parts List f or Radio -Band Metronome.
You can make a useful night light for the baby's room for the cost of
Item No. Description
a single .0047 -AF capacitor, and NE -2 neon bulb, an 11-meg
Cl resistor and a pair of 45-VDC batteries. If you can come up with
25µF, 15-w VDC electrolytic capacitor.
C2 .0022-uF capacitor. another way of supplying 90 VDC, you can make this device for
L1 700 turns No. 25 enameled wire wound practically nothing.
evenly on'/4-inch iron slug 11/2 inches The interesting thing about this device is that it will virtually
long. Tapped at 500 turns (this winding
group is soldered across C2). run forever. The NE -2 bulb consumes so little electrical current
M1 41/2-VDC battery. that between "flashes" the batteries tend to recharge themselves.
Q1 2N228 transistor.
R1
One such device constructed by the authors over two years ago is
2-megohm potentiometer.
R2 7.5K resistor. still flashing today, although the flash rate has dropped somewhat.
Si Spst switch. To compensate for this without replacing the batteries merely
change the RC circuit by altering the value of Rl. See Fig. 6 and
Table 6.
You can build this device into just about any container you
wish, although we remind you that anything in a youngster's room
is apt to take quite a beating. For this reason, it is suggested you
buy a toy and modify it for your own purposes; the selection of the
toy will pretty much depend on how large your batteries are and
how destructive your youngster is. At any event, once con-
structed, the night light should be sealed shut (a bit of heat does
wonders with plastic).
20
21
R1
'WV
11 meg M3
M2
TO047
90VDC
22 23
8 -Q
Fig. 7. Electronic chirper.
24
25
V1 V2
927 6BM5 M2
10µF
17 6 K1
2 3
2
22 3 4
R1 R3
MEG
T1 _o
51011
R2 5K
M1
si
.c/go-- 120V 9
TARGET -TUBE CIRCUIT
26
27
10 -V
Toy Telephone Amplifier
The only real problem with the working -type toy telephones
normally found in toyshops and department stores is that the
volume is much too low. Build this simple modification, however,
and you will have plenty of volume.
Follow closely the "original" and "additional" sections in Fig.
10. Compare the wiring and parts placement in the "original"
telephone with your own toy telephone circuitry. Mark clearly in
the book the proper color codes to coincide with your own system,
so that you can identify the wires. (Mark these wire colors on both
Fig. 9. Electronic fish lure. "original" and "additional" diagrams.) Also note any possible
differences between this circuit and your own. Once this has been
Table 9. Parts List for Electronic Fish Lure.
established, you are ready to proceed. See Table 10.
Item No. Next, solder the 2N331 transistor, Q1, and resistor R1 in
Description
place, taping the joints and other areas of exposed lead lengths so
C1, C2 2-µF, 150-w VDC electrolytic capacitors.
MI 90-VDC battery.
as to prevent any shorting. If your toy telephone is plastic, take
M2 11/2-VDC cell. precaution with the soldering -iron heat so that you do not melt
M3 11/2- volt high -frequency buzzer. anything! Make certain you use the proper battery polarity; if you
M4,M5 NE -2 bulbs.
R 1, R3
reverse it, you will ruin the transistor.
20-megohm resistors.
R2 7.5-megohm resistor.
R4 16-megohm resistor.
S1 (A,B) Dpst switch.
One peanut -butter jar.
28
29
M KE
TO
OTHER
PHONE
S2
Si
30 31
SALT -WATER
MOIST PAPER
SILVER
HALF -DOLLAR
M2
MOIST
PAPER
2070n
t HEADSET 0BATTERY
M4
M3
MI
0 CIRCUIT
Fig. 11. Coin battery.
:? 1 2 -Q
Table 11. Parts List for Coin Battery.
Item No.
Description
Electronic Metal Locator
M1 Half -dollar coin.
M2, M3
This project requires a few more parts than most projects in this
Test jacks.
M4
Code practice key.
book, but what you will wind up with is an amazingly effective
Q1 GE -2 transistor. metal locator you can use for finding wall studs, underground
Ti Transistor driver transformer: 20K primary, pipelines, and even buried treasure. Best of all, if you have a
2K secondary. (Argonne AR -103 or well -stocked spare -parts bin you can build it for little more than the
equiv.)
price of the metal box that houses the circuitry. This is inexpen-
sive, because unlike most metal locators, this one has a standard
table -radio antenna coil backplate for the critical metal -locating
sensor. Therefore, the major part of your total outlay for parts is
nothing more than a quick look into the parts bin. You will use the
entire backplate, feeding the antenna coil wires through an empty
paper -towel tube to the locator box.
To achieve the desired degree of sensitivity, you must "edge"
the antenna coil with a strip of normal household screening. See
Fig. 12 and Table 12. This is simple, since just about every time
you pull a loose wire on a window screen, you not only get the
ripped wire, but also a few inches of side "hairs" over the circular
coils in a more or less protective manner. Cut off the excess hair
length. You only want to cover the coils. Then scotch -tape the
whole arrangement so as to hold it in place. Do not make electrical
connection an any point. The screen rib and hairs should not make
connection in any electrical way with the antenna coil or the locator
circuit.
Once the primary circuit has been installed in the box and the
tube -antenna -coil unit mounted as shown, it is time to test your
32
33
locator. After tuning S1 on, increase the R5 setting to maximum Table 12. Parts Listf or Electronic Metal Locator.
Si MI
--ceo--1111
1.
15VDC
RIB OF HOUSEHOLD WINDOW SCREEN CLOSE-UP OF SCREEN RIB. SHOWING
USED AS SHIELD FOR ANTENNA HOW IT IS USED TO 'HOUSE" ANTENNA COIL
L2 HAIRS"
STANDARD AM
LOOP ANTENNA
TO DETECTOR RIB
SENSITIVITY
(----'k.,........\ TUNE
COMPLETED LOCATOR
co CONSTRUCTION DETAILS
Fig. 12. Electronic metal locator.
34 35
A) 13 -(Q1
Perpetual Beeper
and Meter Deflector
Here is a truly amazing gadget you can put
together for very little
cash outlay, and which will practically run forever. Best of all, it is
portable and can be arranged interestingly on a display board for Fig. 13. Perpetual beeper and meter deflector.
demonstration purposes.
An inexpensive 2N105 junction transistor is used, and, once Table 13. Parts Listfor Perpetual Beeper and Meter Deflector.
36
37
-Q 14 -Q
FM Wireless Transmitter
Here is a project that should not be constructed by those with no
patience for electronics building. While it basically uses parts that
can be obtained from any nearby radio -TV store (you can strip a
non -working radio or TV set for parts), it is a bit more of a project to
attempt and consequently presents more room for error than the
others in this book. For this reason building this project takes a
great deal of patience. The payoff is a sensationally powerful FM
transmitter that will allow you to plunk a hefty signal down
anywhere on the 88 -108 -MHz band with "broadcast" quality audio.
Additionally, many features are included that can either be utilized,
or simply left off your model, depending on how fancy you want
your wireless transmitter to be.
Typical of these additions is the VU meter, shown as Ml in
Fig. 14. Should you wish not to include this, merely omit both Ml
and resistor R14 entirely. If you want to "monitor" your own audio,
you can hook up a pair of earphones between ground and the
junction of the shielded cable, C5, and R14, and insert a 5K
potentiometer across the monitor lines. In this fashion you can
determine how far to advance volume control R11 without
introducing audio distortion. By the same token, you can use a
1N38B germanium diode across your earphones to permit monitor-
ing "wireless" transmissions. In this way, you are receiving the
actual on -the -air signals from the transmitter by bringing the diode
(and coil, if you want to be thorough) close to the broadcasting
antenna. In many respects, this method of monitoring is prefera-
38
39
Table 14. Parts List for FM Wireless Transmitter. ble, since you are hearing what the listener is hearing after the
modulation has passed through the 6AQ8 oscillator.
Item No. By the way, the junction point of R23 and R24 should be the
Description
C1, Ca C4, only point feeding plate voltage to the tube. If, for example, you
C8.C10.
CI7.C18 take your B+ from the cathode of the 6BX4 (pin 7), the voltage
.022-µF capacitors
C3. C6 .047-µF capacitors. would cause your transmitter to possibly violate Part 15 of the FCC
C5
C7
3.5-µF, 75-wVDC electrolytic capacitor Rules and Regulations due to the fact that it would be generating
1500-pF capacitor.
C9 50-pF capaotor
too much RF power output. For the same reason, the antenna
C11
C12
5-pF capacitor should be short. If the plate power increases, or the antenna is
15-pF variable capacitor. longer than just a few feet, your signals will be heard all over town
C13 1 10-pF capacitor.
C14.C15 510-pF capacitors. and the FCC will be looking for you.
C16 10-pF capacitor.
Cl 9 (A, 8. C)
The only two expensive components (if you do not have them
40,40/80-µF.450-wVDC electrolytic
capacitor. already) are the compactron, a triple -section tube manufactured by
C20, C21
L 1, L2, L3
.0022-µF capacitors. GE, and the power transformer.
3.3-mH rf chokes.
L4 512 turns of No. 16 enameled wire on The operation is simple. Just adjust C12 so that your signal
N -inch diameter form, spaced the appears on a blank space in the 88- 108 -MHz band. Stick to the coil
diameter of the wire.
L5 1 .5-mH rf choke.
values recommended, and you will have no trouble. Also, see
MI VU meter. Table 14.
M2
Microphone receptacle with locknut.
M3 AC wall plug with cable clamp.
M4
Coax receptacle.
R I . R7
110K resistors.
R2, R5, R10
1.3-megohm resistors.
R3. R8 1.1K resistors.
R4, R20 24K resistors.
R6 160K resistor_
R9 510K resistor.
RI 1
2-megohm potentiometer.
R12 11K resistor.
R13 680 -ohm resistor.
R14 5.1K resistor.
R15, R25 51K resistors.
R16 6.8K resistor.
R17 1K resistor.
R18. R27 1- megohm resistors.
R19 510 -ohm resistor.
R21 20K, 10 -watt power resistor.
R22 500 -ohm potentiometer.
R23 1K, 1 -watt resistor.
R24 2.2K resistor.
R26 4.3K resistor.
Si Spst switch.
Ti
120:250 -VAC power transformer. (Stancor
PS -8416 or equivalent.)
V1 (A,B,C) 6C10 compactron tube.
V2 (A,B) 6A08 twin -triode tube.
V3 613X4 duociode.
One compactron tube socket.
One 7 -pin miniature tube socket.
One 9 -pin miniature tube socket.
40 41
-Q 15 -EQ Fia. 15. Neon -bulb wattmeter.
Here is a gadget that could easily be called the simplest, most C1 .22-µF, 450-w VDC capacitor.
M1, M2 Test jacks.
inexpensive wattmeter in the world. Instead of complex circuitry M3, M4, M5,
filled with Nixie tubes and semiconductors, it relies entirely on M6, M7 NE -2A neon bulbs.
neon bulbs to do the work. When it is completed, you will be able to R1, R3, R5,
feed audio into the circuit (that would normally be fed to a speaker), R7, R9 1-m egohm potentiometers.
R2, R4, R6,
and the correct bulb will light signifying "3 watts" or the like. R8,R10 110K resistors.
Note that the presetting of a potentiometer determines when T1 Universal output transformer. (Lafayette
the neon bulb fires. The best way to do this is simply to feed audio 33 H 7503 or equiv.)
X1 100-mA, 400-PIV silicon diode. (Lafayette
into the circuit of a known wattage level. This will mean, of course, 19H 5001 or equiv.)
that you will be running the amplifier in question wide open-full
volume. If you know, for example, that this amplifier puts out a
maximum of 4 watts, simply adjust the corresponding potentiome-
ter in such a way that the bulbjust lights with this input. Next, move
to another neon bulb and repeat this procedure with a higher -
wattage known source, for example a table radio with an 8 -watt
audio output.
If it is difficult for you to calibrate your instrument in this
manner, you can do it with a variable -wattage source. For purposes
of calibration, you can use a 12.6 VAC filament transformer with a
100 -ohm potentiometer across it. The primary is connected to the
line and a variable voltage may be tapped off the potentiometer.
This voltage may be applied to the amplifier terminals according to
E= vn, where Z is the amplifier output impedance and P is the
wattage to be fed into the wattmeter for calibration purposes. For
example, for an output impedance of 4 ohms and a wattage of 4
watts, the voltage must be E = NAT 7( 4 = 4 volts. Be sure that the
wattage does not exceed the universal output transformer rating.
See Fig. 15 and Table 15.
42 43
-) 1 6 -Q
Flashlight Radio Transmitter
Fig. 16. Flashlight radio transmitter.
With two gadgets constructed identically from the circuit shown in
Fig. 16, you can simply aim one flashlight at the other and virtually
talk over the beam. In practice, of course, it's a lot easier to Tensor lamp with a hefty battery pack and a flashlight lens for
directivity. This provides a much more intense light, although it
construct your flashlight transmitters in two sections: (1) the main means more work. You will have to find some way of isolating the
unit with the magnifying lens mounted in a hole in the side of the
chassis or box (to admit magnified light so as to "trigger" a 2N280 power source from the prime supply voltage. If you want to do this,
feed the Tensor bulb 12 VDC direct, bypassing the AC transformer
transistor), and (2) the flashlight itself connected to the transmitter
in the base of the lamp. Rig up a series of 11/2-VDC batteries to
by a pair of wires, yet maintaining mobility for purposes of aiming arrive at the desired 12 volts, tapping off at 3 volts to feed the
the beam. Across the area between two houses, for example, you
circuit in the accompanying diagram. Under no circumstances feed
could operate your transmitter from an open upstairs window, more than 3 volts to the audio amplifier. Also, see Table 16.
aiming your flashlight so as to "hit" the magnifying lens (or
bullseye) of the sill -mounted transmitter in a friend's upstairs
Table 16. Parts Listf or Flashlight Radio Transmitter.
window. Particularly at night when you aren't troubled with
sunlight, you can communicate over considerable distances in this Item No. Description
fashion. It is important, however, that your flashlight beam hit the
C1 25-µF, 25-wVDC electrolytic capacitor.
target (magnifying lens) right on the nose. M1 Audio amplifier module. (Lafayette
The secret of this transmitter is the 2N280 garden-variety 99 G 9037.)
transistor referred to above. If you are careful, you can scrape the M2 9-VDC battery.
01 2N280 audio transistor with paint removed
paint off the outside of the transistor, exposing the internal parts of from glass case, exposing internal junction
the transistor to all onlookers. If you've done a clean job of it, you to act as ph ototransistor when light is pres-
now have an inexpensive light-sensitive sensor plus an amplifier, ent under magnified conditions.
R1, R4 11K resistors.
all rolled into one. You need only position the transistor under the R2 300K resistor.
magnifier so that the pin -point of light created by your friend's R3 75K resistor.
R5 -S2 20K potentiometer with spst switch.
flashlight is directed smack dab onto the 2N280. S1 functions as the
S1 (A,B) Dpdt switch.
transmit -receive switch, and S2 is part of potentiometer R5, acting SP1 8 -ohm transistor radio speaker. (Lafayette
as your off -on -volume control. 99 T 6036 or equiv.)
One flashlight.
Naturally, the greater the amount of light you beam out, the One magnifying glass.
farther you will be able to communicate. One trick is to rig up a
44 45
N MITENNA
MOUNTED AT N ANTENNA
CO tSFF u Tal*
NEP
-
CO22 HF
%I
Mt Et R4 T LS 1
120VEC
MCMC".4".AT iO N PNTERRATERMIR45.___I
fa -.0013 wF
Here is a versatile rooftop TV reception booster that will add a full TO LMOST3
.AACT,ON CHECK WITHCHIAMETER BASE
You can build it as is, or only include as much as you would OHEF,TIL.S4 rELGRAN
like. For example, if you break the circuit where the X's are IO OrnaTTUCTIONOF Wm/WORMERS
indicated, your booster will thrive entirely off its solar battery. If
you break it at the two Y's, the solar cell charges a 41/2 -volt battery Fig. 17. Solar TV reception booster.
pack during the day so the booster will work just as well at night as and
in direct sunlight. If you include all the circuit (taking into account upside down, you will notice an arrangement of leads as shown
the indoor AC supply shown), you can occasionally recharge the identified in Fig. 17.
41/2 -volt pack just in case you have had a protracted period of rain or Take care in constructing your coils that you duplicate exactly
overcast weather which prevented the solar cell from sending its those turns and techniques recommended in Table 17.
energy down to the reserve battery. Once complete, you can test out your booster by hooking it to
Construction is not complicated, but since you are dealing the TV set and placing a lit 60 -watt lamp bulb in rather close
with both vhf and uhf signals, you will have to keep all leads proximity to M5. As the lamp is turned on, you should get a
extremely short and direct. In fact, you would do best to cram the much -improved picture. Adjust the best reception on all channels
parts close together so as to cut down on the length of interconnect- by tuning IA and the coupling between LI and L2. Now mount at
ing wires. Looking at the schematic, you will note that Q1 must be the TV antenna, positioning M5 for best sunlight hits.
grounded; this is no problem; however, since the HEP-3 comes Hint: Leave the AC plug plugged in at all times. It will not
with four leads instead of the regular three. Turning the transistor draw power until you throw switch Si onto "charge."
47
46
Table 17. Parts List for Solar TV Reception Booster.
Item Mo.
Description
Cl
56-pF capacitor.
C2, C3, C6 .0022 -AF capacitors.
C4
1.5-pF capacitor.
C5
18-pF capacitor.
C7
150 -AF, 15-w VDC electrolytic capacitor.
C8, C9 .0022 -AF capacitors.
L1
71/2 turns No. 24 enameled wire,
evenly
wound on a 3/16 -inch -diameter form.
L2 3 turns No. 24 enameled wire evenly wound
on a 3/16 -inch -diameter form.
L3 17 turns No. 24 enameled wire
evenly wound
on a 3/16 -inch -diameter form.
L4
11'/x turns of No. 24 enameled wire
evenly
wound on Speer Type E f errite form.
L5, L6 10 turns No. 24 enameled wire evenly wound
MI on Speer Type E ferrite form.
M2, M3
M4
41/2 VDC, with three penlites of NiCd cells.
Binding posts.
AC wall plug with cable clamp.
c 18 -E;?
M5
41/2-VDC Solar pack. (International
01
Rectifier No. SP5G26C or equiv.)
H EP -3 transistor.
Free -Power AM Radio Receiver
RI 51K resistor.
R2 30K resistor. Strange as it may seem, this transistor broadcast -band radio
R3
R4
240 -ohm resistor. receiver "steals" power from one station to give to another! The
110 -ohm resistor. principle is basic: By tuning the battery -section antenna coil (L2) to
R5 750 -ohm resistor.
Si Spst switch. the strongest broadcast station on the band, diode X1 can rectify
T1, 72,13,14 Using Ferroxcu be K5050-06 ferrite cores. the rf and convert it into DC current. Naturally, the closer you are
insert 2 turns of special 300 -ohm minia- to a strong station, the more current the "radio battery" section of
ture twinlead in each form hole. Pull
tight, and connect leads where shown in
your radio receiver will be able to supply. Once you have found this
T5 diagram. spot, the DC current is passed on to power the transistor circuit
6.3 -VAC filament trnasformer. (Triad which acts as a genuine receiver, with the full tuning it affords. See
F -14X or equiv.)
Fig. 18 and Table 18.
The basic consideration is a good antenna and ground, the
latter preferably being made to a water pipe or solid external
ground composed of a pipe driven at least 4 feet into moist earth.
This procedure not only ensures maximum signal pickup for the
radio -battery portion of the circuit, but also provides best results
for the GE -2 receiver circuit.
Once completed, just tune the radio battery as explained in the
first paragraph and calibrate your receiver by adjusting LI so that
the bottom of the band occurs when Cl is fully meshed. If you have
a local broadcast station operating near 540 kHz, this simplifies
things tremendously. Once the calibration procedure is complete,
forget entirely about adjusting Ll and do all your listening by tuning
Cl.
48
49
MI ANT
M2
01
EXTERNAL CI GE -2
GROUND
TO EARPHONES
365p,
1 9 -Q
RADIO BATTERY
Item No.
Cl
M1
Description
.022-µF capacitor.
120-VDC battery.
21 -V
M2 NE -2 bulb.
SP1
Ti
Transistor radio speaker, 3.2 ohms.
Transistor radio speaker transformer.
Aquarium Heater Silencer
One clothes hanger.
Plastic speaker box. Plagued by reports of neighborhood TVI and BCI, one of the
Plastic box. authors noticed that the interference complaints persisted even
when he was not on the air. In one case, on return from a two-week
vacation the next-door neighbor insisted that the author had left a
transmitter running, because he continued to get interference,
particularly annoying to him on the AM broadcast band. This
problem sounded like a power -line problem, so the local power
company was called onto the scene.
Imagine the surprise to learn that the trouble emanated from
an aquarium heater in a tropical fish tank a block away! Apparently
the heater arced over just before it came on, and just after it went
off, in its normal thermostatic operation. This arcing, traveling
through the house wiring, found its way into the main street lines,
and worked its way into every home on the block.
Unfortunately the party with the cheap aquarium heater did
not want to invest in a nonarcing model. Hence, the circuit shown
in the accompanying diagram was devised. Even with brand-new
parts, it should not cost over $5.00, including the minibox housing.
Functionally, the silencer filters out "popping" noises by
grounding them before they reach the main power line. In
operation, you merely plug the silencer into the nearest AC outlet,
and plug the aquarium heater cord into the silencer socket.
54
55
;) 22-(Q
Electronic Tic-Tac-Toe
Fig. 21. Aquarium heater silencer.
Here is a dandy project that requires only a good supply of 6.3 volt
Table 21. Parts List f or Aquarium Heater Silencer.
bulbs, a filament transformer, assorted spst switches, an spst
switch, plywood board, and a supply of hook-up wire to build an
Item No.
Description
impressive automatic electric tic-tac-toe machine which will
C1. C2, C3, C.4 fascinate the youngsters and oldsters alike for many hours on rainy
.022-µF capacitors.
L1, L2 Solid windings of No. 16 enameled wire on days.
1 -inch diameter form. Fill with solid The secret of this game, which is built on the back of a sheet of
windings to a 5 -inch overall length.
M1 plywood which is painted with cross -hatch tic-tac-toe lines, is the
AC wall plug, with cap and cable clamp.
M2 AC socket. use of colored filament bulbs. The reason for the nine green bulbs
and nine red bulbs is so you can keep track of which move was made
by which player. Simply assign one player one color, and the other
player the other color. Incidentally, you do not have to go searching
for colored light bulbs; you can just as well drill "peep holes"
through the tic-tac-toe board and tape Kodachrome transparency
plates across the holes on the game side so that the light streaming
through will take on the hue of the transparent sheet. In any case,
you will have to arrive at a color arrangement in order to keep from
getting one player's moves confused with another's.
With the switches wired as shown in Fig. 22, each of the nine
switches corresponds to one of the tic-tac-toe boxes on the
crosshatch pattern. Whether you throw the switch right or left to
go on is determined by which light you want to become illuminated.
For example, the "red" player always switches right. The "green"
player switches left. It is impossible to make both bulbs in any
given box come on at one time.
When the game is complete and winner established, merely
return all switches to a center position and all the bulbs will go out.
Now you are ready for your second game. Also, see Table 22.
56
57
ff car. ED TICK TAU TOE
LINES ON CHASSIS N.
M3 kr. MIS
of. -*SS
c/.
0--
-) 23 -V
-V 00- -oS6 or o-
Fence Charger
M19
58 59
24-Q
Fig. 23. Fence charger. Receiver Signal Alarm
Check the battery condition from time to time, as well as Have you ever waited hours on end for a certain call to come across
outdoor connections. Rust and dirt can ruin the best electrical your CB set, afraid to leave the room for fear you would miss it?
joints if you don't inspect them periodically. See Fig. 23 and Table Well, this gadget will set off a bell or buzzer alarm whenever it
23. "hears" an encoded signal on the receiver. This is especially good
Suggestion: If your local laws do not prohibit it, this circuit is for ham radio operators belonging to a 24 -hour -per -day network on
great for a portable shocker for warding off attachers. Use 2 meters, and for monitoring emergency CB channels. As the call
flashlight cells and build it with a portable "shock rod" with two comes through the high-pitched "beep" tone, the buzzer "fires."
prongs, one for the "hot" lead and one for "ground." NOTE: In New Interestingly, a door -chime is particularly effective. The
York a young woman lost a legal case because she had employed a authors set one up next to the original front -door bell ringer and
shock rod as her defense when attacked by a night assailant. The wired it to the CB set (which was fixed -tuned to CB Channel 2, a
shock rod, while not illegal to possess, is illegal to use in local emergency frequency). It has a different tone altogether from
Manhattan. the regular doorbell, yet it is pleasing to hear and not at all
Table 23. Parts !Attar Fence Charger. bothersome. It takes its power from the original bell transformer in
the basement (24 VAC) and is switched on and off through the
Item No. Description receiver signal alarm box.
C1 500-µF, 10-W VDC electrolytic capacitor. NOTE: You do not have to disconnect your speaker; just wire
C2 2000-µF, 15-w VDC electrolytic capacitor. in the circuit in Fig. 24 across the two speaker cables and adjust R3
M1
M2, M3
6-VDC battery.
Test hacks. for the desired audio level required to "kick -in" the alarm circuit.
Q1 GE -3 transistor. Also, see Table 24.
Al 15K potentiometer.
R2 160 -ohm resistor.
S1 Spst switch
T1
6.3 -VAC filament transformer (Triad F -14X
X1 or equiv.)
1N540 diode.
60 61
Fig. 24. Receiver signal alarm.
62 63
I
I
TOP
- -Q 26 -V
MAGNET PLACED
VERY CLOSE
I
Electric Combination Lock
I
CYLINDRICAL TO BOX TOP
MAGNET
Here is a circuit, limited only by your imagination, that will
I
SLEEVE
I
..____
SETSCREW II guarantee secrecy and privacy, as well as baffle the most
.
determined would-be intruders. It is a complex electric locking
system which depends entirely on a straight -through electric
1
\\ MOTOR SHAFT
III
I circuit for it to function.
M3 It can be used "as is" for a number of applications. For
SPEED
+ ) example, you can simply feed the input to the household AC line
M1 R1 CONTROL
and the output to the 120 -VAC line going to your ham transmitter,
II
1V2VDC
S1
L
5052
alJ
1
CB rig, TV set, or the like. If the lock box is permanently installed
as part of the wiring between the AC outlet and appliance, radio, or
whatever, it will be impossible to get the unit to function without
1111
______
III In the circuit shown in Fig. 26, the switches are placed exactly
WOODEN BOX as shown on the face of a panel. This means that there will be two
control knobs (each of the switches used will "read out" to numbers
Fig. 25. Magic magnet box. 1-13 on your panel) in the top row, two in the next row, and the last
positioned on the bottom between the two above. It looks as if you
Table 25. Parts List f or Magic Magnet Box. want to start at the upper -left; actually it would take you about
three weeks of experimenting, starting from the bottom switch, to
Item No. Description unlock the mystery. In the illustrated circuit, the combination,
M1 11/2-VDC cell.
M2
reading from Si to S5, is 4-11-1-9-13. Unless all switches are
Cylindrical magnet. (Edmund Scientific No.
P-40,418 or equiv.) dialed in order to those numbers, nothing will happen.
M3 Battery -operated electric motor. (Edmund Additionally there is the hidden switch (S6) which must be
Scientific Co. No. 30,305 or equiv.) depressed after all the preceding has been performed in order for
R1 50 -ohm potentiometer.
S1 Spst switch.
the circuit to operate. It's best to hide this switch in a drilled -out
Wooden box. recess and paint it over so as to conceal it entirely. Only you will
know where it is. If you do recess it, it will take the eraser end of a
pencil to depress it, particularly if you use a tiny, subminiature
type.
If you have a laboratory, electronic workbench area, or other
room which you do not want open to intruders, buy a solenoid -
operated door latch through your local hardware store and replace
the conventional door lock with this mechanism. Some operate on
as little as 6 VDC, others on standard household current. The
electric combination lock can be installed on the door itself, with
the knobs and numbers projecting on the outside (facing away from
your room) of the door.
64 65
13
12 o 2 01
110 0 02
o104 5
30
0
03
04
09
05
08
070 06 27 -EQ
Echo Box
12 o
13
1 12 1301
02 02 Ever wish you had a professional echo chamber similar to those
110 110
03 030 used by disk jockeys? All you need is a tape recorder, an expensive
10
04 0 04 replacement tape head, a 2N417 transistor, and handful of
09 05 90 5
components. Construct the circuit carefully, and you will sound
08
07
06 80 06 like you are in Grand Canyon. Figure 27 (C) shows how the echo
box is hooked into your audio or transmitting system; the pictorial
6
13 (B) shows how the echo effect is obtained through installation of a
12 0 01
02 new recording head. Also, see Table 27.
11
0 03 If you want to be able to vary the spacing of the echoes, you
10
0
will want to be able to "slide" the new tape head back and forth to
4
90
obtain this feature. Naturally, the farther away you place the new
M1 05
08 07 06 M3 tape head from the original head, the greater this spacing will
TO OUTPUT TO become. Adjust the "dominance" through potentiometer R5, which
POWER SOLENOID -OPERATED
permits your allowing the echo to be the primary audio source, or
SOURCE *
M2
LATCH
O the original voice to be the primary audio, whichever you prefer.
NOTE: Although the schematic shows the output going "to volume
control on amp," the output can be coupled to the input of most any
Fig. 26. Electric combination lock. amplifier. If you have a stereo amplifier, you can run the main
recorder output to channel 1, and the echo box output to channel 2.
Incidentally, in the five -switch circuit there are 371,293 The effect is interesting.
possible combinations. If you use a lower number of switches, here If you have no additional amplification requirement, then wire
are the numbers of combinations: 2 switches, 169 combinations; 3 into the "hot" lead of the volume control on the recorder itself. This
switches, 2197 combinations; and 4 switches, 28,561 combina- permits your playing back any recording you make, inserting the
tions. echo effect by simply adjusting the dominance control.
Table 26. Parts Listfor Electric Combination Lock. If you want to add the echo effect to your CB or ham
transmitter, feed both recorder and echo box outputs together, so
Item No. that you wind up with just one "hot" and one "ground" lead.
Description
M1, M2, M3, Preferably this should be accomplished through the use of common
M4 Test Jacks garden-variety microphone cabling. Just before you plug this single
S1. S2, S3. S4,
S5 mike cable into your mike connector on the CB rig, insert a 15 -SF
13 -position TV channel switches (rotary).
S6
Push-button switch, normally open.
capacitor in the "hot" lead. This capacitor serves to isolate the
output of the recorder/echo box from the modulator to avoid
66 67
TO
VOLUME
CONTROL
ON AMP
-Q 28 -0
SI
Pool Splash Alarm
MI
I. I K C"-1.11-- If you are the proud owner of a backyard swimming pool, chances
9VDC "717
are that you are also the owner of one long continuous headache.
OHEAD PLACEMENT
The problem with these pools is keeping the neighbor children
MAIN SPEAKER
ACTUAL RECORDING
RECORDER
RECORDER - OR
I
away when you are not around, plus animals and small children who
HEAD TAPE PASSES ACROSS
NEW HEAD
AMP
I
TRANSMITTER might wander near the pool at night, creating the danger of
drowning in an unsupervised swimming pool. While the pool splash
IECHO BOX
alarm described here is no panacea, it does help, particularly at
TAPE
night when the household is asleep. Its drawback is that it responds
NEW
TO ECHO BOX SLIDING
only to a sudden wetness resulting from a splash, and this is
HEAD something to think about before you go advertising your new
invention all about the neighborhood. You will be somewhat
Fig. 27. Echo box. aggravated when you find out how many stones get thrown in your
pool at night by curious youngsters eager to see your lights come
damaging the transmitter. If you do feed it into the modulator, on and the buzzer blare.
leave the modulation gain control exactly where it was originally So do not tell everyone what you are doing. You can simply
set for straight mike operation, and do your level -adjusting with the describe the probe wires as a gadget that has something to do with
volume control on the recorder and the dominance potentiometer the water level and purifying mechanisms and leave it at that.
(R5). You will not need much output, since the audio amplifier in The main splash alarm circuitry should be in a box somewhere
the modulator does most of the work. Keep levels of both controls in the house or garage, with insulated cabling to the probes either
down, monitoring output through a crystal detector or grid -dip buried underground or held down with clamps to prevent someone
meter with earphones to avoid distortion. from tripping on them.
Table 27. Parts List f or Echo Box. The probes can be separated by any length at all. One must be
under water at all times, while the other has to be adjusted ever so
Item No. Description carefully to detect a sudden rise in water level such as would occur
Cl, C2, C3, C5
by someone falling (or slipping) into the pool. In permanent
15-ALF, 50-wVDC electrolytic capacitors. installations, it is advisable to use a strip of conductive paint on the
C4 100-µF, 50-w VDC electrolytic capacitor.
M1 9-VDC battery. side of the pool just V2 inch above the water line, although this
01 2N4 1 7 transistor. requires that you maintain a predetermined water level in the pool
R1 51K resistor.
R2 11 K resistor. at all times. For other installations a stiff wire probe (such as No.
R3, R6 1.1K resistors. 10 or No. 12 bare wire) can extend down over the rim of the pool to
R4 5.1K resistor.
R5
a point just above the water surface. If you design it correctly, you
10K potentiometer with spst switch.
Si Spst switch on R5. will be able to adjust the height of the probe from time to time. See
Tape recording head. (Lafayette Radio Fig. 28 and Table 28.
99R 6194 or equiv.) The authors suggest that your buzzer be placed in a position
where it can be heard in all occupied sections of the house. If this is
68
69
Fig. 28. Pool splash alarm.
70 71
M2 ANTENNA
0
47,? 30 -EQ'
01
2N105
C1
M3
TO
Automatic Animal Flasher
365 pF MIKE
L1 C3 R2
Are you a photographer who likes to get good out-of-doors pictures
C2
47
51K of wild animals in their natural habitat? Ordinarily, such photos are
beyond the abilities of the average camera enthusiast, but with the
RI flasher device described here, you will be turning out amazing
91ft pictures on a par with the professionals.
The key to good night shots is catching the animal totally
unaware. Aside from sitting in the woods all night freezing as you
avDC= wait for raccoons and deer who know better, you can simply rig
R3
VVV your camera up on a pole, wire in your flasher system, and plant the
110K
"bait" (which can be anything you think will attract wildlife, such as
bread crumbs, jelly, etc). The automatic flasher will "sense" any
Fig. 29. Wireless mike animal activity and immediately get off a shot before the creature
knows what hit him.
Table 29. Parts List f or Wireless Mike.
As shown in Fig. 30, this circuit has been set only to activate a
Item No. flashbulb mounted in such a way as to throw maximum illumination
Description
Cl
upon the animal sniffing around the food supply. This means you'll
365-pF variable capacitor. either have to wire in the shutter mechanism to the circuit, or
C2 .0068-0.4F capacitor.
C3 47-pF capacitor. follow the conventional method of opening the shutter to a setting
L1
Tapped loopstick. (Lafayette 32 H 4108 or or exposure correct for the flash being furnished. The lens will
equiv.)
M1 9-VDC battery.
have to stay open until you retrieve your camera or reset the
M2 Binding post. system. This is not really a problem, however, since the flashbulb
M3
01
Microphone receptacle. will fire and then go out, leaving the camera in near -total darkness.
2N105 transistor.
RI 91 -ohm resistor.
A double -exposure is impossible unless the camera is left out all
R2 51K resistor. night until the sun comes up.
R3 110K resistor. As indicated in Fig. 30, three sensing elements are used,
Si Spst switch.
although you can elect to use any one, or two, or combination to
achieve maximum animal sensitivity. The microphone is by far the
most dependable of them all, although it might not respond to every
presence, particularly of certain birds. In that case, the photocell
can be employed by directing a stream of light at the cell. If a bird or
other animal interrupts that light stream by casting a shadow on the
photocell, the flashbulb will fire. The moisture -sensitive sensor
plate is a conventional type available through most large elec-
tronics and scientific supply companies. Be sure, however, you
buy the most sensitive plate available, not the kind designed to
sense only large drops of rain. An animal's feet are normally much
72 73
31 -EQs
Long -Distance
Fig. 30. Automatic animal flasher. Light -Ciphering Machine
more damp than human skin; hence when the animal steps on the Recall the flashlight radio transmitter described in Project 16? This
plate enough of an electrical connection will be made to trigger the light -ciphering system is much less complicated, is somewhat
flasher circuit. WARNING: Do not use the sensor in extremely more dependable over a greater distance, and is less expensive if
damp weather. you are buying all new parts. Communications are carried out by
The sensitivity you want is determined by where you set R3. tone beeps over a Sonalert generator, a great gadget for devices
Maximum sensitivity may be too great; it might respond, for which operate on small voltages. You can use International Morse
example, to the sound of birds fluttering in overhead trees. Try to Code (available in ARRL publications, as well as Boy Scout
imitate the intensity of the sound you think the animal will make, manuals and other sources), or you can simply make up your own
and use a homebrew cardboard tube or parabola -type cone over the
beeping -code system, using certain arrangements of long beeps
mike to direct its pickup directly at the baited spot. You'll lose a and short beeps to represent secret prearranged codewords.
few flashbulbs in setting it up, but your photos will be prizewin- Unlike the other project, no magnifying lens is required in this
ners.
system. Additionally, you can either use the push button on the
Table 30. Parts List' or Automatic Animal Flasher. primary flashlight on -off switch as your signalling device (taking
care that you do not move your light beam off target), or you can
Item No. Description wire it for outboard operation as shown in Fig. 31. In any case, the
C1 500-µF, 25-wVDC electrolytic capacitor
M1
signal light is not part of the base code -ciphering circuit and
9-VOC battery.
M2 Standard flashbulb. consequently separate battery supplies are provided. For best
M3. M4 Single -prong test plugs. results, you will probably want to separate the two major
M5 2 -conductor shielded microphone plug.
M6, M7 Test tacks.
items-the photocell "target" and the flashlight signaller-
M8 2 -conductor shielded microphone receptacle. somewhat in the final physical layout of your system.
01 TI -415 transistor. The only thing you have to worry about is shielding the
02 TI -419 transistor. photocell from unwanted sources of stray light. If you build this as a
R 1, R2 51 -ohm resistors.
R3 2-megohm potentiometer with spst switch. permanent communications system between, for example, your
R4 1.6K resistor. house and your friend's down the street, you can mount both the
S1 Spst switch on R3. flashlight and photocell remotely on the roof or on a ledge placing
S2 Spst switch.
X1 2N3228 SCR. them in direct line -of -sight with each other and preaiming both
systems. Once the sensor and flashlight have been secured in
74 75
Fig. 31. Long-distance light -ciphering machine.
76
LINES FROM CONTROL UNIT
78 79
Fig. 33. Matchbox oscillator.
Item No.
C1
Description
FM Music Receiver
.047 -AF capacitor.
M1
6-VDC hearing -aid subminiature battery
supply.
Here is a clever one -transistor FM receiver which is well worth
M2, M3 Single -prong test plugs. your time and effort. It will do an adequate job in most metropolitan
M4. M5
01
Test jacks.
GE -5 transistor.
areas, and it exhibits an extraordinary ability to pull in the weak
02 2N105 transistor. stations if you live out in the country. If you start from scratch, with
R1 62K resistor. all -new components, this project will not cost more than a few
R2 75K potentiometer or variable resistor.
S1 dollars.
Push-button switch.
SP 1
Transistor radio8-ohm speaker. (Lafayette
The heart of the receiver is an efficient superregenerative
99 T 6032 or equiv.) design and a "gimmick" capacitor linked between the emitter and
collector of Q1. This capacitor is really a homebrew type you can
make from two 1 -1/16 -inch lengths of No. 16 insulated hookup
wire. Just twist them together for best results. Anywhere from 1/2
to 4 turns should do the trick.
Adjust the potentiometer until a "rushing" sound is heard in
the earphones-right past the threshold point-and you are all set.
Tuning is accomplished with C2. See Fig. 34 and Table 34.
80 81
ci
(GIMMICK)
01 MAIN ANTENNA
HEP-2
3 C2
'TUNING
30 pF
M1
LI
15µF
C3
35 -C
REGEN
---1 C4
2 5 meg "i M3 M5
12 pF
TO 2K -3K
Transistor Tickler
EARPHONES
Are you one of those types who just cannot pass up an opportunity
OFF -ON M2
for a little fun? The mysterious tickler box is just the project for
Si *I
9VOC
LS
Ma MS
you. You merely hand it to someone and stand back to watch the
action. Our bet is he will drop it like a hot potato, unless he is
unusually accustomed to receive jolts of electricity in the
Fig. 34. FM music receiver. thousands -of -volts range!
Actually, this circuit is nearly harmless, since the 11/2 -volt
Tab e 34. Parts List for FM Music Receiver. flashlight battery can hardly supply enough current to give more
than the feeling of a slight, but annoying, tickle to whoever comes
Item No.
Description in contact with the tickler/sensor. Yet it's great for parties,
Cl "Gimmick" capacitors 1/2 to 4 turns No. 16 particularly when you tell your victim that he's just received a mild
insulated hookup wire. (See text.) 20,000 -volt shock!
C2 2-30-pF variable capacitor. The heart of the circuit is the filament transformer, which
C3 .15-µF capacitor.
C4 does most of the dirty work. For best effect, the tickler should be
12-pF capacitor.
LI 83/4 turns of No. 20 wire, 1/4 -inch constructed in a cardboard or plastic box with the sensing/tickling
diameter, 3/4 inch long. element wrapped around the outside of the box. One way to do this
L2 23/4 -turn link of No. 20 wire, spaced
1/4 inch from LI.
is simply to wind bare coil wire around the box in such a way as to
L3, L4. L5 7-µH coils. (OhmiteZ-50 or equiv.) insure that the coils do not come in touch with one another, yet will
MI
M2
Binding post. be hard to hold without "shorting" them out with the skin of the
9-VDC battery.
M3, M4 Test jacks. victim's hand.
M5, M6 Single -prong test plugs. A much simpler way to build this gadget is merely to fasten
01 HEP-2 transistor. two metal plates to the box, one to cover the bottom of the box, and
RI
Si
2.6-megohm potentiometer.
Spst switch. one for the top. The top plate can also extend over the sides, so
long as it does not electrically touch the bottom plate. These plates
can be made out of any flexible metal sheeting (even aluminum foil)
and fastened to the box by machine screws or glue. The two wires
from the output of the filament transformer are connected, on each,
to the plates. In this manner it is virtually impossible for someone
not to receive a tickle when he picks up the box.
Incidentally, this upper -and -bottom -plate concept works well
in actual use. If you build it for a youngster, for example, you can
82
01
Ti
2N297 TICKLER. SENSOR
mi $i
Al
iv2voc
2K
CI
+1
I 50ALF
0 CIRCUIT
METAL TOP CASING
FLEXIBLE TICKLER SLEEVE WIRED TO TRANSFORMER
TO ENCASE BOX
84 85
GAN
INPUT "I
GRN
RED
PREACILIST
BLIP
TEL
TEL
IS2
ONCIFF
-Q 37 -V
III'
' 9VDC : D3
CCNCE;41. ED
:
Here is a dandy little gadget that will enable the skilled to play
113 music without even touching the "organ"! Working entirely on a
5
light basis, the shadow of your hands moving over the two
photocells produces weird musical effects, particularly if you space
CHASCPANOEFK3NIULT BOY the two photocells in such a way that permits your using both
hands, one photocell for each.
Fig. 36. Chaos -pandemonium box. The heart of the gypsy light organ is the unijunction transistor
Table 36. Parts List f or Chaos -Pandemonium Box.
oscillator module, available from moist major electronic parts
suppliers. In conjunction with the two photocells shadows vary the
Item No. Description amount of voltage reaching the module; hence the variable tones
M1 Three -transistor amplifier. (Lafayette are produced.
99 C 9039 or equiv.) You can feed the audio output into a standard hi -ft audio
M2 9-VDC battery.
M3 Dual -flasher module. (Lafayette 19 C 0106
amplifier, or wire in a small transistor amplifier.
or equiv.) Anyone who has a good musical ear should be able to learn
M4, M5 No. 47 bulbs. many song selections and numbers on this light organ. See Fig. 37
M6 Siren module. (Lafayette 19 C 0105 or
and Table 37.
equiv.)
R1, R2 1-megoh m potentiometers.
S1 Normally -closed push button.
S2 Delayed -action switch. (Lafayette
34 R 3805 or equiv.)
S3 Subminiature spst switch.
SP1 Transistor radio speaker. (Lafayette
99 T 6032 or equiv.)
86 87
A) 38 -(Qi
Fig. 37. Gypsy light organ
Hi-Fi Color Lights
Table 37. Parts List f or Gypsy Light Organ.
Are you interested in adding unusual visual effects to your hi-fi,
Item No. Description
stereo, or FM radio radio system? This is possible with the gadget
Cl outlined in the accompanying diagram. By plugging in a lamp (using
500-µF, 25-wMDC electrolytic capacitor.
C2 2-j.i.F electrolytic capacitor. colored light bulbs, if you like, up to a total of 200 watts), the
M1, M2 Photocells. (GE Type X6 or equiv.). brightness of the light is actually controlled by the audio signal.
M3 Microphone receptacle with locknut.
M4 AC wall plug, cap. and cable clamp.
Thus; as the lilting strings begin, the colored lamp is just barely
M5 Unijunction transistor oscillator module. glowing; when the bass drum is hit and the brass begins blaring, the
(Midland Standard Type 5100-4A.) corresponding bulb emits a more intense light. The dancing color
RI 11K resistor.
R2
lights cannot be fooled. If a sharp difference in sound occurs, the
1.1K resistor.
R3 510K resistor. same will be noted visually the instant it occurs.
Si Spst switch. Construction is not difficult and the unit can be wired into a
Ti Isolation transformer, 120:120 volts.
(Allied 54 C 1426 or equiv.)
very small container, complete with RCA phono plug for audio
input and a standard AC socket for 120 VAC output. Take care to
avoid shorts; note that at no time is any portion of the circuit
grounded to the chassis. See Fig. 38 and Table 38.
Testing can be accomplished with a 30- or 35 -watt bulb
plugged into the AC output socket. With no audio present, a slight
glowing should be present. A low-level audio signal should drive
the bulb to nearly full brilliance.
For best effect, you'll probably want this glowing to disappear
when no audio is on the line. You can vary the "firing point" of the
light bulbs by substituting a 100K potentiometer for R2; generally,
the more resistance you insert, the less the resultant glow.
Although the circuit will drive a 200 -watt load, you may find
rover-all operation cooler if it is kept down to, say, 125 watts.
89
A) 39 -Q
Fig. 38. Hi-fi color lights. Electronic Rainmaker
Table 38. Parts List for Hi-Fi Color Lights. Ever find yourself wishing it were a rainy day just so you would be
able to get to sleep easier? The circuit in the accompanying
Item No. Description illustration will duplicate exactly the sound of a soft rainfall. It has
Cl .022-µF capacitor. been "lifted" from a device used by sound -effects men for use in
C2 .047-µF capacitor.
C3
taping radio shows where a rain sound must be injected. Reworked
.068-µF capacitor.
C4 .0022-µF capacitor. for personal application, the gadget is a two -tube table -model
M1 Colored household (120 -VAC) bulb, to adapter for use with a tube -type AM or FM radio. The only use
150 watts.
M2 Microphone receptacle with locknut.
which the radio serves, actually, is a source for the required 150
M3 AC wall plug, cap, and cable clamp. and 250 VDC required to power the electronic rainmaker. The
Ma AC socket. prime rainmaker unit contains its own speaker, and can be adjusted
M5 Full -wave bridge rectifier module.
(Erico FWB 3006A or equiv.)
both for desired volume and for the kind of a rain you'd like to
R1 36K resistor. duplicate. With the circuit here, you can simulate anything from a
R2 43K resistor. light spring shower to a crashing, fierce summer thunderstorm.
R3 220K resistor.
T1 410K -ohm output transformer. Heart of the unit is a Solitron SD -1W white noise generator,
(Thordarson TR-203 or equiv.) although other types will work as well. The noise is injected as
X1, X2, X4 1N4003 silicon diodes. desired through R12, the "rain control." Note that the circuit
X3 TI -42 trigger diode.
X5 2N3528 SCR. contains extensive capacitive padding which accomplishes the
softness required for true duplication of the genuine weather
condition. See Fig. 39 and Table 39.
90 91
Table 39. Parts Listf or Electronic Rainmaker.
LL
ms>
--H... u..
-yv\--E 3 ?"
92 93
C3
3 M4
300µF 300µF
4^r GE -1
GE -1
Q2
C)1
R5
R4 200 20,3W M1
+ I
R6 R7 10K 3VDC
10K
S3A S3B
-Q 40 -Q
4
4
3 o 10K
23
_o pob R3
10
94
95
1
97
96
Fig. 42. Match -needing electric lamp.
42 -EQ,
Table 42. Parts List for Match -Needing Electric Lamp.
Item No.
Match -Needing Electric Lamp M1
Description
3- VDC battery.
M2 1.25 -volt bulb. (GE -123 or. equiv.)
For more fun with electric lamps, build this novel gadget and watch M3 Photocell. (RCA 7163 or equiv.)
the reaction you will get. After throwing the switch "on," there is 01 2N1177 transistor.
R1 50K potentiometer.
virtually no way to get the bulb to light except by lighting a match Si Spst switch.
and bringing it close to the concealed photocell, M3. Once the
photocell senses the light, it causes bulb M2 to light, and the light
from this bulb landing on the photocell keeps the lamp on until you
open switch Si.
Properly built into a small standard desk lamp fixture or table
lamp, you will be able to mystify friends every time you light up. Of
course you will have to rewire the lamp to house the circuit, and rig
it with a 6 or 1.25 -volt bulb instead of 120 -VAC type, but you'll still
get a lot of light and have the added feature of automatic response to
a lighted match.
The secret of doing this correctly is to locate the photocell in
such a position that it will not pick up stray light from other
sources, yet will respond to both the light from the bulb and your
match. Trail and error works best in this case, as positioning will
vary from one installation to another. See Fig. 42 and Table 42.
98 99
-2,? 43 -Q
Junior -Size Tesla Coil
Ever have an urge to man one of those fantastic machines that Boris
Karloff is always fooling with in old Frankenstein movies? Well,
probably 90 percent of these films make use of hissing, zapping, Fig. 43. Junior -size Tesla coil.
Tesla coils for visual effects. And you can build a scaled -down Table43. Parts List for Junior -Size Testa Coil.
version of these monstrosities and still wind up with a wild device
capable of raising your hair (literally!), sparking over whenever a Item No. Description
metal object is brought close to the needle, or any one of numerous C1 8-µF, 450-wVDC electrolytic capacitor.
pranks this infernal device is famous for. C2 .22-µF, 600 -volt molded capacitor.
C3 550-1700-pF timer capacitor.
The principle is simply one of creating a fantastically -high C4 82-pF, 3 -kV capacitor.
voltage capable of doing tricks only high -voltage can do, while C5 10-pF, 3 -kV capacitor.
retaining the safety factor of extremely low current generation. C6 0047 -µF,600 -volt mica capacitor.
L1 30-mH rf choke. (J. W. Miller 692 or
The only adjustment you'll have to make on this gadget is to equiv.)
tune C3 for maximum snapping and zapping. When the proper MI AC wall plug.
position is reached, you should see electric sparks pouring forth R1 51K resistor.
Si Spst switch.
from the point of the sewing needle, particularly when "drawn off' T1 High -voltage transf ormer. (J.W. Miller
by an item such as a screwdriver, etc. 4526 or equiv.)
Keep the length of heavy wire connecting the sewing needle T2 Transformer. (Thordarson 24R09U or TV
transformer with 120 -VAC .500 -VAC CT
with LI as short and perfectly straight as possible. It should not be and 6.3 -VAC filament windings.)
designed with the needle wire acting as a flexible cable for a shock VI 5Z4 tube.
rod regardless of how tempting such an idea might appear. The V2 5881 tube.
heavier and shorter that wire is, the more resultant zap. Have the
needle pointing straight up for best effect.
100
101
Electronic Thermometer For Liquids
Here is just the thing for making accurate liquid temperature
readings, particularly for amateur photographers' darkrooms
where it is difficult at best to read out degrees in Fahrenheit on a
mercury -type thermometer. The gadget shown in Fig. 44 provides
a close continuous check on the temperature of any liquid. Also,
see Table 44. When the temperature varies either above or below
where it should be, an alarm goes off in the form of a ticking relay. If
you like, you can rig up an external buzzer or bell (by hooking it into
the K3 relay contacts) to signal that something's gone amiss.
The probe that will be inserted into the liquid contains a
thermistor, as shown in the circuit diagram. It can be housed in a
hollow ballpoint pen, or whatever, so long as the thermistor wires
do not become shorted underwater. The thermistor itself, how-
ever, should touch the liquid at some point.
The circuit is not really complicated or difficult to put
together, although care should be taken during preliminary
adjustment. This procedure should be accomplished as follows:
Plug in the thermistor probe, set potentiometer R9 at minimum (to
the left), and turn R2 fully open (to the right). Now turn the power
on and gradually open R2 until you hear the relay clicking. At this
point it has probably told you that your room temperature is on the
order of 72 degrees Fahrenheit. Now advance R2 just a hair and
ajust R9 (to the right) until the clicking stops.
Next thing you will want to do is paste a piece of paper behind
the control knob (should be a pointer -type) of R2. You'll want to
mark the calibration points with a pencil as you proceed.
102 103
Table 44. Parts List for Electronic Thermometer for Liquids.
Item No.
Description
Cl 5-µF, 50-wVDC electrolytic capacitor.
Kl, K2, K3 DC relays. (Sigma 11F-9000-GiSIL or
equivalent.)
M1
9-VDC battery.
M2
33-VDC battery supply.
M3 6-VDC battery.
M4 6 -volt buzzer.
M5, M6
Test plugs, single -prong.
M7, M8 Test jacks.
M9
Thermistor. (Allied Radio 60 C8629 or
equiv.)
01, 02 2N321 transistors.
RI , R4 9.1K resistors.
R2, R9
R3
5K potentiometers.
3.9K resistor.
-EC? 45-Q
R5 6.8K resistor.
R6
R7
62K resistor.
75K resistor.
Portable Metronome
R8 1.1K resistor.
R10,R11 2.7K resistors. Here is a dandy transistor metronome which you can build into a
Si (A,B) Dpst switch. case as small as a tiny transistor radio, yet has all the features of the
professional models you frequently see on top of pianos. In fact, an
old nonworking transistor radio is the perfect housing for this
Now half fill a glass with room -temperature water and insert
gadget. In most cases, you can merely remove the main circuitry of
the thermistor probe and a conventional mercury thermometer. the radio but retain the following parts: the on -off volume control
Now add a little hot water until you hear the relay clicking again.
potentiometer, speaker, battery and battery holder, and speaker
Next, drop an ice cube and advance R2 until the clicking resumes.
transformer. If you have done this, you have just eliminated the
At this point, copy the temperature reading on the
mercury following items in the accompanying schematic: 6/4 ohm speaker,
thermometer on the homebrew dial -plate behind the pointer knob. Si, RI, Ml, and Tl. This leaves you with only four parts required
Now continue this procedure by dropping the ice cube back in
to build the portable metronome-the 8-µF capacitors and 25-µF
the water to a point where the temperature on the mercury capacitors, the 68K resistor, and the 2N105 junction transistor.
thermometer drops 2 degrees. Now advance R2 again until the See Fig. 45 and Table 45.
clicking begins, and mark this spot on the dial. Continue this Since costs were cut by eliminating the second transistor
cooling business until you have all the calibrations you want. (which would have acted as an audio amplifier), the portable
The finished product will be calibrated to react to any water metronome runs wide open in normal operation. As soon as S1 is
temperature you desire from about 58 to 86 degrees Fahrenheit. turned on, the metronome starts clacking. Control R1 determines
the "beat" or frequency of clacking to which you wish to set the
device.
To calibrate, merely synchronize your metronome with a
commercial type or with any known source-including a phono-
graph record. Once you have jotted down the main beats such as
"4/4" for four-four time, you're in business! If you're reworking a
transistor radio using its volume control for the clack -rate control,
you'll have to approximate settings or scratch markings on the side
of the radio case along with a "key" on the knob.
104
105
-2 46
Personal Electronic Dripolator
Fig. 45. Portable metronome.
Here is a gadget specially designed to convert sound sleepers to
Table 45. Parts List for Portable Metronome.
incurable insomniacs: a "drip, drip, drip" sounder guaranteed to
Item No. Description
drive your victim to distraction. Sort of a combination electronic
Cl metronome and transistor percolator, the circuit will power any
8-p.F, 25-w VDC electrolytic capacitor.
C2 25-µF, 25-wVDC electrolytic capaictor convenient 3.2 -ohm permanent -magnet speaker with sufficient
M1 9-VDC battery. volume to accomplish your purpose.
01 2N105 transistor.
R1
When S1 is flicked on, the dripping begins. You can adjust for
1-megohm potentiometer with spst switch.
R2 68K resistor. most effective drip -rate by setting R2 to the desired point. Other
S1 Spst switch on R1. variations can be achieved by trying substitutions for Cl.
T1 Transistor radio output transformer. (La-
fayette 99H 6123 or equiv.)
If a volume control is desired, add a 5K potentiometer
between the junction of C1 -Q1 -R1 and SP1-Ll. See Fig. 46 and
Table 46.
106 107
Fig. 46. Personal electronic dripolator.
47-Q
Table 46 Parts Listf or Personal Electronic Dripolator. Electronic Siren
Item No. Description Have you ever wondered how those police and emergency vehicles
Ci 4-ALF, 25-wVDC electrolytic capacitor.
are able to create such an ear-splitting attention -getter -sound as
C2 .15µF capacitor. they do with their sirens? They are really quite elaborate (and
C3 .22-µF capacitor. expensive), but if you would be willing to settle for a "manually -
L1 1 00-mH miniature choke (Lafayette Radio
34 H 8825 or equiv.) operated" version, you can construct this one.
01 GE -10 transistor. As S2 is slid into action, the wailing begins. A low -frequency
RI 1.1-megohm resistor.
R2
tone starts a shrill climb. (Incidentally, you can exercise some
15K potentiometer.
S1 Spst switch. control over this by substituting a 75K pot for R2). For the true
SP1 Any 3.2 -ohm permanent -magnet speaker. "siren" effect, merely depress Si and watch the action. The
X1 1 N38B diode.
climbing scream will suddenly reverse itself and start downward.
To repeat the procedure, depress Si again. After a few minutes'
practice, you will have no problem achieving true simulation of the
real thing.
If you like, you can install a volume control across the speaker
leads. A 5K potentiometer should do the job nicely. See Fig. 47 and
Table 47.
108 109
01
GE -3
02
TR-9
61 .022µF
Cl
SP1
62K
R2 75K
S1
50µF
SIREN SIMULATE
CONTROL
C2
-Q 48 -E;?
M1
S20 11111
9VDC Telephone Buzzer Toy
OFF -ON
At last here is a use for those surplus telephone dial mechanisms
Fig. 47. Electronic siren. just about everyone seems to have laying around gathering dust
these days. This clever little toy will provide hours of pleasure for
Table 47. Parts List f or Electronic Siren. all groups of youngsters, although it is perhaps most amusing to
children of ages two through five. The circuit contains no central
Item No. Description on -off switch, so it is always ready for action. It is impossible for
C1 .022-µF capacitor. the device to inadvertently be left on, draining the battery, since
C2 50-µF, 15-w VDC electrolytic capacitor.
M1
the telephone mechanism always returns on an "off' position by
9-VDC battery.
01 GE -3 transistor. itself. For these reasons, you should seldom have to replace Ml.
02 TR-9 transistor. Use a standard 6 -volt buzzer, available through most parts
Al 62K resistor.
R2 75K resistor..
stores or your local hardware shop. The bulb can be a regular No.
Si Push-button spst switch. 49 type (or whatever) 6.3 -volt filament lamp or a 6 -volt auto dash
S2 Standard spst slide switch. bulb.
SP1 Any 8 -ohm permanent -magnet speaker. Our suggestion is to build the buzzer toy into a sturdy wooden
box, brightly painted. Remember it's going to get knocked around
quite a bit, so make certain your batteries are securely locked into
position.
Incidentally, close inspection of Fig. 48 will reveal that a
jumper wire has been placed across the two upper terminals on the
dial mechanism. Make sure this wire is secured in place. Also, see
Table 48.
111
110
49
-EQ1
VLF Converter
Have you seen those gadgets which when placed next to your AM
radio convert it for eavesdropping on specific vhf channels? Well,
here's one that goes the other route -ultralow 200 -400 -kHz
eavesdropping-and it does not require your buying a crystal for a
specific frequency. Instead, you merely present it by tuning L2 to
Fig. 48. Telephone buzzer toy.
any VLF (very low frequency) signal. Next, place it next to your
Table 48. Parts Listf or Telephone Buzzer Toy.
AM radio, and presto!
The construction is not critical, although the recommended
Item No. Description coils should be installed and wiring made exactly as shown in Fig.
M1 49. Remove the aluminum can surrounding T1 and position the coil
6-VDC dry cells.
M2 6 -volt buzzer. similarly to however you elect to mount L2, although the two coils
M3 6 -volt pilot bulb. should be separated.
M4 Telephone dial mechanism. For tuneup, merely tape for external inductance coil (L3) to
the case of your transistor radio as close as possible to the AM
radio self-contained antenna coil. Now adjust the slug of L3 unit it is
about 3/4 inch outside of its coil form. Turn the power switch (S1) on
and adjust L2 until you hear a signal in your AM radio on an unused
frequency. Now adjust L3 and T1 for maximum reception.
You will find that you can "tune" the 200 -400 -kHz area by
simply tuning the AM radio in a normal fashion. If a broadcast signal
is encountered, readjust L2. Conversely, if you find a good blank
spot on the AM radio and wish to stay there, tune L2 to the desired
frequency in the 200 -400 -kHz band and then repeak T1 and L3 for
best overall performance at that frequency.
Incidentally, if you build your converter in a wooden or plastic
case, you will not have to make inductance coil L3 an external one.
Just move the converter next to the AM radio and position it for
best results.
A good external antenna and ground are a must for optimum
results. String a long wire between a few trees and you will be
surprised at the stations you will be able to hear.
112 113
1Pr
Appendix A
Substitution Guide
The following are standard substitutions for most of the major
components (tubes, transistors, and diodes) used in this book.
These substitutions have not been tried in the circuits and some
slight variation in circuit operation is possible and should be
expected. Some substitutions will probably improve overall
Fig. 49. VLF converter.
operation. Where no substitute is shown, no practical one was
Table 49. Parts Listf or VLF Converter. found. For general transistor substitutions see Table A-1.
The transistors listed in Table A-2 can be substituted for most
Item No. Description of those shown in Table A-1. In many cases it is only necessary to
Cl. C5, C6 .022-kiF capacitors. check polarity called for in the circuit to determine which universal
C2 500-pF capacitor. transistor can be used in a given situation. Also, see Tables A-3 and
C3 680-pF capacitor.
C4 75-pF capacitor. A-4.
L1 1-mH rf choke. (National R-50 or equiv.)
L2 455 -kHz oscillator coil. (Miller 2020 or Table A-1. General Transistors.
equiv.)
L3 Vari-loopstick. (Meissner 14-9015 or Substitute
equiv.) Type
M1 Binding post.
M2 9-VDC battery. 2N105 GE -2,2N107
Q1 GE -9 transistor. 2N109 2N217, 2N270, GE -2
R1 8.2K resistor. 2N188A 2N241A, 2N320, 2N321, 2N396A, N4148,
R2 1.1K resistor. 2N414C, GE -2
R3 110K resistor. 2N217 2N109, 2N466, GE -2
Si Spst switch. 2N278 GE -4
Ti 455 -kHz i-f transformer with built-in 2N280 2N1066, GE -2
capacitor. (Miller 2041 or equiv.) 2N297 GE -4, SK3009
2N319 2N320, GE -2
2N321 25A397, GE -2
2N331 2N396A, 2N414B, 26440A 26597, GE -2
2N397 2N1316, 2N1348, 2N1349,2N1354, 2N1355, GE -1
2N415 2N396A, 2N415A, 2N416,2N440, 2N44 OA, GE -1
2N517 2N1316,2N1969,GE-1
2N461 2N382, 2N383, 2N652, 2N1350, GE -2
2N555 GE -3
2N1177 GE -9
TI -415 TV -416, TI -419
114 115
-A-
Ir
v) 0) Cr) 741
0) 0) -iii0 C) co
00 X 03 CO S. N zz Mmmm00mm 000
mmm m=
co a) x K0 4 ,ie
= no cb 6 -:.1 (Jr e...) n.)
-0 4". 00 00) L ,,, .
-I 0[i3 W n., o 0
0) 0) 0) 0) 0) CF1 Z -0-13Z
ZZ z-om I)
1- X > D0 N -to m o -o -o o n = 13 -to
-0 - A crk ...n co < C)
oloPPI.?PEPPP%.9
-.I X * 3 co * :' 0, >>
-0 p -o
> >lo°'3 >-oco
P 99,
V>13 >to >
/3
g gt 2 n. ; g, rsi
,fx, -I"
@@@@ 2 5 al @ @ @ @
-: -ou,-,- --J
---2
ru 1.
-. > 4' 0I
g 3 3 50 0 Oi O nb o O Q 0
o .....1-" co OD OD M OD ye
.... M
J a. > CD .P. c 1'1 14 14 11? 1.1 P7 ..2 !"1 4".' RD
> g UP '-'
§ cu a) g
II
A n >00> 07..du 0t1 0 12
ii, iSi. j 2 S. 2 w, 3 g 0, 0, 8 E.',,
cp
a mCD 5 < = 113 < 5 8 :< 7
,c.
S 0cnko2 0 a- - g
(-) a
a 0, o) = 0.0.
-o 3 -0o 3o, 3.
P 3 =3,
v c ca -co 9, '
;( * P i-,
t' ci) 8. 2 th -,)
'.° 3 o,(0 < 13 -3 il,
.-
a) CD A 00 , op
ie O.f-0 (I) (I)
'4 0 a> ft) .R.S a
-4 (12
a) U1 C) P
CP .
-c
10 a
A 2 co
G) -6. 0
a. > c 3 3 3
:- D V -o
2.
Multiplier
tnd Signifkant TWur 001 -RANT SYSTT
10 SOntlkat Figure Tolerance
Multiplier
2nd SignIlkant Figure
III SOnillcant Figure Ist SWrillicant Figure
1st SIgnITICant iWur
2nd Signekani Figure 2nd Signilkant Figure
COLOR BAND SYS71 Tolerance
Blue CACCOD
1st SignIticonl figure 1st Significant Figure COMP -
Violet CL
COCO= -
CFO
- Sikeerable
White
Resistors WNh Black golly Color An Composition. Non insulated. Gold 0I 0%
Silver 0.01 t101
Resistors With Colored Bodies Are Conecnilion Insulated. I"
No Color
Wirneund R01,111ort 11aW The 1st Digit Color Band Double Width.
When used on corridor dion Actors, indicates percent failure per 1.000 hours. On libe resistors, a *tile thin band 'ndiCateS solder/be terminal
Table B-2. Capacitor Color Codes.
CO
DISC CERAMICS 5-00T sysnou CERAMIC CAPACITOR COORS I CAPACITANCE GIVEN IN PT I NIGH -CAPACITANCE TUNIAR CERAMICS
1st Significant INSULATED ON NONINSWATID
2nd SIgnIllunt COLOR DIGIT MULTIPLIER TOLERANCE TEMPERATURE EXTENDED RANGE
Figure Figure COEPErphilColcUIT IN SNnilicant figure 2nd Signiflunl Figure
TEMP. COM.
LESS 10 Pf SIGNI MULTI -
F IWO PLIER
ullipile FIGURE 110E10
BLACK D 1 57010
52.00 0 0.0 -I
BROWN I 10 ±0.1p1 5I% -13 -10
RED 2 IGO I 21 -Is 1.0 -100
Temperature Coefficient Tolerance Multiplier Tolerance Voltage 100ionall
ORANGE 3 10:0 10.230 12.W MO LS -IMO
MIMI 4 10013 -10000
-2202.2
DISC CERAMICS 0001 SYSIEM)nMPERATUR1 GREEN S -3)0 3./ COMPENSATING
±n IOW 1 TURINAR CERAMICS
IM SIgnifIcant 2nd Signifkant BLUE 6 .4E0 4.7 *10
Figure Figure VIOLET 7 -150 1,5 *ICC III Significant Firm ind Signilicant Et/ore
GRAY g .01 Y. 0.25, 30 1030
WHITE 0 .1 t LORI I 101 General Purpose 10003
SILVER Bypass I CeoPon9
Gimm
GOLD .100
*blob, will
E IA only. Ca ink Capacilor capacitor snoRab ratings re Hamlett SOO rolls, for some manulatureft, Temperature Callkient Multiplier loference
10:0 bits 10, other manufacturers, unless otherwise pecan/
MOLDEDINSWATILD AXIAL LEAD CERAMICS TYPOGRAPHICALLY MARKED CERAMICS MIL DEMON RANGE T. C. TUBULAR CERAMICS
TOLERANCE
LITTER
IN Significant Ebb irk Nnifkant Figure TemperatureCoeffichnt Capelt*nal ggpr oo LESS OVER tops 1st S0nItkant Figure Ind Signgicatil figure
C !O. 150
D ! OW Gimiri Tolerance
1111 1111111 F LON 2 If
G i 2.* ± PI
MullM TAMP MullIblitt Temperature CoeffkNnt Moh pier Tolerance Temperature Coeffklent
CO
While Rand Distinguishes Cabala From Resistor
0
begged From Soldered Surface
Tolerance MultIpbr
Table C-2. Semiconductors.
Appendix C
SEMICONDUCTOR DEVICES
Table C-1. Tubes.
®®e
METALLIC RECTIFIER BREAKDOWN
(SYMMETRICAL
ZENER DIODE)
DIODE TRIODE TETRODE PENTODE OR BEAM POWER
PENTODE
SHEET -BEAM
PN NP
NPN PNP
UNIJUNCTION UNIJUNCTION
GRID
NPN TETRODE
PNP TETRODE
PLATE
BEAM -
FORMING
PLATES PNPN
PNPN NPNP
EYE -TUBE (REMOTE BASE (REMOTE BASE (WITHOUT BASE
DEFLECTION CONNECTION) CONNECTION) CONNECTION)
PLATE
TRANSISTORS
121
120
Table C-3. Miscellaneous Symbols.
-r
A- B /TM
B
B
A© FIXED
Non.
VARIABLE Polarized polarized SPARK
ELECTROLYTICS PLATE DOUBLE
A A B A
-.- B SPEAKERS ELECTRO-
B - 54>i, STATIC
AND GATE TRANSDUCER
OR GATE NOT GATE
K 1K SINGLE
MICROPHONES STEREO
ONE-CELL MULTICELL
DETERMINING PHONO CARTRIDGES
RESISTORS AC VOLTAGE
SOURCES
f
COMPENSATING
Reset
Button \
r -0- -:
WIRES Male Female .
WIRES
CONNECTED WIRE i
CROSSING
CONNECTING :, 1 .."-
-0 0-
,
t- 1
INDUCTORS GROUNDS
t SHIELDS
/
i 1
LAMPS
AIR
CORE
POWDERED-
IRON CORE
IRON VARIABLE -®- MI SHIELDED
=i=
CORE CORE SHIELDED WIRE ASSEMBLY SHIELDED PAIR
FILAMENT
TRANSFORMERS
4
-4- -e-
NEON
JACKS
$
E
FUSES P-4f1
11
AIR CORE IRON CORE
1 1 AC RECEPTACLES
I F
METERS
+0 04 -0- -0-
POWER
AUTO-
TRANSFORMER
VARIABLE
CORE SHIELDED
I A-AMMETER
V-VOLTMETER
G-GALVANOMETER,
MA-MILLIAMMETER Non
Polarized
Ja
AA-MICROAMMETER polarized
122
123
Electronic chirper 23
parts list 24 Lamp, electric match -needing 98
Electronic dripolator 107 electric match -needing parts
parts list 108 list 99
Electronic fish lure 27 Light -ciphering machine,
parts list 28 long-distance 75
Electronic fl ash er, adjustable 77 long-distance parts list 76
parts list 78 Light organ, gypsy 87
Electronic metal locator 33 gypsy parts list 88
parts list 35 Lights, hi-fi color 89
Electronic rainmaker 91 hi-fi color parts list 90
parts list 93 Locator, electronic metal 33
Electronic rifle range 25 electronic metal parts list 35
parts list 26 Lock, combination electric 65
Index Electronic siren
parts list
109
110
combination electric parts list
Long-distance light -
66
Solenoid -operated door latch 65 parts list 72 best that have been published in meter able to detect the heat from
Stethoscope, electronic 51 Wireless transmitter, FM 38 Elementary Electronics Magazine a flashlight up to 12 feet away . .
electronic parts list 52 FM parts list 40 . projects that have been tested a moisture detector . .. an automatic
and proven! 256 pp., 256 illus. 7" x
night light .. . and more 140 pp.. 119
10". illus.
Paper $14.95 Hard $21.95 $8.95 Hard $14.95
Paper
Book No. 1999 Book No. 1992
BASIC ELECTRONIC TEST MASTER HANDBOOK OF
PROCEDURES -2nd Edition- ELECTRONIC TABLES Si
Gottlieb FORMULAS -4th Edition
The classic test procedures Here's YOUR SOURCE for
handbook, revised and expanded to fast, accurate, easy -to -use solutions
include all the latest digital testing to all the common-and not so
and logic probe devices! It covers common-electronics and related
the full range of tests and mea- math problems you encounter in
surements. Clearly spelled out everyday electronics practice! It's
techniques are backed up by ex- the complete revised, updated, and
greatly expanded new 4th edition of
planations of appropriate principles
and theories and actual test ex- a classic reference that's earned a
amples. Plus there are over 200 permanent spot on the workbenches
detailed show -how illustrations and of thousands of hobbyists and pro-
schematic diagrams. 368 pp., 234 fessional technicians. 392 pp., 246
illus. 7" x 10". illus.
Hard $23.95 Paper $13.95 Hard $21.95
Paper $16.95 Book No. 1625
Book No. 1927
126 alled by Roland Phelps
Other Bestsellers From TAB
"Z. DESIGNING AND BUILDING POWER SUPPLIES,
ELECTRONIC GADGETS, WITH SWITCHING REGULATORS, IN-
PROJECTS-Cart VERTERS AND CONVERTERS-
Chock full of electronics Gottlieb
gadgets and devices that really With such a large percentage of
work, this is a different kind of today's electronic equipment deriv-
project -building guide . not one
. .
ing their operating power from
that requires meticulous duplication regulated supplies using inverters
.
but one that otters a practical
. .
and converters, you owe it to
look at the "hows" and "whys" of yourself to stay in step with all the
electronic design, using a wealth of latest developments. This excep-
fascinating and workable applica- tional guide gives you all the
tions. You'll find the expert guidance technical data you'll need, from the
you need to make useful electronics basics of inverter, converter, and
devices and the inspiration you need switching -type power supplies, to
to devise your own new circuits and solid-state relays, logic -controlled
devices to conform to your specific supplies, cycloconverters, induction
needs and ideas! Hobbyists of all ex- heating methods, linear regulators,
perience levels will find this guide and much more! All the data and
unusually valuable! 406 pp., 214 hands-on guidance you need in one
illus. power -packed volume. 448 pp., 260
Paper $12.95 Hard $19.95 illus.
Book No. 1690 Paper $15.95 Book No. 1665
I. UNDERSTANDING ELECTRONIC
ELECTRONICS -2nd Edition DATABOOK-3rd Edition
Even more complete than the Make any electronic job easier
original edition that has been a and less time-consuming . . have.
Look for these and other TAB books at your local bookstore.
TAB BOOKS Inc.
P.O. Box 40
Blue Ridge Summit. PA 17214
Send for FREE TAB catalog describing over 1200 current titles in print.
49 MORE
Easy -To -Build Electronics Projects
by Robert M. Brown and Tom Kneitel
Looking for a super sourcebook of easy -and -fun -to -make elec-
tronics projects? Here's just the one you've been waiting for! It's
jam-packed with fascinating and entertaining projects, most of which
you can build in an evening and for less than $5.00! Beginners will
appreciate the simple, step-by-step directions, and every level of
hobbyist and experimenter will go for the unique and varied project
selections.
You'll be able to build fun things like an electronic rifle range,
just -plain -practical items like a fence charger or a solar TV reception
booster, and lots of gadgets from a transistor tickler to devices that
would make terrific school science projects (like a perpetual beeper).
There are experimental projects such as the electronic stethoscope, a
black -light projector that's guaranteed to make a hit with the kids, or an
electronic lure for the fisherman in the family. You'll find plans for a
practical pool splash alarm, a personal weatherman device, and a
variety of projects for the amateur radio enthusiast-a wireless mike,
an FM wireless transmitter, and a free -power AM radio receiver.
But wait! There's more to this book than projects! You'll get lots of
tips and hints on how to acquire needed parts at the lowest possible
cost . .
. even discover how to salvage parts from old radios and
television receivers. Plus, there's a section for beginners to get
them off to the right start, a handy parts substitution guide, resistor and
capacitor color codes, and a list of electronics symbols.
Robert M. Brown and Tom Kneitel are also co-authors of TAB's
101 Easy Test Instrument Projects and 49 Easy -To -Build Electronic
Projects.
OTHER POPULAR TAB BOOKS OF INTEREST
49 Easy -To -Build Electronic Projects (No. The GIANT Handbook of Electronic Circuits (No.
1337-$5.95 paper, $10.95 hard) 1300-$19.95 paper only)
The Second Book of Electronics Projects (No. The Master Guide To Electronic Circuits (No.
1317-$4.50 paper) 1184-$17.95 paper only)
TAB TAB BOOKS inc.
Blue Ridge Summit, Pa. 17214
Send for FREE TAB Catalog describing over 750 current titles in print.
o
-4 ;
A
CO
FPT » 6.95 ISBN 0-8306-1347-1 CO
rn
PRICES HIGHER IN CANADA 665-0981
CO