# 80-052

70 Watt Mono Power Amplifier Kit (audio amplifier)

# 80-055

PLL Tuned FM-Stereo Transmitter kit

# 80-057

PLL Controlled FM Stereo Transmitter kit (our best)

# 80-060

FM Stereo Transmitter kit

# 80-065

Wireless FM Mike kit

# 80-070

3-volt FM Transmitter/microphone kit

# 80-075

Tone-Volume-Balance Control kit (Hi-Fi project)

# 80-077 

DC Electric Motor Kit

# 80-080

Light Alarm Kit

# 80-082

UHF Remote (Radio) Controlled Relays Kit

# 80-085

Internet BROADCASTER FM Stereo Transmitter Kit

# 80-052, 70-Watt Mono Amplifier Kit

A POWERFUL amplifier with excellent quality output. The amplifier was designed for 12 to 14 volt DC use so that it could be powered from a car or truck battery for use during outdoor functions such as ballgames, picnics, and even during emergencies such as forest fires. Be sure to use adequate speakers; seventy watts is a lot of power. You could parallel two Philmore trumpet speakers no. WP- 20. Although rated at 30 watts each, they should be adequate unless you plan to turn the volume up all of the way and play hard rock (then, find bigger speakers). Designed for normal, line -level inputs such as CD Players, radios, but if the input will be a single microphone, you could use the 80-104 Stereo preamp and tie the two channels together (or use just one channel) as you will need a preamplifier for small inputs such as a magnetic mike. The preamp also operates on 12 volts. DC. Plan on using at least a 5 amp power supply if you don’t use on an auto battery; six or seven amps is better, or peaks may distort. The circuit has all the modern features, such as thermal shut down protection, output short protection etc.

# 80-055, PLL FM Stereo Transmitter Kit

Try this with your computer to re-transmit Internet radio! This is truly a slick product! The PLL (phase locked loop) tuning means stable broadcasting, which results in big advantages. Being on frequency and drift-free equals much better transmit distance and receive quality. Frequency is "entered-in" on a keypad, and the unit stays exactly on frequency. Transmit to your portable radio! For input use your CD player or tape player or your computer, so that you can broadcast programming on the Internet to your portable radio; listen anywhere around the home. Operates on 9 to 12 Volts DC.

# 80-057, PLL tuned FM stereo Transmitter Kit

Note that the "top board" is not shown here, just the bottom. The top board contains the digital readout and keypad. The top board, shown to your left, has the LCD digital readout plus the frequency entry keypad.

PLL controlled FM Stereo Transmitter Kit - top of the line. The finest in Stereo transmitters, and latest technology.  A 2 board FM Stereo Transmitter kit with the best possible features that our designers could think of. In addition to very clean, accurate stereo reproduction, the PLL tuning provides stability that is simply not available in most transmitters. Unit has an LCD display with an EEPROM memory to retain frequency setting even if powered down. Listen on your Walkman, or any stereo FM radio in your home or car. The top board is the controller, with the keypad switches and LCD readout. The bottom board is the transmitter, employing an NJM2035 for the stereo generator, buffered tuning from the PLL for quiet performance and an RF amp stage on the output. The circuit can be tuned in 5K steps, for fine tuning. You will want to use a very "clean" power supply for this circuit; batteries (12 volts DC, at least 75mA.) are a perfect source of power. Or, a well filtered power supply to be sure to eliminate power line hum. This circuit can broadcast any line-level input, such as a computer sound card, CD player, tape player etc. far enough to provide excellent reception around an average house and yard. Instructions for a low cost FM antenna are included. The top board size is 5 1/2" long and 3.3" in width; the finished unit fits neatly into a Philmore No PB170 plastic case (which is not in the kit, sold separately). The unit will function on voltages as low as 9 volts and as high as 14.9 volts; at the suggested 12 VDC the unit needs up to 75mA supply. While assembly is easy and straight forward, we suggest the kit only for builders with some experience in kit building.

# 80-060, FM Stereo Transmitter Kit

This is a circuit that will broadcast CD quality sound to your FM Walkman, home stereo or automobile radio. It produces a strong signal that will generally cover the average home and yard. It is stable enough to use even with digitally tuned FM receivers. Typical uses include broadcasting your own music to a receiver at poolside or in the garden. Or, you could broadcast from a personal, portable CD player to a car radio that has no CD player. School uses include running a "broadcast station" from another room as a speech class exercise. This unit is powered by a 9V transistor battery or you could use an AC wall adaptor.

# 80-065, Varactor Tuned FM Transmitter Wireless Mike Kit

This is the Cadillac of miniature, concealable FM transmitters, and wireless mikes. Transmits in the standard FM radio band; tune to open frequency. Varactor tuning results in stable signal, free from stray capacitance and drifting. Sensitive, picks up conversations from several feet. Powerful operation on a nine volt battery but could use 12V DC if you are going for distance. Easy to build, good for teaching beginners with just a bit of supervision.

# 80-070, 3-volt FM miniature Wireless Transmitter Kit

The most powerful circuit we’ve seen that operates on such low voltage (just two AA cells). A range of 100 meters can be expected and given a good antenna and good conditions, 500 meters is not unusual. Can be operated on up to about 9 volts. Transmits to the FM radio band. Teaches basics of transmitters. Microphone is included.

# 80-075, The Tone-Volume-Balance Control Kit

A serious audio (stereo) circuit; used much like a preamp (eliminates the need for one); that is, between the audio source and your stereo amplifier. Use with your amp or with our kit # 80-088, ten-watt stereo amplifier or with the No. 80-050 44-watt stereo amp (etc.). The kit has separate Bass, Treble, Balance and Volume controls; with loudness contour switch as well. Designed to run on 12 volts DC (@35mA), the circuit will work on "clean" DC voltage from 7.5 to 16 volts ("clean" means low ripple or using battery power). You will need to furnish the power supply and phono connector and/ or cables.

# 80-077, DC Electric Motor Kit

An introduction to the workings of an electric motor.  A few pieces of metal, some wire and then add your own 1.5 volt AA battery and the whole concept of what makes an electric motor run will be yours. A number of experiments are included in the instructions, which the teacher could use to get young minds really wrapped up in this project. Snaps together, no soldering required. (Kit shown in knocked-down form.) This one teaches some early concepts of electricity, magnetism and mechanics.

# 80-080, Light Alarm Kit

A sensitive photo Darlington transistor is used with CMOS NAND gate. The circuit detects light and triggers a siren. You could add your own triac or relay and switch practically anything. The kit uses the MEL12 Darlington super-alpha phototransistors, typically about ten times more sensitive than a normal phototransistor. The circuit usage includes burglar alarms, medicine cabinet alarm, automobile trunk alarm etc.

# 80-082, UHF Remote (radio) Controlled Relays Kits

Only the board is shown but kit does contain all component parts.

Two separate relays can be switched via encoded signals transmitted from a keychain size, two-button transmitter (like those used for car alarms and electric car doors). Push a button and relay toggles "closed" and one more push toggles it "open". Transmit distance is about 120 feet maximum. The receiver requires from 12 to 15 volts DC. The transmitter is supplied assembled and tested complete with its own battery. Tricky (receiver) parts of the circuit are supplied already assembled and tested; just plug them in and solder in place. Each relay can handle up to 10 amps @ 120V AC; plenty for numerous applications; control lights, door locks, magic shows etc.

# 80-085, "Internet Broadcaster" FM Stereo Transmitter Kit

Specifically for use with your personal computer, to re-broadcast in the FM band (stereo) the programs that you might listen to on the internet. This so that you could listen to programs or your music files from anywhere in the house or out in the yard. Simply plug this kit into the jack on the sound card of your PC and tune in any FM radio. Sound quality is VERY GOOD, close to tops, at a cost much less than line no. 80-055 kit (which outperforms them all). You can listen to CD’s too, of course, and now you don’t have to miss your favorite shows if you have your Walkman in your pocket and will be around your house or office. Plenty of power for most homes and around the yard. USE with 9 to 12 volt battery pack or an AC adaptor. The transmitter is not limited to use with a computer, of course. We know of a user that has it connected to a two-way (Ham) radio so that he can listen in to his station from around the yard using a Walkman. Add a couple of microphones with preamps, and you have a local area FM Broadcast station.

# 80-088 Stereo Amp Kit  (10 watt x 10 watt)

Employs the TDA2009 class AB audio power amplifier IC for quality stereo applications. May be operated on a supply voltage of 8 to 22 volts DC. This is a very straightforward stereo amplifier; complete with a PC board about (1-3/4" x 3"). Powerful enough to power your stereo for a mid-sized room and more than enough for use in a automobile.

# 80-090, Oscillator building blocks Kit

Build and experiment with astable, monostable and RS flip-flop multivibrators on one PC board with six LED’s. See and understand exactly how each works. This is a very educational kit and an excellent introduction to electronics. Operates on 9V battery.