CK003 10 Watt Audio Amplifier Kit $ 9.70
9986 Powerful Audio Amp & Intercom $10.90
CK265 MP3 / Walkman FM Mono Transmitter with Power Supply (Kit) $19.30
E-101-SP Space Explorer Solar Kit $22.90
R-SHA1C Stereo Headphone Amplifier Kit w/case $29.90
R-PH14C Peak Hold Dual Linear Bargraph Kit w/ case $34.90
R-PH15C Peak Hold Dual Log Bargraph Kit w/ case $34.90
R-PH16C Peakhold Dual Semi-Log Bargraph Kit w/ case $34.90



This compact audio amplifier uses the popular TDA2003 Integrated Circuit which can deliver over 10W of music power into a 4 Ohm speaker (7W R.M.S. / 4 Ohm or 4W R.M.S. / 8 Ohm). It incorporates a temperature compensation circuit so it is completely overload and short-circuit protected. 
Supply voltage: 12 to 18V DC / 0.5 to 0.75A Input sensitivity: 75mV / 47K Ohm Output power using 18V DC supply: Music Power: >10W / 4 Ohm RMS Power: 7W / 4 Ohm or 4W / 8 Ohm Frequency response: 20Hz to 20KHz (-3dB) Includes gold-anodized heat sink PC board dimensions: 1.7″ x 1.9″ (44mm x 49mm) 

“Electronics and Technology Educators:
Click here to join our Email list for monthly specials and product announcements!”

** 9986 Powerful Audio Amp & Intercom


Would you like to have a nice P.A. amplifier that you can use at home or in your car or van? This is the perfect one. It is also an intercom system that you can use in your Motor Home, home or truck. Perfect for club houses, etc. Ever want to yell at that ‘wreckless driver’ next to you. Well, here it is. This great amplifier will work on a 9 volt battery and it will work on the 12 volts in your car. You can use it as a SUPER SNOOPER to listen through wall too. Build one and let the fun begin! Comes with complete instructions.

Optional Clear Plastic Case 

CK265 – MP3 / Walkman FM Mono Transmitter with Power Supply (Kit)


This mono FM transmitter can be connected to any type of audio source with a headphone or line output such as a computer, laptop, portable MP3 Player, CD Player or Walkman in order to transmit the sound to any FM receiver. Another great application is to connect the circuit to your portable MP3 Player and listen to the music while in the car using your car’s FM radio. A car cigarette lighter adapter (CBL-12VCAR) is separately available specially for this application so that no batteries are required.

The circuit includes an stereo input which will mix the left and right stereo channels into a single mono signal. The transmitter is easily tunable on the entire FM commercial band (88 – 108MHz) using an adjustable coil and is very stable in frequency. 

The transmitter includes a stereo cable with plug for connection to your computer. The circuit can be powered with an adapter (we recommend using our 9V DC adapter DCA-9200) or using a car cigarette lighter adapter as mentioned above. A DC jack is incorporated right on the board for easy connection.

The transmitter incorporates a specially designed power supply which allows it to be connected to any standard 9V DC adapter without introducing the noticeable “hum” which is usually present when operating a low power transmitter through a wall adapter. The power supply uses two-stage filtering in conjunction with two RF chokes and bypass capacitors for best ripple rejection for a “hum” free operation.

Supply voltage: 9V DC adapter or 12V DC Incoporates stereo-to-mono input circuit Frequency adjustable: 88 to 108MHz Power consumption: 10mA Transmission range: approx. 150m (unobstructed) Input sensitivity: 300mV (Max) Includes stereo cable and plug



  • Stereo, 2 channels are displayed simultaneously
  • Each channel shows dual response-fast and slower peak hold
  • Linear, log, or semi-log response scales
  • Easy to set for AC, DC, power or voltage at virtually any level

The PH-14 series of LED bar graphs attack that problem head-on with impressive results. You can consider these bar graph units to actually be two complete LED bar graphs in one! There is the standard 10 segment bar graph with quick response, and a second set of circuitry expressly designed to catch the peaks and hold them for easy display. Let’s say you’re looking at audio going to your expensive speakers. You’ll see the LED display happily “bouncing” showing the average audio power, while one slower LED continuously shows the maximum power peaks. This type of display is very easy to follow and has the advantage of showing two results at once on the same LED bargraph! We offer 3 models of the PH series bar graphs: the PH-14 Linear display for voltage indication and general use, the PH-15 Logarithmic 3 dB/step model for audio and RF power displays and the PH-16 Semi-Logarithmic model, ideal for audio VU meters. All units are very versatile and can be set-up for AC or DC inputs and a variety of different signal levels. Complete instructions are provided for various applications and we even give you a selection of scales for your display. Power required is 7 to 15 volts DC. A handsome jet-black matching case set is available to finish off your project. Optional case size: 5”w x 11/2”h x 5 1/4”d.