Test Equipment & Circuit schematics

• 10Hz - 100KHz D.D.S. Function Generator
• 2.5 GHz Frequency counter
• -20 dB Couplers for use with a with a spectrum analyzer or other sensitive detector
• -20 dBm, 14.060 MHz Precision Signal Source
• 220V live wire-in-wall scanner
• 250MHz RF Generator with 1kHz display resolution
• 3 in one tester (audio, tone generator, diode/circuit tester)
• 555 go / no-go tester
• 555 Timer IC Tester
• 5Hz to 500KHz frequency meter
• AD9850 DDS daughterboard
• Alarm circuit to remind you to turn off your DMM (digital multimeter)
• Audible Logic Probe based on LM339 operational amplifier
• Audio Millivoltmeter
• Audio Test Oscillator
• Automatic heat limiter for soldering iron
• Battery Tester for 1.5 and 9V
• BCD readout frequency counter
• Beeper to find short circuits
• Beeper to find short circuits (continuity tester)
• Build an inexpensive Hall effect Gaussmeter
• Capacitance meter
• Capacitance meter - precision meter for small capacitors
• Capacitance meter that connects to multimeter
• Connection tester for checking solder joints and other connections
• Conrad Electronics MM3610D multimeter cable pinout
• Contactless Mains Voltage Indicator
• Contactless Mains Voltage Indicator
• Continuity tester
• Continuity tester
• Continuity tester 2
• Continuity Tester based on 4 x 2N3904 and 1 x 2N3905 transistors
• Continuity tester using transistors
• Crystal tester
• Crystal tester that covers a range of 32kHz to 24MHz
• DCC Ammeter using ZXCT1009 current monitor
• DDS from 1-60 MHz with built-in amplifier and variable output level using Analog Devices AD9851
• Design for a slightly more expensive Gaussmeter
• Digital SWR / Power Meter
• Digital voltmeter (DVM)
• Digital Voltmeter using ICL7107
• Digital Wattmeter, measures from nanowatts to kilowatts using AD8307, PIC16F876, LCD Display
• Dip Oscillator for HF
• Distortion Analyser
• Elecraft XG2 receiver test oscillator (PDF)
• Electric field & leakage detector
• Electronic Circuit for Crystal Parameter Measurement
• EMF field probe (electromagnetic field probe) covering up to 100kHz
• ESR Meter
• Exclusive 2.5 GHz Frequency Counter with Blue 2x16 LCD display
• Field Strength Meter (FSM) covers 2Mhz - 1Ghz with peak reception at 3-200Mhz
• Field strength meter for the 137 kHz band
• Fixed Frequency "Tuner Dipper"
• Fluke 8010 / 8012 Interface
• Frequency and capacitance meter
• Frequency Counter / Timer / Logic Tester
• Frequency counter measures to 2.5 GHz and offers LCD display
• Full Featured Transistor Tester
• Function generator based on 555 timer and three 2N2222 transistors
• Function generator based on 8038PCD function generator IC
• Function generator based upon 8038 waveform generator IC
• Grid dip meter
• Ground Fault Indicator
• Heathkit signal generator user manual and circuit diagram
• High Impedance Voltmeter
• High Resistance Voltmeter
• Homebrew signal generator tunable from 3 to 30 Mhz
• Improved DCC Ammeter (2009) using Zetex ZXCT1009 current monitor
• In-circuit electrolytic capacitor checker
• In-circuit electrolytic capacitor tester
• Inductive meter adapter to measure inductance using a frequency counter
• Latching Continuity Tester to help find intermittent faults, has quite a few innovative features
• Latching continuity tester using 4093
• LC meter with LCD display for readout
• LCD Frequency Counter
• LCD frequency counter (PIC16F84)
• Led display digital Voltmeter using ICL7107
• Line Output / Flyback transformer tester
• Linear Resistance Meter
• Linear Resistance Meter
• Linear scale analog watt meter / RF power meter
• Live line detector
• Logic probe
• Logic probe
• Logic probe based on CMOS 4001 chip
• Logic probe with 7-segment display based on 74LS00 and 74LS47
• Logic probe with pulser
• Low Power Antenna Analyzer and ATU Tuning Aid
• Low-Cost Phase Noise Measurement
• Microphone Circuit Test Oscillator
• Mini DDS (direct digital synthesizer) using an Analog Devices AD9832 (12MHz maximum frequency)
• Mini tester: Handles continuity testing, resistor testing, capacitor testing and diode testing
• Miniscope - simple all-valve 1-inch CRT oscilloscope
• MOSFET tester for N-type MOSFET transistors
• MOSFET transistor tester
• Multi wire cable tester that handles up to eight conductors
• Multi-trace scope display that allows up to 4 channels to be viewed on a single oscilloscope channel
• Opamp Design and Test Board
• Optical ballistic chronograph for measuring projectile velocity
• Oscillopscope triggering circuit for recording long transients at fast sweep speeds (PDF)
• Oscilloscope testing module (huntron circuit)
• Oscilloscope testing module (Huntron circuit) that shows Lissajous patterns
• Panel Mounting Radio Frequency Counter
• PCB board tester and RF detector circuir diagrams
• PCB VSWR bridge
• Philips SB-6668 frequency counter upgrade
• PIC based frequency counter
• PIC logic probe with pulser
• PIC16F84 based diode tester
• Picoammeter circuit schematic with 4 ranges using CA3420
• Pink Noise Generator for Audio Testing
• Poor man's frequency counter
• Precision audio millivoltmeter
• Precision Frequency Marker
• Precision VXO for Crystal Characterization & Matching
• Pulse Reading Logic Probe
• Pulse Reading Logic Probe
• Quickie servo tester for testing servo motors (based on Atmel AT90S2343)
• RCM710 electronic scale, technical manual including schematic
• Resistor decade box
• Return Loss Bridge
• RF field strength meter
• RF Power Meter for the QRP measures up to 25 watts
• RF probe circuit diagram and Autotrax PCB layout
• Schematics and C code for a 0-5V PIC LCD volt meter
• Schematics and C code for a PIC frequency counter operating up to about 50 MHz (7 segment)
• Schematics and C code for a PIC frequency counter operating up to about 50 MHz (LCD)
• Self Oscillating Amplifier for Distortion Testing
• Self-powered Fast Battery-Tester - Tests 1.5 to 15 Volt cells
• Sensor to display, built with thermistor, 12-bit ADC, 89S52 and LED display
• Service monitor / deviation meter circuit
• Servo Motor Test Circuit (LM555)
• Signal Tracer and Injector
• Simple diagnostic tool for use on repeaters in the field
• Simple electronic S meter
• Simple Frequency Counter
• Simple Ground Loss bridge for Ground Loss Measurement at LF
• Simple Inductance Meter
• Simple light sensor adapter for oscilloscope
• Simple Ph Meter
• Simple polarity detector
• Simple Polarity Tester
• Simple test equipment to build
• Simplified Measurement of Output Impedance for Audio Circuits
• Single chip digital voltmeter using ICL7129
• Soft Power On Tester for Amplifiers
• Sound pressure level meter
• Spectrum analyzer Mk 1
• Spectrum analyzer Mk 2
• Square wave oscillator (555) for test applications
• Stereo Test Tone Generator
• Stereo Test Tone Generator
• SWR Bridge 1 to 1000 Mhz (1GHz)
• TDR cable reflection tester (Time Domain Reflectometer)
• TDS/PPM Meter for measuring of the amount of salts in a solution
• The u-counter, a PIC based programmable frequency meter (PDF)
• Thermistor Thermometer: LCD version
• Time Domain Reflectometer (TDR)
• TinyScope - simple all-valve 1-inch CRT oscilloscope
• Transistor tester and signal injector
• Transistor tester using 555 timer and 4027
• Triple Stroboscope
• True RMS Watt Meter
• TTL pulse counter/logic probe
• TTL Pulse Reading Logic Probe
• TXTVb - 70cm ATV Test Generator (PDF)
• UHF signal generator
• Ultra-simple Voltage Probe
• Ultra-simple voltage probe
• Universal frequency counter & voltage meter
• UTP Cable Tester
• VCR Tuner Based RF Spectrum Analyzer Schematic
• VHF signal generator
• Wire tracer
• Wireless Frequency counter
• XTal Tester for testing quartz crystals based on a pair of BC550C PNP transistors
• Z80 controlled Viscometer project
• Zener diode tester based on a 555 timer