from Wolfden Press - Page Three
Some Commercial Instruments that I use.
Page one contains Test and Measruement Instruments.
Page two contains Audio, Radio and Miscellaneous circuits
Some of these projects were gleaned out of my own experimentation while others are built from available kits.
Build at your own risk. Click most images for a larger view or schematic drawing of the circuit in PDF format.
Here is a small collection of Test Instruments that I have used in the past or I am still using.
Try the Capacitance Converter. Click Here, its on a separate page.
Siglent SDS 1052 Oscilloscope
Pictured here is the newest toy in my entourage of test instruments and gadgets to play with in my electronics lab. After years of using a not so reliable analog scope, I decided to try this. It is an amazing piece of equipment, a learning experience and a fascinating tool to use. The square wave shown here is from a few components I assembled on a breadboard to make a pseudo Bat Simulator. The wave is 40KHz (a little ripple on the top of the trace).
Instek SFG 1003 Function Generator
I think a new function generator is only in form with a new oscilloscope. I bought the 1003 as it meets my needs with a clean wave form in square, triangle and sine to 3 MHz. Also, it provides -5v to +5v offset, and duty cycle 25% to 75% adjustments. Needless to say, the economy of cost was a factor in choosing these instruments.
I have been using my Simpson 260 since before the age of digital multimeters. It provides accurate readings of voltage amerage and resistance. I like this analog meter especially for reading db and working on audio systems.
My little RS analog multimeter has been around for quite a while too. I used to carry it in my pocket so it was handy (hence, the crack in the lens). Even though it has limitations, it was always reliable. The only maintenance was the occasional battery change.
ELENCO Analog Meter M-1250
The Elenco meter is built from a kit. I did not need another meter but thought it would be fun to build one, it was. This one measures to: 1000 volts AC or DC, 10 amps, resistance to 10Meg and transistor hFE. I use it quite often in place of my digital meter.
This was my first digital multimeter. It was quite a treat to use after years of working the analog meters. The digits are small like the early digital calculators and watches. The PDM35 was made in England. When compared with modern day multimeters it shows very good accuracy.
The BK Precision Test Bench
When I first got this meter I used it mainly for measuring voltages. I did not even realize its capabilities. Soon I was measuring frequencies up to 200kHz and the value of small unmarked capacitors. The BK has become my standard for comparing the true reading of other instruments I've built.
Of all the Mastech meters this is the one that most suited my needs. The My69 is auto-ranging, it reads ac/dc volts and amps, resistance, capacitance, and frequency with duty cycle. Also, it reads transistor hFE. The display digits are easy to read and it will auto shut-off if not used for a while.
This is a BK Precision Model 3011 function generator. It produces square, triangle and sine waves from .2Hz to 2mHZ. Amplitude from 0 to 20 v p-p (open circuit) and up to 10 v p-p to a 50 ohm load. Offset is -10v to +10v and variable duty cycle from 1:1 to 10:1. TTL output is 3v p-p.
Here is another Digital Multimeter which I built as a kit from Elenco. It is not auto-ranging but is very fast in response. The kit quality is excellent with all high precision components.
DIY M12684 Transistor Tester
Although presented as a Transistor Tester this little character can test a multitude of components. Thus, I call it my Component Exlporer. Mine came as a kit from Banggood.com (China). I built it into an enclosure from Polycase, and mounted the ZIF socket on the case rather than the pc board.
Here is the assembled circuit as advertised.
And, the kit parts, including the ATmega328 microcontroller IC.
Click makes larger.
Elenco DT-100 Transistor Tester
This transistor tester is built from a kit. The indicators for good transistors are LEDs and the transistor quality is shown by the LED brightness. Also, it will test diodes. I found it a little tricky to use at first but with a some practice, it will give a good indication of the transistors tested.
With an oscilloscope you can not only look at the shape of electrical waves but read the amplitude and frequency as well. The oscilloscope is fundamental as a test instrument. This is a single trace scope so only one signal can be read at a time. This is a low cost scope but I think it looks good and it works good.
MFJ SWR Meter
The SWR (standing wave ratio) meter measures the output power of a radio transmitter. It will indicate the measured performance of the antenna. It is used to help design the antenna or adjust its length. This one is connected between the transmitter and the antenna coax cable. Also, it measures the output power in watts.
600LS Tone Test Set
This instrument is used to test and analyze telephone lines. It will generate a tracking tone, indicate polarity, capacitance in the line and test the integrity of the wiring. When used with a telephone test set, it is essentially a telephone "multimeter".
Tone Generator and Tracker
Here is a set that I have used extensively for tracing damaged telephone wiring in the crawl space of buildings. The tone generator is connected at one end and the tone can be heard by placing the probe near the wire, until a break is found.
ST-751 Signal Tracer
The signal tracer is used to inject a signal into a radio or amplifier circuit or it can trace the existing signal through the seperate stages. It generates a 1kHz pulsed tone at 1 volt amplitude. The trace signal is heard through a earphone.
The link Tester is actually a RJ11/RJ45 (wiring used for telephone and ethernet hookup) cable tester. Both ends of a cable are plugged in and the LEDs light in sequence indicating the integrity and polarity of the cable.
My Amprobe clamp-on ammeter. As its name implies, it measures Amperage or current draw from motors and almost any electrical device. It can be used at the circuit breaker panel or the location. With the included probes it will measure resistance and voltage.
My Wiggy is a standard tool of electricians. From working on high voltage motor control centers to just checking a duplex outlet, the Wiggy can be used to measure voltages safely. Its indicator is visual and convincing audio/vibrator.