14th December 2014
An electrostatic discharge wand with neon indicator lamp.
Parent article: Advent Calendar of Circuits 2014.
13th December 2014
A simple field mill made from PCB material and a small electric motor.
Parent article: Advent Calendar of Circuits 2014.
7th December 2014
The CAD files for the variable capacitor frame.
Parent article: Advent Calendar of Circuits 2014.
1st December 2014
Another year, another circuit project per day for 24 days!
Contains 3 sub-articles.
10th May 2013
A quick teaser video about my exhibit for Maker Faire 2013 in San Mateo.
1st December 2011
A circuit project per day for 24 days.
27th November 2011
I finally build Charles Wenzel's Curious C-Beeper capacitance probing tool.
10th July 2011
BPW34 photodiode based gamma radiation detector.
3rd July 2011
An AC ion chamber detector for alpha particles only.
7th May 2011
A quick video thanking everyone involved in the 555 contest using one of my prizes.
26th April 2011
Circuit diagram of the wireless power TX used in the video demonstration.
Parent article: Wireless Power Experiments.
19th March 2011
A simple direct-conversion receiver for the Homebrew Group challenge this year.
27th February 2011
A quick random dialling hack for the adding machine to demonstrate it at the Wyong Field Day.
Parent article: 555 Adding Machine.
26th February 2011
Decimal adding machine built using 102 LM555s and a decadic dialling mechanism from an old rotary dial telephone.
Contains 1 sub-article.
5th February 2011
Junkbox electrical component blinking 555/LED spider sculpture project.
30th January 2011
A relatively unconventional but simple design HF spectrum analyser utilising a super-regenerative VHF IF for its log detector. Candidate utility category entry for the March 2011 555 Contest.
16th January 2011
A bit of fun with LEDs, transistors and capacitors.
26th December 2010
Experiments in wireless power transfer for a practical application, lead to some interesting side-bar observations on plasma physics, and the cutest little Tesla coil you've ever seen.
Contains 1 sub-article.
27th November 2010
A simple picoammeter using an LMC662 op-amp.
14th November 2010
A relatively simple 11 transistor FM broadcast receiver using pulse-integration discrimination.
23rd October 2010
Simple blinkenlight project to Cylonify my workstation PC.
11th June 2010
A semi-finalised implementation of the passive air-band receiver and field testing while I was travelling in the US.
Parent article: Non-Emissive Airband Receiver.
23rd May 2010
An experimental solid-state Fremodyne AM/FM Receiver for VHF.
12th May 2010
More compatible receivers and a few circuits related to the system.
24th April 2010
The guts of an AFL Sports Ears receiver, what you get for your money and how to build or buy your own compatible receiver for significantly less.
27th March 2010
A tuned loop antenna with an active push-pull buffer featuring phantom powering via the coax feed.
7th February 2010
I build a variant of Roger G3XBM's latest experimental transceiver, the XBM80-2.
4th February 2010
Adventures in measuring the selectivity of MCU-controlled super-regenerative quartz crystal controlled receivers. Resulting in a very useful selective log power meter.
Parent article: MCU Controlled Super-regeneration with Quartz Oscillators.
1st February 2010
A RF power measuring head using the AD8307.
23rd January 2010
A low-speed data link implemented using Pierce quartz crystal oscillators controlled by a microcontroller.
Contains 1 sub-article.
4th January 2010
Arcing fault destroys the Rope Light controller.
Parent article: Rope Light Christmas Star.
27th December 2009
I put together a USB ISP programmer for use with my Win32 laptop.
25th December 2009
A simple 4 channel, PMW-controlled, 240 LED Christmas Tree.
Contains 1 sub-article.
20th December 2009
A charlieplexed 19 LED animated Christmas star for my Christmas tree.
13th December 2009
A proof-of-concept test bed for a range of animated electronic Christmas decorations.
7th June 2009
New pancake Geiger Müller tubes and a fairly small power supply for them.
31st May 2009
Pictures from the May 2009 ARNSW Trash and Treasure meeting.
24th May 2009
Abuse of an old 2X2 vacuum tube with a HT power supply to create a soft x-ray source.
16th May 2009
No, of course not! No new physics here, just another lesson in electromagnetic compatibility and subtly of experimental physics.
18th April 2009
A quick hack based on Charles Wenzel's nuclear war detector.
23rd March 2009
The beginnings of a photoplethysmographic cardiotachometer.
22nd March 2009
I finally assemble the bolometer sensor head into something resembling a completed unit.
Parent article: RF and Optical Bolometer.
18th March 2009
Gradual improvement of the bolometer baseline noise and the RS-232 sampler data capture system over several days.
Parent article: RF and Optical Bolometer.
1st March 2009
A multiplexed 7-segment digital display for the bolometer.
Parent article: RF and Optical Bolometer.
27th February 2009
A simple hack to interface an ATtiny13's ADC to the PC serial port for data logging.
25th February 2009
A thermal balance power meter for RF and Optical energy.
Contains 3 sub-articles.
16th February 2009
Tests of tinning various types of enamelled copper wire both from cut ends and through unbroken enamel.
Parent article: Wiring Pencil.
15th February 2009
A simple wiring pencil for digital circuit prototyping Verowire-style.
Contains 1 sub-article.
14th February 2009
An adapter for my ATtiny13 programmer so it can program ATtiny2313 devices.
Parent article: ATtiny13 Programmer.
14th January 2009
Another interesting Burkhard Kainka receiver circuit.
5th January 2009
A solid-state emulation of the infamous "dekatron spinner" implemented using a 10-stage discrete ring counter.
2nd January 2009
Using BJTs and LEDs to implement ring counters.
30th December 2008
A simple test circuit for assessing inductor core saturation and measuring inductance as a function of inductor current.
28th December 2008
I try my hand at designing a switchmode power converter for a B+ supply using an Atmel ATtiny13 for the controller.
14th December 2008
Building simple sawtooth oscillators with BJTs.
7th December 2008
Burkhard Kainka's super-regenerative FM receiver from Elektor September 2007.
23rd November 2008
A simple 100 kHz to 30 MHz sweep generator.
17th November 2008
A simple RF sniffer for detecting LF to SHF radiation.
26th October 2008
A Carver-style LC Test Device.
25th October 2008
A simple timber jig for winding 100 mm basket weave coils for MF work and investigations into coil Q and the Proximity Effect.
19th October 2008
Another wavemeter, this time for the lower half of VHF.
12th October 2008
An absorption wavemeter for HF having fairly good sensitivity.
11th October 2008
I finally get around to writing up the circuit diagrams from this old experiment.
Parent article: AM Walkie-Talkie Experiments.
28th September 2008
A simple coaxial feedline choke (aka braid-breaker) for antenna experiments.
23rd August 2008
A simple transformer-based -20 dB transmission line tap.
16th August 2008
I complete and box-up the QRSS beacon, and experiment with a vertical antenna.
Parent article: 30 Metre QRSS Beacon.
2nd August 2008
My slightly revamped return-loss bridge and using it for various measurements.
21st June 2008
A simple 1.5 Watt Morse beacon for 80 Metres.
Contains 3 sub-articles.
24th May 2008
A quickie showing what 400 NE-2 Neon glow lamps do if you put them in a microwave.
11th May 2008
A proof-of-concept POV display charlieplexing 6 LEDs.
4th May 2008
A step-counting pedometer which renders the step count as Morse Code for aural consumption.
3rd May 2008
I add a simple xtal clock source to the programmer.
Parent article: ATtiny13 Programmer.
3rd May 2008
A hack to unbrick ATtiny13s that you've stuffed up the fuses of.
19th April 2008
Simple parallel port programmer for the Atmel ATtiny13 (and similar ATtiny AVR range) chips.
Contains 2 sub-articles.
29th March 2008
A prototype tone-coded multi-channel remote control system.
23rd March 2008
Various toy AM transceiver circuits on 11 metres.
Contains 1 sub-article.
1st March 2008
Building a toy VHF phone transceiver for 3 metres using only one transistor for both TX and RX!
29th February 2008
Using the Negistor to implement a simple sidetone for minimalist QRP rigs.
27th January 2008
An interesting and quite useful autodyne receiver that phase locks the remote RF signal.
Contains 1 sub-article.
4th January 2008
Experiments with an RF degenerate parametric oscillator using several different non-linear devices.
31st December 2007
A discussion on how non-linear systems produce harmonic and intermodulation distortion.
30th September 2007
Another ARNSW trash and treasure day, including the Homebrew Group meeting with the display of the 80 metre challenge projects and a technical presentation on RF filters.
9th June 2007
My experiments with JFET biasing lead to a simple 455 kHz IF module.
27th May 2007
Some pictures from the 50th birthday party for the Dural VK2WI broadcast facility.
19th May 2007
Some experiments with the Foster-Seeley Discriminator and the Ratio Detector.
28th April 2007
Simple variable resistance and capacitance jigs for the bench.
4th March 2007
My implementation of Drew Diamond VK3XU's "Nano-L", plus how I constructed and trimmed my calibration inductances.
3rd March 2007
The circuit diagram for the transmitter so far.
Parent article: "2007 80m Homebrew Challenge".
22nd January 2007
My study of the VE7GC "Wee Willy" 80 metre DSB transmitter power amplifier.
20th January 2007
Another rotating multi-draw cabinet.
Parent article: Parts Cabinet.
11th November 2006
A simple filter-based SSB exciter. Still work in progress, but will some day become an SSB transceiver.
4th November 2006
An extremely useful RF sweep generator.
3rd September 2006
My implementation of Dick Cappels' simple RF Inductance Meter.
16th January 2005
Theory and practical electrical ignition circuits, e-matches, and pyrogens.
11th July 2003
Simple little parallel port breakout tool and software.
30th June 2003
A programmer for the AT89Cx051 series of microcontrollers. Uses the PC parallel port.
18th April 2003
A simple parallel port programmer for I2C 8-pin serial EEPROMs (24XX devices). It also works well as a general purpose I2C interface for your PC.
13th April 2003
My ugly implementation of Jens Dyekjĉr Madsen's PIC programmer.
6th April 2003
A simple VLF/ULF magnetic field probe for taking a quick aural measure of the local mains noise. It also works well as a cable-in-wall locator.
14th February 2003
A super simple inverter that will flash a neon brightly, powered by as little as a single 1.2 Volt rechargeable cell.
14th December 2002
A simple reflection-pair optical tachometer head for my CD structural integrity tests.
16th November 2002
An ultra-simple, very sensitive electrometer.
10th November 2002
My first meeting with Bill of SolderSmoke fame.
Parent article: Trivial Electric Motor.
3rd November 2002
A simple interface for picking up the audio on a phone line.
21st October 2002
Fooling around with a self-resonant long solenoid and modest RF power.
17th October 2002
A simple demonstration DC motor you can build in 10 minutes with your children.
Contains 1 sub-article.
24th September 2001
My bench amplifier that I use for listening to small AF signals.
31st August 2001
How I built my parts cabinet for all my electronic components.
Contains 1 sub-article.
3rd April 2000
A Linux driver for the Electronics Australia August 1996 Pocket Sampler project.
24th March 2000
My simple IR modem to let my computer talk to various consumer devices.