Categories

Features

Everything!

14th December 2014

ACoC 2014: Day 14: De-shocker Wand

An electrostatic discharge wand with neon indicator lamp.

Parent article: Advent Calendar of Circuits 2014.

13th December 2014

ACoC 2014: Day 13: Field Mill

A simple field mill made from PCB material and a small electric motor.

Parent article: Advent Calendar of Circuits 2014.

7th December 2014

ACoC 2014: Day 7: Variable Capacitor

The CAD files for the variable capacitor frame.

Parent article: Advent Calendar of Circuits 2014.

1st December 2014

Advent Calendar of Circuits 2014

Another year, another circuit project per day for 24 days!

Contains 3 sub-articles.

10th May 2013

Maker Faire Bay Area 2013

A quick teaser video about my exhibit for Maker Faire 2013 in San Mateo.

7 comments.

1st December 2011

Advent Calendar of Circuits 2011

A circuit project per day for 24 days.

7 comments.

27th November 2011

The Curious C-Beeper

I finally build Charles Wenzel's Curious C-Beeper capacitance probing tool.

4 comments.

10th July 2011

Photodiode Gamma Ray Detector

BPW34 photodiode based gamma radiation detector.

33 comments.

3rd July 2011

Ion Chamber Alpha Particle Counter

An AC ion chamber detector for alpha particles only.

2 comments.

7th May 2011

555 Contest Thank You

A quick video thanking everyone involved in the 555 contest using one of my prizes.

4 comments.

26th April 2011

Wireless Power Demo Circuit

Circuit diagram of the wireless power TX used in the video demonstration.

Parent article: Wireless Power Experiments.

29 comments.

19th March 2011

ARNSW Homebrew Group 2011 Challenge

A simple direct-conversion receiver for the Homebrew Group challenge this year.

3 comments.

28th February 2011

CCARC Wyong Field Day 2011

Some video from the 2011 CCARC Field Day at Wyong.

2 comments.

27th February 2011

Random Dialler for 555 Adding Machine

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

555 Adding Machine

Decimal adding machine built using 102 LM555s and a decadic dialling mechanism from an old rotary dial telephone.

Contains 1 sub-article.

11 comments.

5th February 2011

555 Araneae Junkboxius

Junkbox electrical component blinking 555/LED spider sculpture project.

4 comments.

30th January 2011

555 Super-Regenerative IF HF Spectrum Analyser

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.

18 comments.

16th January 2011

Ring Oscillator Blinkenlights

A bit of fun with LEDs, transistors and capacitors.

8th January 2011

Alan's Crazy Ideas Episode #1: CT Scanning Khufu with Cosmic Rays

Idea of tomographic reconstruction of the internal structure of the Great Pyramid of Giza using cosmic ray muons.

9 comments.

26th December 2010

Wireless Power Experiments

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.

15 comments.

18th December 2010

TRON Backpack

Electroluminescent trimmed backpack inspired by TRON.

5 comments.

27th November 2010

Picoammeter

A simple picoammeter using an LMC662 op-amp.

5 comments.

14th November 2010

Pulse-Counting FM Broadcast Receiver

A relatively simple 11 transistor FM broadcast receiver using pulse-integration discrimination.

14 comments.

23rd October 2010

Larson Scanner

Simple blinkenlight project to Cylonify my workstation PC.

5 comments.

22nd August 2010

Winterfest Ham Radio Meet

Some pictures from the recent Winterfest HAM radio meeting.

3 comments.

11th June 2010

Non-Emissive Air-Band Receiver (Implementation & Use)

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.

18 comments.

5th June 2010

Strange Speed of Sound Result

I get oddly low results when attempting to measure the speed of sound in Water and Aluminium.

6 comments.

23rd May 2010

Fremodyne VHF AM/FM Receiver

An experimental solid-state Fremodyne AM/FM Receiver for VHF.

2 comments.

22nd May 2010

Helicopter Rescue at Queenscliff Headland

A short video of the daring helicopter rescue I awoken to this morning.

5 comments.

20th May 2010

Estimating The Size Of The ISS And STS

My quick go at estimating the size of the International Space Station and Space Shuttle Orbiter from the wonderful Thierry Legault solar transit photograph.

12th May 2010

More Sports Ears Related Musings

More compatible receivers and a few circuits related to the system.

9 comments.

24th April 2010

Sports Ears Broadcast Receivers

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.

17 comments.

27th March 2010

Phantom-Powered Active Loop Receive Antenna for 30 Metres

A tuned loop antenna with an active push-pull buffer featuring phantom powering via the coax feed.

2 comments.

13th February 2010

Half-life Of Technetium-99m

Measurement of the half-life of Technetium-99m.

6 comments.

7th February 2010

G3XBM's XBM80-2 Trivial 80 Metre CW Transceiver

I build a variant of Roger G3XBM's latest experimental transceiver, the XBM80-2.

2 comments.

4th February 2010

Quartz Oscillator Super-regenerative Receiver Selectivity Experiments

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.

6 comments.

1st February 2010

AD8307 RF Power Meter

A RF power measuring head using the AD8307.

3 comments.

23rd January 2010

MCU Controlled Super-regeneration with Quartz Oscillators

A low-speed data link implemented using Pierce quartz crystal oscillators controlled by a microcontroller.

Contains 1 sub-article.

10 comments.

4th January 2010

Rope Light Controller Failure

Arcing fault destroys the Rope Light controller.

Parent article: Rope Light Christmas Star.

6 comments.

28th December 2009

4-channel PWM Tree Emulator

A web-based emulator for the 240 LED Christmas Tree project.

Parent article: 240 LED Animated Christmas Tree.

2 comments.

27th December 2009

USBtinyISP Programmer

I put together a USB ISP programmer for use with my Win32 laptop.

1 comment.

25th December 2009

240 LED Animated Christmas Tree

A simple 4 channel, PMW-controlled, 240 LED Christmas Tree.

Contains 1 sub-article.

23rd December 2009

Rope Light Christmas Star

A large Christmas Star for my balcony made using a length of rope light and some timber dowelling.

Contains 1 sub-article.

20th December 2009

19 LED Animated Christmas Star

A charlieplexed 19 LED animated Christmas star for my Christmas tree.

4 comments.

13th December 2009

Charlieplexed 16 LED Animated Christmas Tree

A proof-of-concept test bed for a range of animated electronic Christmas decorations.

2 comments.

8th December 2009

LOL Can Christmas Tree

Some technical Yahoos assemble an office Christmas tree from over 430 soft drink cans.

1 comment.

7th June 2009

Pancake Geiger Müller Tubes and a new Power Supply

New pancake Geiger Müller tubes and a fairly small power supply for them.

12 comments.

2nd June 2009

June 2009 ARNSW Homebrew Group Meeting

Some photos from the June 2009 ARNSW Homebrew Group Meeting.

31st May 2009

May 2009 Trash and Treasure

Pictures from the May 2009 ARNSW Trash and Treasure meeting.

3 comments.

24th May 2009

Soft X-ray Output from a Vacuum Rectifier

Abuse of an old 2X2 vacuum tube with a HT power supply to create a soft x-ray source.

5 comments.

16th May 2009

Alpha Decay Rate Modulation with 30 Metre EM Radiation?

No, of course not! No new physics here, just another lesson in electromagnetic compatibility and subtly of experimental physics.

2 comments.

28th April 2009

Background Radiation Monitoring

I lash up an old Geiger tube and monitor the background radiation in the shack for a while.

18th April 2009

Ionisation Chamber Radiation Detector

A quick hack based on Charles Wenzel's nuclear war detector.

5 comments.

23rd March 2009

Homebrew Photoplethysmography

The beginnings of a photoplethysmographic cardiotachometer.

18 comments.

22nd March 2009

Bolometer Head Completed

I finally assemble the bolometer sensor head into something resembling a completed unit.

Parent article: RF and Optical Bolometer.

18th March 2009

Bolometer Baseline Noise Improvement

Gradual improvement of the bolometer baseline noise and the RS-232 sampler data capture system over several days.

Parent article: RF and Optical Bolometer.

6th March 2009

Hellschreiber QRSS

I implement sequential multi-tone Hellschreiber modulation in the 30 metre QRSS beacon.

Parent article: 30 Metre QRSS Beacon.

1st March 2009

Digital Display for the Bolometer

A multiplexed 7-segment digital display for the bolometer.

Parent article: RF and Optical Bolometer.

27th February 2009

RS-232 ADC Sampling Interface

A simple hack to interface an ATtiny13's ADC to the PC serial port for data logging.

2 comments.

25th February 2009

RF and Optical Bolometer

A thermal balance power meter for RF and Optical energy.

Contains 3 sub-articles.

4 comments.

24th February 2009

30 Metre QRSS Beacon Calibrated

I finally sit down and calibrate the front-panel controls of the QRSS beacon.

Parent article: 30 Metre QRSS Beacon.

16th February 2009

Solderability of Enamelled Copper Wire

Tests of tinning various types of enamelled copper wire both from cut ends and through unbroken enamel.

Parent article: Wiring Pencil.

4 comments.

15th February 2009

Wiring Pencil

A simple wiring pencil for digital circuit prototyping Verowire-style.

Contains 1 sub-article.

10 comments.

14th February 2009

ATtiny2313 Programming Adapter

An adapter for my ATtiny13 programmer so it can program ATtiny2313 devices.

Parent article: ATtiny13 Programmer.

29th January 2009

Variometer Prototype

A small variometer-style variable inductor as a prototype study of an interpolating inductor for an antenna matching unit.

7 comments.

25th January 2009

January Trash and Treasure

The Jan 2008 ARNSW Trash and Treasure, plus the Homebrew Group meeting.

3 comments.

14th January 2009

Emitter Follower Regenerative Receiver

Another interesting Burkhard Kainka receiver circuit.

10 comments.

13th January 2009

Antenna and Weather Station Work

I finally put up my discone antenna after many years of kicking it around the balcony and also install the weather station my parents gave me for my birthday.

10th January 2009

Mathias Katzar Builds One

Mathias Katzar builds an all-brass UHF Log-Periodic antenna.

Parent article: UHF Log-Periodic Array.

2 comments.

5th January 2009

Dekatron Emulator

A solid-state emulation of the infamous "dekatron spinner" implemented using a 10-stage discrete ring counter.

2nd January 2009

Discrete Ring Counters

Using BJTs and LEDs to implement ring counters.

2 comments.

30th December 2008

Inductor Saturation Tester

A simple test circuit for assessing inductor core saturation and measuring inductance as a function of inductor current.

4 comments.

28th December 2008

Switching Boost Converter Power Supply

I try my hand at designing a switchmode power converter for a B+ supply using an Atmel ATtiny13 for the controller.

2 comments.

23rd December 2008

Fixed the MFJ-207 FM Problem

A two-component fix for the rail-to-rail oscillation of the ALC loop op-amp.

Parent article: MFJ-207 Review.

2 comments.

20th December 2008

MFJ-269 Review

Peter VK2TPM loans me his MFJ-269 to try out.

5 comments.

14th December 2008

Discrete Sawtooth Oscillators

Building simple sawtooth oscillators with BJTs.

12 comments.

7th December 2008

Elektor FM Broadcast Super-Regenerative Receiver

Burkhard Kainka's super-regenerative FM receiver from Elektor September 2007.

13 comments.

2nd December 2008

Spam OK in AU - Just become a Political Party

I complain in vain to ACMA about spam from Citizens Electoral Council of Australia...

3 comments.

23rd November 2008

Heterodyne Sweep Generator

A simple 100 kHz to 30 MHz sweep generator.

8 comments.

22nd November 2008

MFJ-207 Review

My take on the MFJ-207 HF antenna bridge.

Contains 1 sub-article.

5 comments.

17th November 2008

RF Sniffer

A simple RF sniffer for detecting LF to SHF radiation.

27 comments.

26th October 2008

Inductor and Capacitor Measurement Fixture

A Carver-style LC Test Device.

4 comments.

25th October 2008

Basket-Weave Coil Jig

A simple timber jig for winding 100 mm basket weave coils for MF work and investigations into coil Q and the Proximity Effect.

11 comments.

19th October 2008

VHF Wavemeter

Another wavemeter, this time for the lower half of VHF.

5 comments.

18th October 2008

Website Changes

New "clean" URLs for the website and a new calculator engine.

4 comments.

12th October 2008

HF Wavemeter

An absorption wavemeter for HF having fairly good sensitivity.

11th October 2008

Circuit Diagrams for the AM Walkie-Talkie Experiments

I finally get around to writing up the circuit diagrams from this old experiment.

Parent article: AM Walkie-Talkie Experiments.

4 comments.

28th September 2008

Resonant Coaxial Feedline Choke

A simple coaxial feedline choke (aka braid-breaker) for antenna experiments.

2 comments.

23rd August 2008

-20 dB Tap Attenuator

A simple transformer-based -20 dB transmission line tap.

20th August 2008

Antenna Experiments are Great Teaching Aids

Some recent erudition from experiments on the 30 metre antennas.

16th August 2008

30 Metre QRSS Beacon Updates

I complete and box-up the QRSS beacon, and experiment with a vertical antenna.

Parent article: 30 Metre QRSS Beacon.

2 comments.

10th August 2008

30 Metre QRSS Beacon

I get a basic QRSS beacon going on 30 metres.

Contains 3 sub-articles.

4 comments.

3rd August 2008

Beacon Reports

Summary of the reports received for the 80 metre beacon experiment.

Parent article: 80 Metre CW Beacon.

3 comments.

2nd August 2008

Return Loss Bridge

My slightly revamped return-loss bridge and using it for various measurements.

7 comments.

27th July 2008

ARNSW Trash and Treasure

Lots of pictures from the ARNSW Trash and Treasure and Homebrew Group meeting.

3 comments.

27th July 2008

Killarney Heights Space Program

I attend a Killarney Heights Space Program launch.

13th July 2008

New Beacon Antenna

I finally rig up a vertical antenna for my 80 metre CW beacon.

Parent article: 80 Metre CW Beacon.

10 comments.

4th July 2008

Measuring Your Hair Diameter

How to quickly measure the diameter of human hair...

29th June 2008

More Beacon Work

I put the 80 metre beacon in a box and do some more work towards an antenna for it.

Parent article: 80 Metre CW Beacon.

14 comments.

21st June 2008

80 Metre CW Beacon

A simple 1.5 Watt Morse beacon for 80 Metres.

Contains 3 sub-articles.

6 comments.

1st June 2008

Rotifers in my Rain Gauge

Images of various microscopic life from my rain gauge.

4 comments.

24th May 2008

Neon Bulbs in a Microwave

A quickie showing what 400 NE-2 Neon glow lamps do if you put them in a microwave.

4 comments.

11th May 2008

Charlieplexed Persistence of Vision Counter

A proof-of-concept POV display charlieplexing 6 LEDs.

1 comment.

4th May 2008

Pedometer with Morse Interface

A step-counting pedometer which renders the step count as Morse Code for aural consumption.

2 comments.

3rd May 2008

ATtiny13 Programmer Gets a Clock Source

I add a simple xtal clock source to the programmer.

Parent article: ATtiny13 Programmer.

2 comments.

3rd May 2008

ATtiny High Voltage Programmer

A hack to unbrick ATtiny13s that you've stuffed up the fuses of.

3 comments.

27th April 2008

PSK-31 Beacon Mark 2

More progress on the PSK-31 beacon.

Parent article: PSK-31 Beacon Mark 1.

2 comments.

20th April 2008

PSK-31 Beacon Mark 1

Prototype PSK-31 Beacon Keyer.

Contains 1 sub-article.

2 comments.

19th April 2008

ATtiny13 Programmer

Simple parallel port programmer for the Atmel ATtiny13 (and similar ATtiny AVR range) chips.

Contains 2 sub-articles.

9 comments.

18th April 2008

Tone Dipper Update

Better circuit diagram drawing for the super-regen tone dipper.

Parent article: Super-Regenerative Tone Dipper.

12th April 2008

PSK-31 Interface for the FT-817

My simple, fully isolated, audio keyed, PSK-31 interface for my FT-817ND.

3 comments.

29th March 2008

RF Remote Control Experiments

A prototype tone-coded multi-channel remote control system.

3 comments.

23rd March 2008

AM Walkie-Talkie Experiments

Various toy AM transceiver circuits on 11 metres.

Contains 1 sub-article.

12 comments.

8th March 2008

Bicycle Rim Antenna for 20 Metres

A small transmitting loop antenna for 20 metres using a Aluminium bicycle wheel rim.

9 comments.

1st March 2008

One Transistor Voice Transceiver

Building a toy VHF phone transceiver for 3 metres using only one transistor for both TX and RX!

8 comments.

29th February 2008

Negistor Applications

Using the Negistor to implement a simple sidetone for minimalist QRP rigs.

9 comments.

4th February 2008

Autodyne Receiver Now In a Box

I add a front-end and a box to the 30 Metre Autodyne Receiver

Parent article: 30 Metre Autodyne Receiver.

1 comment.

27th January 2008

30 Metre Autodyne Receiver

An interesting and quite useful autodyne receiver that phase locks the remote RF signal.

Contains 1 sub-article.

8 comments.

26th January 2008

Australia Day 2008

Some images and words from this Australia Day.

2 comments.

20th January 2008

HAARP/LWA EME Listening

The HF Active Auroral Research Program conducted Luna bounce experiments on the 19th and 20th. I listened in.

2 comments.

17th January 2008

What's going on with Tcard?

That on-again, off-again disaster sited on ancient Sydney buses.

1 comment.

4th January 2008

Parametric Oscillator Experiment

Experiments with an RF degenerate parametric oscillator using several different non-linear devices.

3 comments.

31st December 2007

Non-Linearity, Harmonic Generation and Frequency Mixing

A discussion on how non-linear systems produce harmonic and intermodulation distortion.

1 comment.

30th December 2007

Cellular Automata Applet

A fairly trivial Cellular Automata implementation as a Java Applet.

24th December 2007

Cellular Automata Hardware Ideas

Thoughts about building cellular automata in hardware.

22nd December 2007

Various Pictures

Some images from my many cell runs and experiments with purification of pyrotechnic oxidisers.

Parent article: Making Chlorates and Perchlorates.

50 comments.

20th December 2007

Comment System Added

This website now supports reader feedback via a comment posting system.

8 comments.

20th December 2007

WikiText Primer

What is wikitext?

18th December 2007

Receiver Boxed Up

I put the regen-o-reflexive receiver on 31 metres and put it in a box.

Parent article: Regenenerative-Reflexive Receiver.

8 comments.

17th December 2007

MathML Support Added

I add MathML support to this site using ASCIIMathML.

2 comments.

16th December 2007

HF Receiving Loop

Some experiments with a tuned receiving loop for HF.

12th December 2007

The Agony of the About Me page

I try to write an "about me" page.

8 comments.

9th December 2007

Another Site Rewrite

The website has been rewritten to support categorisation and given a much needed face-lift.

4th November 2007

Regenenerative-Reflexive Receiver

An interesting detector idea from PA2OHH.

Contains 1 sub-article.

3 comments.

21st October 2007

DX-pedition with Peter VK2TPM

Peter and I take some assorted radios and antennas to the Fairfax Walking Track at North Head NSW.

2 comments.

30th September 2007

ARNSW Trash and Treasure

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.

2 comments.

22nd September 2007

Super-Regenerative Tone Dipper

A super-regenerative dip meter that is extremely sensitive and easy to use.

Contains 1 sub-article.

4 comments.

16th September 2007

Tone Dipper

A simple dip meter using an audio tone as the read-out mechanism instead of a moving coil meter.

2 comments.

16th September 2007

Nano-Henry Meter Counter Adapter

A simple but useful nano-Henry inductance meter adapter for your frequency counter. Doubles as a capacitance meter and stability assessment device.

9th September 2007

Multimeter RF Power Add-On

A simple 50 Ohm power meter adapter for a multimeter. (Also talks about my diode probe.)

4 comments.

8th September 2007

Micropower FM Broadcast Receiver

A simple minimum-component super-regenerative receiver for the FM broadcast band.

29 comments.

17th July 2007

The "Noisy Regen"

A regenerative receiver based on an emitter-coupled oscillator topology of elegant simplicity but fairly average performance.

7 comments.

14th July 2007

Non-Emissive Airband Receiver

Experiments with Charles Wenzel's "Passive Aircraft Receiver" circuit.

Contains 1 sub-article.

2 comments.

9th June 2007

Biasing JFETs, AGC IF and other fun

My experiments with JFET biasing lead to a simple 455 kHz IF module.

7 comments.

3rd June 2007

Plumbing MacGyver Style

How I fixed my toilet cistern inlet valve with a Coke bottle cap.

2nd June 2007

End-Fed Half-Wave for 2 Metres

A quickie hack that actually worked pretty well.

4 comments.

27th May 2007

VK2WI 50th Field Day

Some pictures from the 50th birthday party for the Dural VK2WI broadcast facility.

26th May 2007

Twinlead Velocity Factor

A twinlead j-pole design for 2 metres gives rise to measurements of velocity factor for VK-available twinlead.

1 comment.

26th May 2007

The Fredbox

A very simple 2 metre AM transceiver from Roger Lapthorn G3XBM.

1 comment.

19th May 2007

FM Detection Experiments

Some experiments with the Foster-Seeley Discriminator and the Ratio Detector.

5 comments.

28th April 2007

"C" and "R" Jigs

Simple variable resistance and capacitance jigs for the bench.

2 comments.

15th April 2007

The PNP-80 Receiver

An 80 metre super-heterodyne SSB receiver built using BC556 devices only.

1 comment.

24th March 2007

MK484 MW Receiver

A fairly small MK484 based receiver for the AM broadcast band.

6 comments.

11th March 2007

End-Fed Half-Wave Antenna & Tuner

My cute little EFHW tuner with in-built VSWR bridge.

5 comments.

4th March 2007

Nano-Henry Inductance Meter

My implementation of Drew Diamond VK3XU's "Nano-L", plus how I constructed and trimmed my calibration inductances.

1 comment.

3rd March 2007

Circuit Diagram

The circuit diagram for the transmitter so far.

Parent article: "2007 80m Homebrew Challenge".

1 comment.

25th February 2007

Exciter in a Box

I put the 4 Watt exciter in an Aluminium box.

Parent article: "2007 80m Homebrew Challenge".

24th February 2007

4-5 Watts PEP

IRF510s arrive and I build a TX power-chain.

Parent article: "2007 80m Homebrew Challenge".

2 comments.

18th February 2007

Wyong and Receiver Thoughts

I go to the CCARC field day and think about different RX topologies.

Parent article: "2007 80m Homebrew Challenge".

17th February 2007

A Working Receiver

I get the TX talking to the RX and true First-Light for the Receiver.

Parent article: "2007 80m Homebrew Challenge".

2 comments.

7th February 2007

AM Receiver IF Development

I start building the RX side of things.

Parent article: "2007 80m Homebrew Challenge".

1 comment.

5th February 2007

Building the AM Modulator

I build the AM exciter, including crystal oscillator and speech amp.

Parent article: "2007 80m Homebrew Challenge".

31st January 2007

A3E Modulation

I decide on low-level AM modulation, design and breadboard an AM modulator.

Parent article: "2007 80m Homebrew Challenge".

28th January 2007

I Visit ARNSW

Clarification on the Challenge requirements means a completely different approach.

Parent article: "2007 80m Homebrew Challenge".

24th January 2007

1 Watt DSB Transmitter

I complete a 1 Watt DSB transmitter lash-up.

Parent article: "2007 80m Homebrew Challenge".

2 comments.

22nd January 2007

The "Wee Willy" RF Power Amp

My study of the VE7GC "Wee Willy" 80 metre DSB transmitter power amplifier.

4 comments.

21st January 2007

Switched Attenuator

A basic 50 Ohm switched attenuator.

20th January 2007

Parts Cabinet (Mark II)

Another rotating multi-draw cabinet.

Parent article: Parts Cabinet.

14th January 2007

VK2ZOI Flower-Pot Antenna

My experiments with the VK2ZOI Flower-Pot antenna for 2 metres.

13th January 2007

VHF Impedance Bridge

A very easy to get going VHF impedance bridge for antenna work.

3 comments.

13th January 2007

"2007 80m Homebrew Challenge"

My work towards the ARNSW Homebrew Group's "2007 80m Homebrew Challenge" transmitter project.

Contains 11 sub-articles.

13th January 2007

Initial Thoughts

I first read about the challenge on the ARNSW website.

Parent article: "2007 80m Homebrew Challenge".

7th January 2007

VXO 80 metre receiver

A simple direct conversion receiver for 80 metres using a ceramic resonator VXO.

9 comments.

18th November 2006

40 Metre Spectrum Analyzer

My go at making a JF1OZL-style spectrum analyser for 40 metres.

1 comment.

11th November 2006

SSB Exciter

A simple filter-based SSB exciter. Still work in progress, but will some day become an SSB transceiver.

2 comments.

11th November 2006

FM Broadcast Receive Antenna

A quick folded dipole antenna for 3 metres.

4th November 2006

RF Sweep Generator

An extremely useful RF sweep generator.

11 comments.

3rd September 2006

Inductance Meter

My implementation of Dick Cappels' simple RF Inductance Meter.

4 comments.

2nd September 2006

Active HF Probe

My copy of VK5BR's sweeper detector.

13th August 2006

Regenerative FM Broadcast Receiver

My implementation of Francis Hall's "Euro Set".

10 comments.

6th August 2006

MW Regenerative Receiver

A simple 3-transistor regenerative receiver from the MW broadcast band.

7 comments.

12th February 2006

Alan's Tips

Hard-won experience with the processes of making Chlorate and Perchlorate on a small "kitchen windowsill" scale.

Parent article: Making Chlorates and Perchlorates.

3 comments.

30th July 2005

Making Magnalium

Open-crucible alloying of pyrotechnic Magnalium.

11 comments.

9th July 2005

Reverberatory Furnace

My simple "tub" reverberatory furnace for scrap melting.

3 comments.

18th June 2005

Crucible Furnace

A basic 150 mm bore crucible furnace.

2 comments.

5th June 2005

Trial Furnace

Small furnace to teach myself refractory material handling and usage.

2 comments.

4th June 2005

Propane Burner

A simple naturally aspirated 20 mm propane burner for my furnace experiments.

2 comments.

21st March 2005

Qualitative Composition Analysis

How to determine the components of a given composition.

20th March 2005

First Try at Perchlorates

My first attempt at making Potassium Perchlorate.

Parent article: Making Chlorates and Perchlorates.

7 comments.

5th March 2005

Platinum Anode

A run with a Platinum anode.

Parent article: Making Chlorates and Perchlorates.

10 comments.

5th March 2005

Hydrometer

An incredibly crude soda straw hydrometer.

28th February 2005

Black Powder Moistening

Is dampening your BP helpful or harmful?

10 comments.

18th February 2005

Thermal Decomposition of Calcium Hypochlorite

Or how to almost gas yourself for less than a tablespoon of KClO3.

Parent article: Making Chlorates and Perchlorates.

8 comments.

18th February 2005

Ferro-Gallotannic Ink

Iron gall ink and a bamboo pen of sorts.

2 comments.

15th February 2005

Flame Test Loop

How to make your own flame test tool.

2 comments.

13th February 2005

Making Chlorates and Perchlorates

My adventures in practical pyro oxidiser preparation.

Contains 6 sub-articles.

6 comments.

13th February 2005

My First Try

My first attempt at making Potassium Chlorate electrolytically.

Parent article: Making Chlorates and Perchlorates.

8 comments.

10th February 2005

Site Rewrite

I finally got around to that CMS conversion.

2 comments.

16th January 2005

Electrical Ignition

Theory and practical electrical ignition circuits, e-matches, and pyrogens.

2 comments.

27th January 2004

PyroSim

A simple particle system simulation for making fireworks-like animations.

3 comments.

21st December 2003

A Reliable BP Rocket

My work-horse payload lifting rocket motor design, which has proven itself fantastically reliable.

19th November 2003

Fireworks That Spin

Rotating devices that are amongst my favourite devices to build and shoot.

3 comments.

8th November 2003

Spin-Stabilised Rockets

Rockets that fly without sticks or fins.

9 comments.

29th August 2003

Take-tonbo

An ancient Chinese invention, the Bamboo Dragonfly.

2 comments.

13th August 2003

Plasma Cup Inverter

Just what is inside those neat Neon plasma drinking cup things.

3 comments.

9th August 2003

Fuse Making

How I make the various kinds of ignition materials I use.

6 comments.

2nd August 2003

Ball Mill

A small ball mill for crushing and mixing.

45 comments.

11th July 2003

Parallel Port Breakout

Simple little parallel port breakout tool and software.

30th June 2003

Atmel AT89Cx051 Programmer

A programmer for the AT89Cx051 series of microcontrollers. Uses the PC parallel port.

10th June 2003

Cabbage Indicator

Using red cabbage juice as a cheap homebrew pH indicator.

2 comments.

8th June 2003

Pinhole Projector

A cardboard box pinhole camera that operates without film. The image is projected onto a screen for human observation. A quick and simple project to demonstrate pinhole optics.

10th May 2003

Diagram Error

Fred Kennedy noticed the circuit diagram might be wrong.

Parent article: High Voltage Probes.

2 comments.

10th May 2003

Another VHF Super-Regenerative Receiver

A new VHF super-regenerative receiver designed specifically for the FM broadcast band. The design is IC-free, built from bipolar and field effect devices only.

2 comments.

18th April 2003

Serial EEPROM Programmer

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.

10 comments.

14th April 2003

Tjerk Schuringa PE9ZZ writes

Parent article: UHF Log-Periodic Array.

2 comments.

13th April 2003

PIC Programmer

My ugly implementation of Jens Dyekjĉr Madsen's PIC programmer.

1 comment.

6th April 2003

Mains Hum Survey Probe

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.

4th April 2003

The Big Loop Project

Going LF/VLF/ULF with a large multi-turn loop.

2 comments.

24th March 2003

The Piñata From Hell

A Piñata the girlfriend and I built for her birthday party.

1 comment.

20th March 2003

Circuit Diagram

Richard Solis asked me to post the circuit diagram.

Parent article: High Voltage Probes.

14th February 2003

Neon Flasher

A super simple inverter that will flash a neon brightly, powered by as little as a single 1.2 Volt rechargeable cell.

1 comment.

9th February 2003

Quickie Marx Generator

Built to show ceramic caps are generally OK for Marx service.

Parent article: Marx Generator.

1 comment.

28th January 2003

Knowing Your Coronatron

Characterizing the testing supply, and some more thoughts towards building "the big one" some day.

Parent article: Marx Generator.

27th January 2003

A Bigger Marx Generator

More new capacitors lead to a multi-Joule device.

Parent article: Marx Generator.

4 comments.

14th January 2003

Choke Charging Experiments

An attempt at a choke charging Marx generator.

Parent article: Marx Generator.

5th January 2003

More Marx Generators

Two new prototypes for the New Year.

Parent article: Marx Generator.

2 comments.

22nd December 2002

Plasma Diode Detector

Demodulation of microwave radiation using a Neon plasma.

2 comments.

14th December 2002

Structural Integrity of CDs

Just how fast can you make a CD-ROM or DVD drive before the CD media fails?

2 comments.

14th December 2002

Optical Tachometer

A simple reflection-pair optical tachometer head for my CD structural integrity tests.

14th December 2002

New Capacitors!

Some eBay wins pay off and my first serious Marx Generator is born.

Parent article: Marx Generator.

8th December 2002

Second Try

The Proof-of-Concept unit gets an extension.

Parent article: Marx Generator.

16th November 2002

Simple Electrometer

An ultra-simple, very sensitive electrometer.

10th November 2002

Electrostatic Motor

My small implementation of Bill Beaty's soda bottle electrostatic motor.

10th November 2002

High Voltage Probes

I've been working with high voltage quite a lot lately, so I decided to make myself some basic test equipment. Starting with a 1000:1 DC probe.

Contains 2 sub-articles.

3 comments.

10th November 2002

Bill Meara N2CQR writes

My first meeting with Bill of SolderSmoke fame.

Parent article: Trivial Electric Motor.

3rd November 2002

Marx Generator

Marx generator evolution, through many prototypes.

Contains 8 sub-articles.

3rd November 2002

Phone Tap

A simple interface for picking up the audio on a phone line.

3rd November 2002

Projectile Motion Pictures

Fooling around with a strobe light in the dark with long exposures.

3rd November 2002

First Proof-of-Concept Unit

The first Marx Generator I built.

Parent article: Marx Generator.

27th October 2002

Van de Graaff Generator

My small, and quite ugly, prototype built using house hold materials.

4 comments.

26th October 2002

Flogging a Flyback

Various fooling around with a old TV flyback transformer.

5 comments.

21st October 2002

Almost a Tesla Coil

Fooling around with a self-resonant long solenoid and modest RF power.

1 comment.

20th October 2002

A new MW loop

Parent article: Small Tuned Loop AM Broadcast Antenna.

5 comments.

19th October 2002

SM0VPO 500mW Linear Amplifier

My implementation of SM0VPO's cute little QRP linear amplifier.

2 comments.

17th October 2002

Trivial Electric Motor

A simple demonstration DC motor you can build in 10 minutes with your children.

Contains 1 sub-article.

2 comments.

23rd June 2002

SQLGraph

A simple SQL relationship graph generator.

7th March 2002

VHF Super-Regenerative Receiver

A prototype implementation of the Charles Kitchin N1TEV super-regenerative receiver featured in the ARRL handbook.

4 comments.

25th November 2001

FM Broadcast Band Transmitter

Harking back to my old days as a FM broadcast pirate, I whipped up this very simple 500mW transmitter.

4 comments.

25th November 2001

Small Tuned Loop AM Broadcast Antenna

A simple tuned-loop I threw together for DFing a local noise source that has been effecting my father's nightly listening to 2BL 702 kHz.

Contains 1 sub-article.

3 comments.

18th November 2001

Small 80m direct conversion RX

Small, peppermint tin sized, 80m receiver. Borrows the elegant WA6OTP PTO VFO.

10 comments.

11th November 2001

HF TRX with PTO based VFO

A small experimental HF rig based on a Permeability Tuned Oscillator for the VFO. Currently on 20m, but the plan is to move it to 80m once debugged.

3 comments.

27th October 2001

UHF Log-Periodic Array

A classic 6dBi LPA design for the Australian UHF TV broadcast bands IV and V. Initial tests indicated excellent pattern performance with ultra deep nulls.

Contains 2 sub-articles.

6 comments.

24th September 2001

Yet Another Comb Generator

A simple 14.91 MHz comb generator that I built for testing a S-Band dish.

3 comments.

24th September 2001

Simple AF Amplifier

My bench amplifier that I use for listening to small AF signals.

1 comment.

31st August 2001

Parts Cabinet

How I built my parts cabinet for all my electronic components.

Contains 1 sub-article.

2 comments.

27th August 2001

Quick Comb Generator

A quick hack to produce VHF/UHF and above test signals with ease.

2 comments.

27th August 2001

Tube Regenerative Receiver

A simple tube/solid-state hybrid regenerative receiver for the AM broadcast band.

5 comments.

3rd April 2000

EA Mag Pocket Sampler

A Linux driver for the Electronics Australia August 1996 Pocket Sampler project.

25th March 2000

My Pirate Radio Station

2HoT FM, my pirate radio station in high school.

9 comments.

24th March 2000

IR Remote Control Modem

My simple IR modem to let my computer talk to various consumer devices.

1 comment.