27th November 2011
I finally build Charles Wenzel's Curious C-Beeper capacitance probing tool.
10th July 2011
BPW34 photodiode based gamma radiation detector.
19th March 2011
A simple direct-conversion receiver for the Homebrew Group challenge this year.
28th February 2011
Some video from the 2011 CCARC Field Day at Wyong.
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.
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.
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.
14th November 2010
A relatively simple 11 transistor FM broadcast receiver using pulse-integration discrimination.
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.
12th May 2010
More compatible receivers and a few circuits related to the system.
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.
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.
23rd December 2009
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
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.
2nd June 2009
Some photos from the June 2009 ARNSW Homebrew Group Meeting.
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.
28th April 2009
I lash up an old Geiger tube and monitor the background radiation in the shack for a while.
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.
24th February 2009
I finally sit down and calibrate the front-panel controls of the QRSS beacon.
Parent article: 30 Metre QRSS Beacon.
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.
29th January 2009
A small variometer-style variable inductor as a prototype study of an interpolating inductor for an antenna matching unit.
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.
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.
20th August 2008
Some recent erudition from experiments on the 30 metre antennas.
16th August 2008
I complete and box-up the QRSS beacon, and experiment with a vertical antenna.
Parent article: 30 Metre QRSS Beacon.
10th August 2008
I get a basic QRSS beacon going on 30 metres.
Contains 3 sub-articles.
2nd August 2008
My slightly revamped return-loss bridge and using it for various measurements.
13th July 2008
I finally rig up a vertical antenna for my 80 metre CW beacon.
Parent article: 80 Metre CW Beacon.
29th June 2008
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.
21st June 2008
A simple 1.5 Watt Morse beacon for 80 Metres.
Contains 3 sub-articles.
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.
27th April 2008
More progress on the PSK-31 beacon.
Parent article: PSK-31 Beacon Mark 1.
20th April 2008
Prototype PSK-31 Beacon Keyer.
Contains 1 sub-article.
19th April 2008
Simple parallel port programmer for the Atmel ATtiny13 (and similar ATtiny AVR range) chips.
Contains 2 sub-articles.
18th April 2008
Better circuit diagram drawing for the super-regen tone dipper.
Parent article: Super-Regenerative Tone Dipper.
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.
8th March 2008
A small transmitting loop antenna for 20 metres using a Aluminium bicycle wheel rim.
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.
4th February 2008
I add a front-end and a box to the 30 Metre Autodyne Receiver
Parent article: 30 Metre Autodyne Receiver.
27th January 2008
An interesting and quite useful autodyne receiver that phase locks the remote RF signal.
Contains 1 sub-article.
18th December 2007
I put the regen-o-reflexive receiver on 31 metres and put it in a box.
Parent article: Regenenerative-Reflexive Receiver.
4th November 2007
An interesting detector idea from PA2OHH.
Contains 1 sub-article.
22nd September 2007
A super-regenerative dip meter that is extremely sensitive and easy to use.
Contains 1 sub-article.
16th September 2007
A simple dip meter using an audio tone as the read-out mechanism instead of a moving coil meter.
16th September 2007
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
A simple 50 Ohm power meter adapter for a multimeter. (Also talks about my diode probe.)
8th September 2007
A simple minimum-component super-regenerative receiver for the FM broadcast band.
17th July 2007
A regenerative receiver based on an emitter-coupled oscillator topology of elegant simplicity but fairly average performance.
9th June 2007
My experiments with JFET biasing lead to a simple 455 kHz IF module.
2nd June 2007
A quickie hack that actually worked pretty well.
26th May 2007
A twinlead j-pole design for 2 metres gives rise to measurements of velocity factor for VK-available twinlead.
26th May 2007
A very simple 2 metre AM transceiver from Roger Lapthorn G3XBM.
28th April 2007
Simple variable resistance and capacitance jigs for the bench.
15th April 2007
An 80 metre super-heterodyne SSB receiver built using BC556 devices only.
24th March 2007
A fairly small MK484 based receiver for the AM broadcast band.
11th March 2007
My cute little EFHW tuner with in-built VSWR bridge.
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".
25th February 2007
I put the 4 Watt exciter in an Aluminium box.
Parent article: "2007 80m Homebrew Challenge".
24th February 2007
IRF510s arrive and I build a TX power-chain.
Parent article: "2007 80m Homebrew Challenge".
18th February 2007
I go to the CCARC field day and think about different RX topologies.
Parent article: "2007 80m Homebrew Challenge".
17th February 2007
I get the TX talking to the RX and true First-Light for the Receiver.
Parent article: "2007 80m Homebrew Challenge".
7th February 2007
I start building the RX side of things.
Parent article: "2007 80m Homebrew Challenge".
5th February 2007
I build the AM exciter, including crystal oscillator and speech amp.
Parent article: "2007 80m Homebrew Challenge".
31st January 2007
I decide on low-level AM modulation, design and breadboard an AM modulator.
Parent article: "2007 80m Homebrew Challenge".
28th January 2007
Clarification on the Challenge requirements means a completely different approach.
Parent article: "2007 80m Homebrew Challenge".
24th January 2007
I complete a 1 Watt DSB transmitter lash-up.
Parent article: "2007 80m Homebrew Challenge".
22nd January 2007
My study of the VE7GC "Wee Willy" 80 metre DSB transmitter power amplifier.
21st January 2007
A basic 50 Ohm switched attenuator.
20th January 2007
Another rotating multi-draw cabinet.
Parent article: Parts Cabinet.
14th January 2007
My experiments with the VK2ZOI Flower-Pot antenna for 2 metres.
13th January 2007
A very easy to get going VHF impedance bridge for antenna work.
13th January 2007
My work towards the ARNSW Homebrew Group's "2007 80m Homebrew Challenge" transmitter project.
Contains 11 sub-articles.
13th January 2007
I first read about the challenge on the ARNSW website.
Parent article: "2007 80m Homebrew Challenge".
7th January 2007
A simple direct conversion receiver for 80 metres using a ceramic resonator VXO.
18th November 2006
My go at making a JF1OZL-style spectrum analyser for 40 metres.
11th November 2006
A simple filter-based SSB exciter. Still work in progress, but will some day become an SSB transceiver.
11th November 2006
A quick folded dipole antenna for 3 metres.
4th November 2006
An extremely useful RF sweep generator.
3rd September 2006
My implementation of Dick Cappels' simple RF Inductance Meter.
2nd September 2006
My copy of VK5BR's sweeper detector.
6th August 2006
A simple 3-transistor regenerative receiver from the MW broadcast band.
10th May 2003
Fred Kennedy noticed the circuit diagram might be wrong.
Parent article: High Voltage Probes.
10th May 2003
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.
14th April 2003
Parent article: UHF Log-Periodic Array.
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.
4th April 2003
Going LF/VLF/ULF with a large multi-turn loop.
20th March 2003
Richard Solis asked me to post the circuit diagram.
Parent article: High Voltage Probes.
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.
9th February 2003
Built to show ceramic caps are generally OK for Marx service.
Parent article: Marx Generator.
28th January 2003
Characterizing the testing supply, and some more thoughts towards building "the big one" some day.
Parent article: Marx Generator.
27th January 2003
More new capacitors lead to a multi-Joule device.
Parent article: Marx Generator.
14th January 2003
An attempt at a choke charging Marx generator.
Parent article: Marx Generator.
5th January 2003
Two new prototypes for the New Year.
Parent article: Marx Generator.
22nd December 2002
Demodulation of microwave radiation using a Neon plasma.
14th December 2002
A simple reflection-pair optical tachometer head for my CD structural integrity tests.
14th December 2002
Some eBay wins pay off and my first serious Marx Generator is born.
Parent article: Marx Generator.
8th December 2002
The Proof-of-Concept unit gets an extension.
Parent article: Marx Generator.
16th November 2002
An ultra-simple, very sensitive electrometer.
10th November 2002
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.
3rd November 2002
Marx generator evolution, through many prototypes.
Contains 8 sub-articles.
3rd November 2002
A simple interface for picking up the audio on a phone line.
3rd November 2002
The first Marx Generator I built.
Parent article: Marx Generator.
27th October 2002
My small, and quite ugly, prototype built using house hold materials.
19th October 2002
My implementation of SM0VPO's cute little QRP linear amplifier.
17th October 2002
A simple demonstration DC motor you can build in 10 minutes with your children.
Contains 1 sub-article.
7th March 2002
A prototype implementation of the Charles Kitchin N1TEV super-regenerative receiver featured in the ARRL handbook.
25th November 2001
Harking back to my old days as a FM broadcast pirate, I whipped up this very simple 500mW transmitter.
25th November 2001
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.
18th November 2001
Small, peppermint tin sized, 80m receiver. Borrows the elegant WA6OTP PTO VFO.
11th November 2001
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.
27th October 2001
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.
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.
27th August 2001
A quick hack to produce VHF/UHF and above test signals with ease.
27th August 2001
A simple tube/solid-state hybrid regenerative receiver for the AM broadcast band.
25th March 2000
2HoT FM, my pirate radio station in high school.