Site of Lloyd Butler VK5BR

Many articles by Lloyd Butler VK5BR have been published in journals, including Amateur Radio and OTN since the 1980's.
The site has been set up to display some of the material published.

Test Measurements and Test Gear
     Measurement of Distortion
     Waveform and Spectrum Analysis
     Intermodulation Performance and Measurement
     FM Deviation Meter
     RF Inductance Meter
     An LF Antenna Bridge
     An Experimental Q Meter
     Heterodyne Sweep Generator
     Transmission Line Balance Test Meter

Noise Cancelling
Unwanted Coupling of Stray Signal or Noise

Introduction to the Superhet Receiver

Mixer Theory

Application of Switched Capacitor Audio/Speech Filters
     An Adjustable audio Filter System for the Receiver
     Combined Speech LP and CW Filter in one I/C
     A Wideband Variable Audio Oscillator uses a Switched Capacitor Filter

Negative Resistance Theory
     Lambda Negative Resistance Dip Meter

Single Coil Z Match
     Toroidal Core Single Coil Z Match
     Single Coil Z Match for 1.8 MHz
     Single Coil Z Match Load Curves
     Single Coil Z Match for Higher Power
     OTN article on Single Coil Z Match development
Efficiency of the Z Match
Output Balance on the Z Match
Matching Load Range - Drop-Out for Certain Capacitive Loads

Small Magnetic Transmitting Loop Antennas
     Loop for 14MHz and 21MHz
     Loop for 2 meters

Small Receiving Loop Antennas and Interfaces
     VLF-LF and the Loop Aerial
     An Active Loop Converter for the LF Bands
     The Active Loop Converter at VLF
     Antenna Noise and Signal Cancelling at LF
     Noise Blanking for High Q LF Loop Antenna
     Receiving Loop Aerials for 1.8 MHz
     VLF Ferrite Core Loop Antenna

VLF-LF Receiver with Resistance Tuning
Simple VLF-LF Regenerative Receiver

Transmission Lines & Antenna Matching
     Transmission Lines - Measurement of their Characteristics
     Measurements on Balanced Lines
     The Merits of Open Wire Lines
     Loading up on 1.8MHz Using the L Match

     An Approach to Antenna Matching & Tuning (L Match)
     Top Loading by Reverse Feed An interesting idea to get high current running      
      at the top or end of an antenna wire

     Transmission Line Balance Test Meter
          Modification to meter to measure relativity of Longitudinal to Differential Current

Amplifiers and Amplifier Theory
     The Transistor as a Voltage Amplifier
     RF Power Amplifiers - Tank Circuits & Output Coupling
     MOSFET Linear RF amp for HF
     Output Impedance - Source Impedance - Load Impedance
     Amplifier Noise
     Unbuffered CMOS Inverters as Amplifiers - One I/C package TRF Receiver

LF Transmitting Equipment
     LF SSB Modulator using Phasing Technique
     HF to LF Transmit Converter
     LF Power Amplifier
     LF Antenna Loading and Tuning
     Measurement of LF Antenna Resistance and Reactance

Power Supplies
     Design of Regulated Power Supplies using Series Regulator Packages
     Test Load for 20amp DC Power Supply
     Zener Diodes - Some Interesting Characteristics
     Radio and the early Direct Current (DC) Mains in South Australia

Transmission Systems
     Modulation Systems and Modes of Transmission
     Narrow Band VoiceTransmission
    An Introduction to Fibre Optics and Fibre Optics Communications
     Satellites of the World & its Facilities

The Ladder Filter Revived

Transmission of EM waves under water

Undersea Cables of the World

Electrical Safety - On the Secondary Side
The Dangers of Electromagnetic Fields

Power Generation & Distribution
      Repowering North of South Australia
      Power from the Sea
      Base Power Systems & interaction with Renewable Sources
      Some Energy Plans for South Australia
      Wairakei Geothermai Power Station, New Zealand.

Some Historic Information

History of Amplitude Modulation Broadcasting in South Australia

Early Background of our Telegraph Codes

Some Early Tele-Communications History including the PMG
      The Transmission Section of the PMG 's Dept. in Adelaide
      South to North Telegraph Line Australia
      First Undersea Telegraph to the World
      The early Phonopore, telephone over telegraph
      Undersea Cable across Bass Strait
      Cape Otway - Early history of Undersea Telegraph & Wartime Radar
      Bi-Directional Amplification in Communication Lines
      The PMG Adult Technician-in-Training Scheme

Department of Civil Aviation (DCA)
Some early radio history of the DCA in South Australia
A History of Parafield Airport & its Facilities

Some history of the AR7 Receiver in the Department of Civil Aviation
History of Leigh Creek & its earlyAirport Radio Installations in DCA

Early Mobile Radio at the Woomera Range

WRE Type 2 HF Transceiver - Instruction Handbook
      WRE Type 2 HF Transceiver - Chassis Layouts
      WRE Type 2 HF Transceiver - Circuit Diagrams

Before Valve Amplification - Wireless Communication of an Early Era.

Introduction of Talking Pictures

The Early Medical Induction Coil

The Eiffel Tower and its early Radio use

The old Narrow Gauge Railway Line and the Ghan

History of Amateur Operators Certificate in Australia

Lloyd has been the Historian for the Adelaide Hills Amateur Radio Society (AHARS) for a number of years - Here are some articles on the AHARS Internet site concerning history of the Club and its early predecessor, the Blackwood Radio Club.

History of the Adelaide Hills Amateur Radio Society
     The early Blackwood Radio Club
     Origins of the Adelaide Hills Amateur Radio Society
     The Lower Murray Radio Club

The Lower Murray Club, commencing in 1976 in the town of Murray Bridge, is now part of the Adelaide Hills Club. However the amateur radio history in Murray Bridge goes back to 1924. Click here to engage the Murray Bridge Amateur Radio Story.

Some early history at Murray Bridge:
     Train Wreck at Murray Bridge Station
     Forced Landing of Guinea Airways plane at Murray Bridge

The Wireless Institute of Australia (WIA) has been a representative of Amateur Radio in Australia since 1910. (It is the oldest Amateur Radio Society in the World.)
Listed here is an early history of the South Australian Division of WIA from 1919 to 1980 written by Marlene Austin VK5QO/VK3EQO,, originally published in AR in 1985. and later assembled in digital form by Lloyd.

Also listed here is additional history of the South Australian Division of WIA from 1980 to 2004 and prepared in 2013 by Lloyd Butler VK5BR,

Other References