Site Search

Copying

The articles on this site may be updated from time to time and copied articles become stale. Whilst you might think that converting an article to PDF and publishing it is pretty cool, you are doing your readers a disservice by offering them up stale articles. Besides that, it is a breach of copyright law to make unauthorised copies. Please don't copy content from this site.

New

Title	Date (DD/MM/YY)	Categories
137.7kHz QRSS on one chip (revised 3/2/12)	03/02/12	Transmitters
Improving weak signal identification of FSK beacons	03/02/12	Equipment
Simple Morse beacon keyer	03/02/12	Equipment
Effective Radiated Power (ERP)	17/01/12	Antennas
Jaycar MI5104 inverter	16/01/12	Equipment
DTR / RTS interface unit	15/01/12	Equipment
Insertion Loss vs Transmission Loss	15/01/12	Transmission Lines
Adjusting a loaded HF vertical	13/01/12	Antennas
PllLdr application - AD9850/51 300Bd FSK	08/01/12	Equipment
ZL1AN's transmission line challenge	09/01/12	Transmission Lines
Setup of an FM AFSK transmitter	06/01/12	Transmitters
APRS AFSK on VHF	04/01/12	Transmitters
PllLdr application - AD9850	28/12/11	Equipment
Is the 133' centre fed multiband dipole a no-brainer	26/12/11	Antennas
Calculate Vpk and Irms for given power at complex load	26/12/11	Software
N0XAS ID-O-Matic - VK1OD implementation	09/12/11	Equipment
A medium priced generator set from eBay	07/12/11	Equipment
An experimental CPLD based PLL (revised)	03/12/11	Equipment
MCU to load PLL configuration registers	02/12/11	Equipment
Comment on W5DXP's 2011 coil measurement experiment	18/11/11	Antennas
Exploitation of NEC's GM card	14/11/11	Antennas
T Match efficiency estimator	12/11/11	Software
Ambient noise survey, Hackett ACT on 40m, 06/03/2009	12/11/11	Software
PA0KLT Si570 Synthesiser - VK1OD implementation	12/11/11	Equipment
Matching a 5/8λ vertical	03/11/11	Antennas
In pursuit of dipole resonance with an MFJ259B revised	02/11/11	Antennas
Spotless days around solar cycle transition Nov11	02/11/11	Propagation
Is Zs of a HF ham tx typically 50+j0?	20/06/10	Transmitters
A test of Zs on an IC7000	01/08/10	Transmitters
Link coupling transformation ratio (expanded 29/10/11)	29/10/11	Transmitters
Learning models or a poor workman always blames his tools	28/10/11	Antennas
Bootstrap coax traps for antennas (expanded 10/11)	26/10/11	Antennas
Differential flux leakage in a Guanella 1:1 balun	26/10/11	Baluns
ATLLC Examples	10/10/11	Software
RF Arbitrary Transmission Line Loss Calculator	09/10/11	Software
Estimating parameters of two wire transmission lines	07/10/11	Transmission Lines
Noise bridge measurement case study - Bowral dipole	07/10/11	Measurement
Noise bridge measurement case study - shortened vertical monopole matching	06/10/11	Measurement
Filament Management in Amateur Radio applications	28/09/11	Transmitters
Does twisting a two wire open line reduce radiation	23/09/11	Transmission Lines
Can a balun alter the tuning of an antenna system	13/09/11	Baluns
Spoiling Class B	12/09/11	Transmitters
440Hz (A4, A440) reference oscillator	11/09/11	Hardware
Return Loss	06/09/11	Transmission Lines
Misunderstanding VSWR misleads	03/09/11	Transmission Lines
G4CQM 50Ω coaxial dipole	02/09/11	Antennas
Spotless days around solar cycle transition Sep11	02/09/11	Propagation
Calculate braid coverage	31/08/11	Software
137.7kHz oscillator	28/08/11	Transmitters
1kHz reference oscillator	27/08/11	Hardware
Dipole loaded vertical coax feed line	13/08/11	Antennas
Noise Figure Meter (NFM) update - V1.11.0	10/08/11	Software
Portable generator sets and RCD protection for Amateur Radio field stations	07/08/11	Hardware
QRP2000 Synthesiser	05/08/11	Hardware
DHL shipment performance	05/08/11	Miscellaneous
Avoiding flashover in baluns and ATUs	05/07/11	Transmission Lines
RX1 Noise Bridge improvement	22/06/11	Measurement
Codan 7004 - WSPR 40m	20/06/11	Receivers
Designing with the GI7BT	14/06/11	Transmitters
Convert Vpk-Vrms-dBV-dBu-mW-dBm	11/06/11	Software
Antenna Effective Aperture	05/06/11	Antennas
Measuring RF impedance by the three voltmeter method	04/06/11	Measurement
Measuring common mode current	30/05/11	Measurement
Pi coupling a single ended valve RF Power Amplifier	28/05/11	Transmitters
Calculate RF amplifier pi coupler	28/05/11	Software
Designing with the GS31B	23/05/11	Transmitters
Calculate initial load line of valve RF amplifier	22/05/11	Software
Bowral 7MHz dipole for local contacts (updated)	22/05/11	Antennas
Designing the operating point for a grounded grid Triode Class B RF amplifier	16/05/11	Transmitters
Using my Excel cubic spline interpolation functions	07/05/10	Measurement
A perspective on the popular 4:1 Ruthroff balun at the base of a ground mounted untuned multi-band vertical	06/05/11	Baluns
Comment on QEX article - "Coaxial Traps for Multiband Antennas, the True Equivalent Circuit"	02/05/11	Antennas
A review of the Aoyue 937+	17/04/11	Other
Electronic fluorescent light starters	15/04/11	Other
Heater Delay Timer	12/04/11	Hardware
DTR - PTT interface adapter	10/04/11	Transmitters
RX1 Noise Bridge - VK1OD build	08/04/11	Measurement
QRZ forums	04/04/11
ARRL Noise Bridge worked example reworked	03/04/11	Measurement
Generic noise bridge calculator	02/04/11	Software
RX1, RX2 Noise bridge calculator	02/04/11	Software
Definition: Current Balun, Voltage Balun	19/03/11	Baluns
Field Strength Calculator (FSC) update - V1.0.12	02/03/11	Software
Baluns in antenna systems	20/12/10	Baluns
Yaesu FL2100Z	25/11/10	Transmitters
Folded Half Wave Dipol e	24/10/10	Antennas
Half Folded Half Wave Dipole	20/10/10	Antennas
Tapping an air cored RF inductor	19/10/10	Transmitters
StationMaster on 40m	15/10/10	Antennas
Exploration of a design for an 80m vertical antenna - Part I	14/10/10	Antennas
Counterpoise - what does it mean?	10/10/10	Antennas
A simple explanation of the so called current forcing property of a quarter wave transmission line	06/10/10	Antennas

VK1OD News feed for recent new or significantly revised articles, VK1OD software feed for Software Updates alone.

Themes

Antennas	Baluns
Transmission Lines	Rigging
Propagation	Measurement
Transmitters	Receivers
Hardware	Software, Calculators
	Reference
Other	Site MAP

Some wisdom that shapes articles on this site

A quotation from Lord Kelvin: When you can measure what you are speaking about, and express it in numbers, you know something about it. But when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. It may be the beginning of knowledge but you have scarcely in your thoughts advanced to the state of science.

A quotation from Albert Einstein: It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience. Often paraphrased as Everything should be made as simple as possible, but no simpler.