Presented at the Ontario VHF Association "Do" 2009
Antenna Heights for 6m Sporadic E
Presented at the Central States VHF Society Conference, Mississauga, ON, 2004
222 MHz Yagis with Direct 50 Ohm Feed
Presented at the Ontario VHF Association "Do" 2008
Introduction to Microwave Ham Radio
Presented (mostly in conjunction with VE3EZP (SK) or VE3RKS) to several southern Ontario amateur radio clubs, 2005-2008
20 Plus Years of Ontario SHF Activity
Presented (with VE3RKS) at a Rochester (New York) VHF Group meeting in 2009
A simple antenna for 2304 MHz
Presented (with VE3OIK) at the Ontario VHF Association "Do" 2003
Also in the Proceeedings of the 38th Conference of the Central States VHF Society, 2004
Sequencer for use with the Elecraft K2 and a VHF transverter and power amplifier
The K2 is a nice IF radio, but there is no way to prevent it from transmitting in CW when the key is pressed. With a standard sequencer this means that RF drive may be present at the transverter input while the antenna relay is switching, which could damage the transverter. This sequencer interrupts the RF input to the transverter to prevent this problem.
28 MHz Transmit IF Filter for K2
Another challenge when using the K2 with transverters is the sensitivity of the transmit IF output of the K60XV to RF. This filter solves most of the problems. Here are some discussions on the Elecraft reflector on this subject: RFI Susceptibility Unadvertised feature Solution found EMC Issues
2 MHz Crystal Calibrator for VHF
Schematic only !
How to build it....
Receiver and Transmitter Schematics for Laser Communications
Schematics only - for tone modulated CW gear using a cheap laser pointer
12-LED Optical Transmitter Schematic
Easier to aim than a laser pointer !
New photodiode preamp design (2011) - JPEG file
An experimental design....still under evaluation
Simple Detector for RF Power Measurement
Using 1N5711 diode
Notes on VXO QRP Transmitter Design
Includes details of a 20m 1 watt design - old stuff with dubious copy quality
Table of 50 ohm pi attenuator designs using standard value resistors
1-50 dB attenuation, VSWR < 1.20, 10% resistors
Power Dissipation in Ferrite Bead Baluns at VHF (Draft 3 - Revised Dec 2011 - new 6m example)
My initial thinking on this subject. Feedback and critiques, as well as real life examples of what works and what doesn't, are welcome.
A Junkbox Switching Power Supply for 28 Volt Relays
Not very elegant or efficient, but uses common parts and it works
A Simple Microwave Noise Source
Uncalibrated, but still a useful and cheap piece of test equipment, good up to at least 10 GHz
Approximate Methods for Calculating Zo and V.F. of "Wire Microstrip"
Approximate impedance and velocity factor for a wire on the surface of a PC board
An Iambic Morse Keyer with No Clock
An unusual keyer design (from the days before I had a computer to document stuff with)
A design for a 100 watt class dummy load for HF
Uses lots of ordinary 2 watt resistors
A Fine Pointing Mechanism for an Optical Transceiver
Provides slow motion rotation over a few degrees in azimuth and elevation
more to come.....
