Get the paper about allpass networks used to improve speech amplifiers.
860 kb PDF; updated 4 January 2017.
Download the tutorial about electrical filters. This is the talk given to the Oak Ridge Tennessee Amateur Radio Club
about filters. Starts with the basics.
This is the paper on AM demodulators, with an emphasis on the diode type, pointing out the deficiencies
commonly encountered. Seriously upgraded 6 December 2012 with considerable new material and graphics. This is a 3 MB PDF
This paper (PDF) discusses pulse-width modulation with an emphasis on the post-switch lowpass filter.
This Windows® program allows you to print both great-circle (polar) and rectangular projections of maps of the
world. Polar is as seen from a specified home location. Also shows the azimuth and distance to a specified target. Easy
to enter new home or target locations. Shows/uses Maidenhead strings.
Get the program which allows you to enter the values of an ordinary matching/network adjusted to match a reactive load to
a specified system impedance. It then returns the load's R and jX values. All eight of the usual two- and three-element
topologies are accommodated.
This program allows you to see the values of R and jX looking into the base of a vertical antenna over an ideal ground.
Although the program is based on that ideal ground and a cylindrical metallic tower, it has proven very useful in the
real world. Inputs are the tower height and diameter and the analysis frequency range. Output is a plot of R, jX and Z as
a function of frequency. Log or linear sweep, output to a printer as well as screen.
Download the tube curves program based on the Koren parameters. Writes LTspice files.
Download the program to design stepped volume controls. The program also analyzes the resultant design.