|
|
 |
|
 |
Go to the discussion about audio-frequency allpass networks |
 |
This is the paper on AM demodulators, with an emphasis on the diode type, pointing out the deficiencies commonly encountered. |
 |
This paper discusses pulse-width modulation with an emphasis on the post-switch lowpass filter. |
 |
This paper outlines the steps taken to design an unusually-effective "speech amplifier" for ham radio use. |
 |
Photo documentary of the rebuild of a Collins 180S-1 tuning unit |
 |
|
 |
Download the active bandpass filter designer. This program uses the multiple-feedback scheme; it offers analysis in addition to design and tuning of the various components. And, most uncommon in such programs, it includes correction for the real-world opamp GBW. Writes ready-to-run LTspice schematics. |
 |
Download the active lowpass filter designer. This program uses the Salen-Key scheme; it offers analysis in addition to design and tuning of the various components. |
 |
Download a program which can be used to quickly design the RF lowpass filter used in the BITX (or other transceivers that have 50-ohm filters). |
 |
Download the program which can assist in setting the component values for the BITX transceiver VFO. |
 |
Download a PDF (320 KB) file which illustrates how the BITX VFO tuning program functions. |
 |
a specialized filter design and analysis program designed for the serious radio amateur to expedite the design of optimized amateur-band output transmitter lowpass filters. |
 |
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 Windows® program allows you to manipulate network components as if you were doing it on a printed Smith Chart but is designed to be much more intuitive and user-friendly. Inputs are the operating frequency, the R and jX value for the load and the network components, up to eight. Various network topologies may be entered and tuned. Outputs are the usual collection of Smith Charts. This program is under development and suggestions are welcome. |
 |
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 SPICE and LTspice files. |
 |
Download a program to design stepped volume controls. The program also analyzes the resultant design. |
