Updated 7/03/2017

Projects Page

This page hosts my project write-ups and other miscellaneous documents. The tone of these documents range from conversational to full-up technical (and everything in-between). Note that the scope of the projects presented is not limited to repeaters or Ham radio (tho that is the typical subject matter juris diction).

Mobile Radio Control System

This is the culmination of several decades of thought and effort directed toward a radio control interface that is purpose built to allow several radio platforms to be operated using a unified user interface. This section will see additional material added as the project nears completion (which will hopefully happen in 2017).


"Iambic Key Paddles" describes the construction of a set of iambic keyer paddles for my mobile installation.
"ICOM OPC-172 Clone" describes the construction of an optical cable clone for my mobile IC-901/EX-766 installation.

Orion-I Microwave Synthesizer

"The Orion-I 35-4400 MHz PLL Synthesizer" describes the construction and use of a very versitile microwave synthesizer that can be built on a modest budget.

A 902 MHz, FM TX for the IC-901

This project produced a 902 MHz TX module to allow my IC-901 access to this band.

A Tracking Generator for the HP8566B

This write-up describes the design and construction of an indispensible add-on to this venerable spectrum analyzer.

Connecting the HP 5086-7023 YTO

"Connecting the HP 5086-7023 YTO" describes the circuit requirements for connecting an HP YIG-Tuned Oscillator for operation as a stand-alone unit.

68HC711 Programmer Interface

This project, "The KE0FF HC11 Programmer Interface" describes my side trip into the way-way-back so that I can have a useable programming tool for the HC11 projects that I support. This combination of hardware and software replaces the DOS PROG11 executables that no longer work on WinXP or above. It is a versitile interface with some scripting options that make me wish I had developed it 20 years ago. Better late than never, I suppose...

The Design Files for this project contain all of the source code and schematics. There are even gerber files for a PCB (that I never got the chance to fabricate).

As part of this effort, I dis-assembled the M68HCHC711D3 bootloader ROM. Motorola/Freescale provided this listing for nearly all of the HC11 variants. However, after an extensive search the 711D3 listing could not be found. It is very likely that no one will ever need this, but I have made the listing available just in case.

GPS Disciplined, 10MHz Timebase

My project, "The KE0FF 10MHz GPS Disciplined Oscillator" (preliminary release) describes my forray into the world of precision references.

PIN Diode T/R Switch for 6M

My paper, "A PIN Diode T/R Switch for 6M" describes my effort to build a self-contained, 100W PA for 6M using a PIN diode RF switch and a MastrII low-band VHF radio.

ICOM UX Module Diaries

I have embarked on a somewhat extensive writing project to detail my efforts to de-cipher the control protocols of the ICOM UX modules (used with the ICOM IC-900/901 transceivers):

"ICOM UX-R91 Broadcast Receive Mod" describes a modification to correct a design flaw in the UX-R91 receive module. The flaw produces a noticable white noise in the audio output of the IC-901 when receiving WBFM and WBAM broadcast stations.

Morse/Tone to .wav script

I recently spent a lot of time adapting a script by Gan Starling, KY8D, that converts text files to morse code .wav files. I added a tone generate function and used it to re-create "My Favorite Courtesy Tones". The new CT audio files can be found there and can be played directly from most browsers.

The script is in PERL and is available for download. You have to have the PERL interpreter installed, but this is free and painless. I use it mainly to create ringtones for my iphone, but it is great for code practice too. The script download includes an "instruction" document with tone examples and instructions on how to create a tone source file (a text file) that the ct.pl script can use to create a .wav file which can be played on your PC or exported to your favorite music player. Go to www.perl.org to get the PERL interpreter. Cool stuff.

UPDATE: October 12, 2013

Updated the ZIP archive with improved instructions and added the two PERL modules that are required for the ct.pl script to work properly (so you don't have to scour the web to find them yourself). The improved instruction file includes more detailed PERL installation guidance (Windows-centric) and more detail on the script syntax used to write the source files that the ct.pl script uses to generate tones and CW.

Mazda 6 Stereo interface

I spent some time working on an ipod interface to my Mazda 6 stereo a while back. It emulates a Mazda tape deck and allows the factory stereo controls to manipulate some of the ipod remote functions. It also provides a direct ipod audio link to the stereo. I wrote a blog-like account of the reverse-engineering and design process. You can find the detailed design data here. More cool stuff.

Motorola APPNOTES that I've Authored

AN1771 - Precision Sine-Wave Tone Synthesis Using 8-Bit MCUs

AN1753 - Implementing a FLASH Memory System in an MC68HC711E9 Design


On the Bench...

These are some of the projects that I'm trying to get to in the near future: