Jim Ahlstrom

PC board image

Personal

I live at 221 Pleasant Plains Road, Stirling, New Jersey 07980 USA with my wife Susan. We have two children, Jennifer and Michael. My main sports are birding and skiing. I also enjoy cooking. I am an exercise junkie, and work out at the gym nearly every day. I retired from Interet Corporation on January 1, 2012. You can email to this address or call me at home at 908-580-1319.


Hermes Lite SDR

I am active in the Hermes Lite project. Steve Haynal, KF7O, and a group of interested amateur radio operators are working to develop a direct sampling Software Defined Radio. The clock is 76.8 million samples per second, and the bit depth is 14 bits for both transmit and receive. The radio is on a 10cm x 10cm printed circuit board and features both low power and 5 watt RF output. The connection to the controlling PC is via gigabit Ethernet. Low cost is a primary objective, and the project is based on an AD9866 digital modem chip. This is a great project that will bring low cost SDR to everyone.

Electronics and Software

I first taught myself electronics as a teenager. I used tubes (valves), and I remember how excited I was to get my first transistor, a CK722. Since than, tubes were replaced by transistors, and transistors by integrated circuits. Opamps barely worked at audio, but now they can do 100 MHz. Electronics changes, and I lost track of how many times I relearned it.

I am an amateur at electronics, but a professional computer programmer. My main computer languages are Python, C and Fortran (yes, Fortran 77). I can manage some Verilog, Atmel AVR assembly language, C++ and several Unix mini-languages. I am a big fan of the Python language, please check it out. Python is an easy to use programming language with advanced features like classes and structured exception handling. It is mature, powerful, practical and free. It runs on Windows, Linux, Unix, Macintosh and other systems.

Ham Radio Projects

I got my first Amateur Radio license as a teenager. Amateur radio operators are licensed in the U.S. by the FCC to operate radio transmitters. We "hams" use our stations to chat with other hams around the country and around the world. My teenage license expired when I got busy with college. I got re-licensed later, but that license expired when I was raising my kids. In 2006 I got my most recent license, and I got my old call back, N2ADR.

I am interested in digital radio and Software Defined Radio (SDR). There is a lot of activity in this area. My home station is a homebrew SDR transmitter and receiver. The hardware is my own design, and the software runs on a Windows or Linux PC. It is the only transceiver I have. The only commercial radios I own are an AOR AR8600 receiver and a handheld Yaesu VX-6. The hardware design files and the software for my transceiver are available on this site. Use the navigation links above.