Technical Projects and Presentations Page

If you have a technical project or idea to share, email the Webmaster with the write-up and any schematics, photos, etc.

Technical Projects

Sound Card Modems  by Dale Chidester NJ7C - presened on 11/2/2015
How they work, and how to build one for substantially less money than a commercial interface. 

Winlink and RMS Express EMCOMM Capabilities  by Bill Hickey AB7AA - presented on 10/5/2015
What WINLINK and RMS Express are, and how they can support Emergency Communications. 

Portable VHF Antenna System  by Bruce Johnson N7NYG
A VHF antenna system suitable for portable operations where an HT or mobile whip isn't enough. 

Understanding Antennas For The Non-Technical Ham
A Web Book By Jim Abercrombie, N4JA (Jim Abercrombie
(Thanks to Chip KE4UQG.)

The KC0LL Repeater Net, by David Branson KC0LL. Click here for the PDF version.
The Mt Lemmon UHF 444.975 (RPT Rx) / 449.975 (RPT Tx) 100.0 PL repeater can be linked to Mule Mt. (Bisbee) by using 107.2 tone on each end.

Antenna Pre-amp Power Sequencer Protection Circuit, By John, KD7DO

How to build a G5RV 3.5MHz - 28MHz antenna, by Charles, K4AFN (this is a 2MB PDF file)

Constructing inexpensive sound card interfaces,
by Charles, K4AFN (PDF)
These three circuits interface your transceiver audio in, audio out, and press-to-talk with your computer.
"I have built several of these and they work just fine. I have used them on HF tube tranceivers (HW-101), Yaseu and Icom HF rigs, VHF mobiles and HTs."

Portable Dual Band Antenna, by Charles, K4AFN (1.2MB PDF file)

Constructing a portable station using a HVOB (Highly Versatile Orange Box), by Charles, K4AFN and Bob, N7INK (1.8MB PDF file) updated 8/5/2010

HVOB station There are ideas, plans, suggestions and photos of HVOBs constructed by K4AFN and N7INK and also some web references for other examples. The unique feature of this project is that the radios and equipment are attached to a rack that can be removed from the case to access wiring connections on the rear of the rack or for operation outside of the case on a bench or table. The case is water tite and sturdy enough to sit on. The box is deep enough to provide ample room in the back for accessories and cables. There is also room for your manuals, charts, spare parts, and antenna components.

Technical Presentations at CARA Meetings

NJ7C: WINLINK 2000 Global Radio Email System at the Mar 5, 2012 CARA meeting.

Ev Wittig WB7VNF's "Dream Station" presentation at the Oct 3, 2011 CARA meeting.

NJ7C: Digital Sound Card Interfaces on the Cheap! at the Feb 7, 2011 CARA meeting

Thanks to
Clarence Peckham NT7V for his excellent
Software Defined Radio (SDR)
presentation at the Feb 1, 2010 CARA meeting.
Click here for the PDF version. Click here for more info.

WB6OTS: Contesting and Why It's Important at the Oct 5, 2009 CARA meeting

WB6OTS' National Traffic System (NTS) presentation at the Oct 6, 2008 CARA meeting

K7WIN's Satellite Presentation at the Feb 4, 2008 CARA meeting

Page updated 06 Mar 2012