Atlanticon 2007 ...

Presentation Overviews

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These six exciting presentations were delivered on Saturday at the Atlanticon QRP Forum.

 

QRP Remote Control -- by Joe Everhart, N2CX

Usually amateurs focus on person-to-person communications.  But another facet of ham radio is communications of another type – remote control.  Combining communications and digital techniques make remote control a fertile ground for homebrewers.  We all make use of a number of remote control applications daily without even thinking about it. This talk will discuss familiar examples, some basic techniques and lots of ideas for how we as amateurs and homebrewers can roll our own very simply.

QRP Computing ... Getting In Touch With Your Inner Geek -- Brian Riley, N1BQ

There should be little question in any ham’s mind that a computer is a useful tool, but yet many are held off from taking full advantage of it by what appears to be a steep learning curve. In 1992 a company called Parallax made a start on changing all that with the introduction of their BASIC Stamp. We will briefly look at the long voyage for this generic tool of many sizes and shapes. To many the idea of being able to program a small microcontroller is daunting. In order to debunk this air of invincibility, we will look at some basic circuits and related code snippets that serve as building blocks to ham-oriented projects. We'll also have some live demonstrations of projects using the building blocks of the PICAXE family of processors ... which also happens to be at the core of this year’s Atlanticon Project, the Rookey!

PSK31 RF Beacon Project -- Jim Everly, K8IKE

Over the years I have enjoyed building various kits offered by NJQRP and recently discovered that many of them were collecting dust on my “project completed” shelf. Also, over the past couple of years I have introduced the NJQRP PSK31 Audio Beacon project to a group of students in a digital communications class that I teach every Winter Quarter at the University of Cincinnati. After a couple of iterations of the project I noticed that student comments on the “project evaluation” form tended to centered around adding additional capabilities to the project. This project is a direct result of those student evaluations together with a contentious attempt on my part to utilize previously introduced NJQRP projects to develop a PSK31 RF Beacon concept. The project presented in this paper illustrates the integration of a 433.92 MHz wireless temperature sensor into a PSK31 modulated audio beacon transmitter. The temperature sensor is a Dallas Semiconductor DS18S20 integrated into standard "off-the -shelf" 433.92 MHz RF transmitter module that uses amplitude modulation. The transmission method known as "On-Off Keying (OOK)" transmits the temperature data by simply switching the carrier signal on and off. The RF data link serial receiver can be located up to 500 feet from the transmitter and interfaces to the PSK31 Audio Beacon via an RS-232 interface. The NJQRP Audio Beacon features PSK31 encoding and audio waveform generation using a single-chip SX-28 RISC microcontroller operating at 50 MHz. The beacon has a choice of three base carrier audio frequencies namely, 500 Hz, 1 kHz, and 2 kHz. The audio output from beacon feeds the transmit section of and 80 meter Warbler introduced by NJQRP several years ago. The Warbler power output is sequentially reduced by switching in-line a series of 3 dB attenuators until the output power reaches 0.5 watts. Each time the output power is reduced by 3 dB the local temperature is updated. The transmit data string consists of station identification, grid square location, return email address, local temperature in °F, and output power level. Now, thanks to the efforts of NJQRP members, I have a project that is more robust and offers Electrical and Computer engineering students an opportunity to gain a “broader view” of the communication process.

Impedance Measurement: The R-X Noise Bridge -- Jay Slough, K4ZLE

When it comes to antenna evaluation we hams are most familiar with SWR or more correctly stated VSWR measurement. Virtually all active amateurs have some method to determine SWR. However, if that is all we measure, our view is incomplete. While the R-X noise bridge is not the most accurate test instrument, it does provide a more complete picture than a SWR bridge alone. It is also less expensive than most of the other tools normally associated with impedance measurement. This presentation is intended to unveil R-X noise bridge capabilities for practical evaluation applications. We'll see some comparisons with other impedance measuring tools and techniques including the so called "Three Meter" method. We'll wrap up the presentation with a quick look at some remote/automated impedance measurement techniques utilizing our 2007 Atlanticon kit as part of the hardware.

Antennas for Urban Towers -- Victor Dively, KG4HTT

Antennas for Urban Towers (attic antennas)" will focus on compact antennas that can be used even in small attic spaces. I will discuss four basic groups of "small" antennas: bent dipoles, end fire arrays, "medium" loops (loops from 20-80% wavelength in circumference), and loop arrays. You can work 80M-10M QRP, including plenty of DX, with antennas that are 20' x 20' or less in size. I will also discuss antenna materials and construction techniques, including my favorite material, refrigerator tubing. I will also include illustrations of the results I get with these antennas when I enter QRP contests as well as the CQ WW, CQ WPX and ARRL DX contests. QRP operating gives you a special thrill when your call is heard by a far-off DX station; that thrill is even higher when you have done it with a 10 ft. x 10 ft. attic antenna. 

Ninja QRP Op Evolution -- Ron Polityka, WB3AAL

Learn about the history and development of the Ninja QRP Operator from the early years up to his present excursions out on the Appalachian Trail. He will provide some helpful tips on how to make a memorable hiking and camping trip. If you have seen Ron talk before, you know that it will be an entertaining time. Remember to look for the Ninja QRP Op hiking the halls at the Atlanticon 2007 Forum.

 

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Last Modified:  March 31, 2007