QRP Forum Speaker
James Bennett, KA5DVS
"Practical and Portable Antennas"
For those QRPers who have been
living a sheltered life, KA5DVS is the designer of the award-winning PAC-12
portable antenna introduced last year. His fabulously-simple and efficient
portable antenna design took top honors in the HF Pack "antenna
shootout" in 2002, and was chronicled in a feature article in QRP
Homebrewer #8 over the summer. (The project and article was so
exciting and popular that it was also made fully available online at http://www.njqrp.org/pac-12).
See the "About James" section below, as it tells so much more of what
drives him to the creative designs he's given to our QRP and antenna
I recently had dinner with James and his wonder wife Kathy and he was sharing many ideas he's got queued up for presenting at this year's Atlanticon. What a wonderful treat we are all going to be in for! There will be a surprise long the way too, so you really want to get in on this when it originates at the Atlanticon weekend. To quote James ... "I am always fascinated that the small amount of power our QRP radios produce can even be detected, much less carry information. To me, it is still magic that a radio with some metal and wire can send a signal to far parts of the globe, and to do this with low power and an antenna that I have built never ceases to fascinate me."
It is this fascination that drives James to experiment with many different materials and portable designs, and it is this same fascination that will delight and entertain QRPers attending Atlanticon this year!
About James Bennett, KA5DVS ...
I was first licensed in 1979 while in high school in Arkansas and today have an Advanced class license still with that original callsign. I started in ham radio when I asked one of the teachers what all the antennas on his car were used for. Within a year, I had my novice license. My first contact was with a 8 call area station and I was pretty nervous. From an early age, I was always interested in radio communications. I received a pair of walkie talkies that operated on 27Mhz. Not being happy with the 1/4 mile or so range the small antennas gave, I soon built a base station and bicycle antenna using copper wire wrapped around fiberglass bicycle flag poles. I managed to use somewhere around a half wave of wire and the antennas worked well. I was able to maintain communication with my brother at home up to about 1 miles away from by bike. Since the walkie talkies were low power, I was also doing QRP without knowing it.
Once I got my ham license, and got my first radio (Heathkit HW 16), I needed antennas. Living in the hills of northwest Arkansas, antenna parts were not the easiest to find. I ended up building a fan dipole for 40 and 80M using #14 copper wire and PVC fittings for insulators. The antenna got me on 80, 40 and 15M and produced many enjoyable QSOs. I eventually traded up to a Drake TR4C and adapted a 10 and 15M groundplane vertical using plans from QST. I also experimented with other vertical designs with varying degrees of success.
I earned a BS and MS degrees in Physics from Hendrix College in Conway Arkansas and the Univ. of Arkansas, Fayetteville respectively. During college, I lost interest in radio and it wasn't until I was attending graduate school that I rekindled my interest. I learned of the U of A club station, W5YM and was soon a member of the club. The club station was across the street from the physics building and I would operate late at night for a break. During this time, I converted a CB board to 10M FM and had lots of fun making contacts.
Ham radio took a back seat when I went to NJ for my first job moved into a small apartment. I did build a couple of the Ramsey kits and put up an indoor dipole but it saw very little use. When we bought our house in Hightstown, NJ, I finally had a basement for a shack and yard space for antennas. I also picked up a Yaesu FT301S at a local hamfest to get back on the air. I first put up a simple loop antenna for 40M and up and used it for a while. However, I have always liked vertical antennas and soon I began on a design. I ended up using 30' of copper tubing which I painted green to blend in with the spruce trees in my back yard. I build a relay switched tuning network at the base and I was soon on the air on all bands. About this time, I also discovered QRP-L on the internet and found that there was a small group of QRPers that met in the central New Jersey area. I attended a meeting and became member #9 of the New Jersey QRP Club. Ham radio began to be a lot more fun than it had ever been and the rest, as they say, is history.
Over the years, I have always enjoyed designing and building antennas. Some might say I am cheap and they are probably correct. However, I find it a challenge to go into a hardware store and come out with parts to build an antenna. I also find satisfaction making contacts with an antenna built from scratch. I've always favored vertical antennas as they can be fit into smaller space and don't require tall supports to work well.
The PAC-12 antenna was another example of an antenna born of a need. In 1997, I moved to California to join a startup company. The company grew and I soon found myself traveling quite a bit on business. I build a K2 and took it along on many trips. I used dipoles and random wires but the lack of supports in some locations led me to look to a self supporting design. Once again, I was cheap and decided to build a travel vertical antenna. I browsed the local Home Depot and eventually ended up with PVC and aluminum rods. This, along with a 72" whip from Radio Shack, became my travel antenna. It went through several iterations eventually ending up as 12" sections for easy portability. I chose to make it center loaded to improve efficiency. Along the way, I bought a Yaesu FT817 for travel and it has accompanied me on many trips with my antenna.
Today, I continue to work on several portable antenna designs with the goal of optimal efficiency, minimal weight and portability.
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