RIDING THE AIR WAVES
By Scott A. Farrell, KE4WMF (Bicycle Mobile)
Revised as the bike changes. CLICK HERE to read the original article as it appeared in CQ VHF in February 1998.
Can bicycling and Amateur Radio coexist as one activity? Absolutely! Bicyclists often choose to ride their bicycles in order to exercise, seek adventure, save fuel, and avoid stop and go traffic. Amateur Radio operators often have ham radios in their automobiles for emergencies and so they may operate them outside the confines of their homes. There is no reason why someone cannot enjoy a good bicycle ride while having the benefits of Amateur Radio. Here is a little about myself and how I integrated my two favorite pastimes:
I joined the United States Coast Guard in 1986 and bought my first road racing bicycle in 1987. I was a licensed road racer and I had always been a fast recreational rider, averaging about 500 miles per month. Lots of time has passed since those days, including a long hiatus from bicycling. These days I prefer to log my miles riding in organized group rides and exploring off-road areas. I'd love to return to commuting. But I'm 40 miles from work and there are restrictions to bicycling along the way such as bridges, tunnels, etc. I still have my old racing bike, but I mostly ride my TREK Y5 full-suspension all-terrain bicycle. My daughter and I also ride the tandem my wife and I bought as newlyweds in 1991.
I began Amateur Radio study
while stationed aboard a Coast Guard cutter. Studying for the test was not difficult since I'm trained in radar,
computer, and digital circuitry repair. But procrastination was easy while at sea. I eventually committed to taking an exam when a bout of walking pneumonia sidelined my bicycle commute for a few months. I received my Technician Class license in March 1995 and bought
a YAESU FT-11R 2m handheld transceiver (HT) to use during the morning and
afternoon commutes. I started riding my bicycle in the Spring when my health improved. Soon, I was making the 22 mile round trip commute to and from work,
just as I always had when the roads were ice-free. Then the thought occurred
to me, "Why should I stop talking to all of these wonderful people on the radio just because I'm on a bicycle?" I began carrying the HT with me; but the rubber duck antenna just wasn't
performing well enough. That's when a series of modifications began.
My first modification was to upgrade the antenna. Since about 80% of my hamming was done from a bicycle, I've learned a few things about what is important when working bicycle mobile. I believe the most important element of a bicycle mobile station is the antenna, especially one that does not require a groundplane. Here is my station now, starting with the antenna and working forward:
| My antenna of choice
is a LARSEN NMO-150HW half-wave. Copper wire "J-poles" are great, but they're
a little awkward on lightweight bicycles and they take
a real beating in the woods. I find the Larsen to be light and nimble, easily
flexing around low tree branches and other obstacles in the woods. The Larsen
does not require a groundplane; so the mount was made as small as possible.
Although the 5/8-wave antenna is considered an axiom for mobile applications,
the 1/2-wave is much more effective, yielding SWR readings below 1.3:1 across
the band. The coil is a great place to mount a flashing tail light, too.
The antenna is mounted to an aluminum panel which I fabricated from a small sheet of aluminum. I chose to use GOOP Household Adhesive to attach the panel to a rear cargo rack. Unlike superglue or epoxy, Goop is not rigid when dry. Therefore, the mount has held up well under various conditions, particularly under heavy vibration where superglue or epoxy had cracked. Several coats of gloss black paint finished the job and hid the glue.
Moving forward, a 12V 8Ah gel cell by POWERPORT is kept on the cargo rack along with an old Realistic 30W 2m amplifer (light use only). The photo at left depicts how and where the equipment is normally stowed within the trunk pack. The equipment in the trunk pack connects to the handlebar equipment via cables which run along the bicycle's brake/shifter cable path.
| My FT-11R rests in a homebrewed
handlebar mount created by gluing and screwing the mounting pieces of a
retired bicycle headlight to a small carved up Radio Shack project box. Any headlight
will suffice as long as both the piece that mounts to the light and the piece
that attaches to the handlebar are available. Again, Goop was used to secure
the mounting pieces to the HT case. Initial tests revealed that superglue cracked
during heavy vibrations off-road. Goop has not failed me yet, even after crashes.
I reinforced the HT mount by adding thick Velcro
straps and special cutouts so the HT will not fall off the mount in bumpy terrain. The finished
product is a fully adjustable handlebar mounted HT mount with full keypad/display
access and quick-release features.
The final part of my ham setup is an SPM-400 boom speaker/mic by PRYME RADIO PRODUCTS. It rests on my ear and does not interfere with my helmet straps. The PTT (press-to-talk) switch is very small, can be mounted almost anywhere, and it gives me hands-free operation. The combined weight of the bicycle and the ham rig is just over 35 pounds. Many would say that's entirely too heavy. But I believe my choice to mount my radio to a full suspension bicycle may prolong the life of the equipment since normal jolting is significantly dampened (my wrists and rear end appreciate the suspension ride as well). My design's only drawback is the equipment's vulnerability to damage in a crash. Since I usually lay the bike on its side in a crash, the equipment should be adequately protected by the handlebar ends. A brutal crash proved that I am more susceptible to broken parts than the radio or bicycle.
includes a homebrewed voltage monitoring and switching box, a
CygoLite dual LED headlight system, a Cateye Mity 8 multifunction
cyclocomputer, a first-aid kit stuffed into a dummy water bottle, and a roadside repair kit. My goal is to make my
bicycle mobile station available for use in community events such as bicycling or run/walking events where automotive and pedestrian communications are impractical.
Overall, I'm very happy with what I have. I'm sure I don't have the greatest station in Amateur Radio; nor do I have the lightest or fastest bike on the road (although I surprise a few riders by occasionally maintaining an A-pace during group rides). I've traded some performance for weight and size. Still, I'm able to use just about any 2 meter repeater within 10 to 15 miles (65 miles is my 2W record). I think it's interesting that I was able to take two hobbies and combine them into one. Fellow cyclists have to agree that I am one of the safest cyclists to ride with because more help is just a quick call or telephone patch away, especially if our ride takes us someplace with spotty cellular coverage. One thing is certain: I can't complain about the performance I'm getting from a BICYCLE station!
Click here to read about my longest bicycle mobile ride, the Armed Forces Cycling Association's Tour of the Southeast.
Click HERE to read about BICYCLE MOBILE HAMS OF AMERICA, an international club for Bicycle Mobilers.
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