Bicycle Mobile
After all the fun of using ham radio on a backpack and in a boat, I decided to see if I could mount my FT-817 to my old (1986) Miyata mountain bike. I wanted to operate QRP and knew I wanted a big antenna, but now I had legal regulations to follow. My trusty 20-foot shortened half wave would take me nine feet over the 13.5-foot limit for a vehicle on the road if I mounted it on the bike rack. With some calculating and some trial-and-error, I came up with a 13-foot, very shortened half wave vertical. Even this would be too tall when mounted 30" above ground on the end of the bike rack, so I tilted it back about 40 degrees.


I found the camera bag at a garage sale for two dollars. That's my FT-817, sitting on four inches of foam. Below that is the headset adapter. A pre-made six-foot BNC-BNC coax cable just reaches from the rig to the antenna in the back. The bag rests on a coated piece of 7" x 7" plywood, and that is mounted to the handlebars with aluminum brackets. Rubber from an old inner tube is sandwiched in between for more shock absorption.


In June, 2005, I temporarily replaced the radio with an IC-706. Running 20 watts I worked New Zealand from Golden, Colorado.
Here is a short report (with audio) on an amazing three-hour ride and my QSO with ZL1AIX.


Below is a closeup of one of the two coils that make the antenna an electrical half wave. Using the full coil gives me 20 meters. With the alligator clip connected to the tap, it is 17-meters. I used 20ga insulated, stranded wire wrapped around thin-walled 1.25" PVC pipe, then covered it with electrical tape.

The antenna is mounted to the bike with an assortment of PVC pipe fittings. the support is made from a 3/4" tee, two elbows and pipe. The antenna rests on a riser made of 1/2" PVC pipe. All of the PVC was painted black and given a coating of Polyurethane. The whole thing is held to the bike with hose clamps. The blue box is a home brew high-Z matching unit.

September 1, 2004
Just a few minutes after this picture was taken, I was a block from home and making my first QRP bicycle mobile contact with KC5IJP in Mississippi.