bikemobile

Eight (or Nine) Bands on Two Wheels
VE3JC -- John Cumming -- email ve3jc@rac.ca

I enjoy combining QRP with one of my other favourite hobbies - cycling. In the summer of '98, I have been working on optimizing my bicycle mobile setup - for 10 to 80 meters, CW & SSB (the 2 m handheld usually comes along for the ride, too). The equipment consists of:

One very well-used 18-speed bike (a "Canadian Tire" special purchased about 12 years ago for under $200)

Index Labs QRP+, original version with no internal mods (I usually run 4-5 watts on CW, and 2 Watts on SSB which is the most my QRP+ puts out). At some point I will modify the rig for increased SSB, but I'm operating CW 95% of the time, so it's not a big priority.

Outbacker Perth 75-10 M Antenna

A Kenwood speaker-microphone, and Mini Paddle made by Gil Kost (American Radio QRP Key Mfg Co., email: ahber@ix.netcom.com)

7 Ahr Sealed Lead Acid Battery

DESIGN DETAILS

The following describes how I have mounted the equipment on the bike.

The rig is mounted in a handlebar bag, angled so the front of the rig is visible and controls accessible without having to take my eyes off the road. I haven't been using earphones - a "deflector" directs the audio from the top-mounted speaker to the rider (a la "his masters voice"!). Although most of my riding is on back roads, I find it surprisingly easy to copy, even in the presence of cars and cows! Leaning forward to reduce drag when going down a hill puts my ears very close to the speaker. Note that there is ample room in the handlebar bag for a small logbook and microphone.

The antenna is mounted on a 1" dia aluminum tube extending from the bike frame and rear pannier rack, about 1' behind the back wheel (led flashing light is also mounted on the end of this tube). Nice thing about this is that I can mount and dismount normally without touching the antenna. Also, the tube extension provides an increased ground plane for the Outbacker. The stinger must be extended to almost maximum to achieve resonance on most bands. I will publish swr curves here when I have time). Although there is some sway in the antenna (the top of the whip bobs back & forth with every stroke) I hardly notice the extension and antenna are there! The aluminum tube attaches to the bike frame using two plastic "U-lock" mounting brackets (50 cents ea. at a local junk store).

The aluminum mounting pole is anchored to the rear pannier rack using an "inverted" mobile antenna bracket and a good old Canadian hockey puck. Removal of the whole antenna system from the bike takes only thirty seconds: Undo the butterfly nut on this anchor, and slide the pole assembly back. (U-lock brackets on bike frame remain permanently attached)

The aluminum pole was cut from a folded dipole element of an old commercial antenna. The bend at the back permits mounting of a super-brite led flashing light. (This light unclips, and makes a great night light for portable operation from a tent)

The mini-paddles are mounted to the right extension on my handlebars. Some people have used contact switches in each handlebar extension (dit with left thumb, dah with right thumb) which may be marginally safer but not appealing to me.

My wrist remains on the handlebars as I am transmitting, so steering, shifting and braking are still convenient.

Some interesting findings so far...

- it's very tough to send good cw when riding on a gravel road

- the dial on the QRP+ is surprisingly rock solid. Frequency does not change even with severe bouncing on bad roads. I had previously designed and built a mechanical stop for the dial, but it's not needed. (BTW I have no front shocks on the bike, which is a dozen years old and worth much less than the equipment it's carrying)

- I can operate most controls with one hand (eg use two fingers on "speed" buttons and thumb on dial, to adjust cw speed "on the fly"). For some setting changes, I just have to stop and use both hands.

- Changing bands is no problem - a 15 second stop to change taps on theOutbacker, and back on the road.

- Bike mobile qrp is not for those who like to keep their rigs in mint condition. The scratches on my field radios show they have character. (I always cringe when I see a 'for sale: trail-friendly radio that has never been outside my environmentally-controlled shack' ad. Trail and bike friendly radios want adventure!).

If you hear me on the air, please give me a call. I would be happy to answer any questions you might have. Email me at jbcumming@wwdc.com or ve3jc@rac.ca

MY ELECRAFT K2 NOW BIKE MOBILE ON SSB!

If you would like more information on bicycle mobiling, check out: BICYCLE MOBILE HAMS OF AMERICA

Also, take a look at Russell KB8U's page for more ideas on QRP CW bike mobiling. Russell and I had a two-way QRP Bike Mobile qso on Nov. 1, 1998

"back to VE3JC's shack"

The rig is mounted in a handlebar bag, angled so the front of the rig is visible and controls accessible without having to take my eyes off the road. I haven't been using earphones - a "deflector" directs the audio from the top-mounted speaker to the rider (a la "his masters voice"!). Although most of my riding is on back roads, I find it surprisingly easy to copy, even in the presence of cars and cows! Leaning forward to reduce drag when going down a hill puts my ears very close to the speaker. Note that there is ample room in the handlebar bag for a small logbook and microphone.
The antenna is mounted on a 1" dia aluminum tube extending from the bike frame and rear pannier rack, about 1' behind the back wheel (led flashing light is also mounted on the end of this tube). Nice thing about this is that I can mount and dismount normally without touching the antenna. Also, the tube extension provides an increased ground plane for the Outbacker. The stinger must be extended to almost maximum to achieve resonance on most bands. I will publish swr curves here when I have time). Although there is some sway in the antenna (the top of the whip bobs back & forth with every stroke) I hardly notice the extension and antenna are there! The aluminum tube attaches to the bike frame using two plastic "U-lock" mounting brackets (50 cents ea. at a local junk store).
The aluminum mounting pole is anchored to the rear pannier rack using an "inverted" mobile antenna bracket and a good old Canadian hockey puck. Removal of the whole antenna system from the bike takes only thirty seconds: Undo the butterfly nut on this anchor, and slide the pole assembly back. (U-lock brackets on bike frame remain permanently attached)
The aluminum pole was cut from a folded dipole element of an old commercial antenna. The bend at the back permits mounting of a super-brite led flashing light. (This light unclips, and makes a great night light for portable operation from a tent)
The mini-paddles are mounted to the right extension on my handlebars. Some people have used contact switches in each handlebar extension (dit with left thumb, dah with right thumb) which may be marginally safer but not appealing to me.
My wrist remains on the handlebars as I am transmitting, so steering, shifting and braking are still convenient.