I'm on my third iteration of bike APRS, and the second using an FCC/301. This time I've been doing some experiments with fairly long rubber duck antennas. I've been using a discontinued Radio Shack scanner antenna which claims to offer 2M and 70cm TX, and is thick enough not to whip in the wind.
It's presumably a shorened 1/4 wave, not like your half-wave, and so needs a ground plane. I had thought that capacitive coupling through the BNC mount on the pannier rack would be enough, but when I tested it with a miniVNA antenna analyzer, I found a poor match until I had a good connection. On 2M, it went from 3:1 minimum to 1.5:1 minimum once I scraped off some paint of the BNC mount and verified DC connection with an ohmmeter. You can see the antenna mount at the top of this picture: http://wa5znu.org/2009/09/bike-tracker2/tn/2009-09-07%2014.37.06.jpg.html This is the cover I made from the bottom of an extra-large index card file. http://wa5znu.org/2009/09/bike-tracker2/tn/2009-09-07%2014.37.58.jpg.html It fits on top of the pannier rack with 19" cable ties. I'd like to make a stronger cover out of ABS and use bolts under the rack to hold it on, but this will do for now. Leigh/WA5ZNU Dave Ingram VK4TDI wrote: > > That sounds like what I need for an upcoming bike ride. I'm intending to > put the Tracker2/FC301 on the back of my bike when I do the 100km ride > from Brisbane to the Gold Coast. The last time I did the ride I used the > OT1+ but digi coverage was poor at the start of the ride. Coverage is > much better now, so tracking will be tried again. It is a bit of a > conversation starter with about 5000 other riders when there is a 1.2m > whip hanging of the panier rack :-) > > > Dave. > >
