The Obscura FM project involves a bicycle based FM radio station. After finding information that the C. Crane Digital FM Transmitter
is easily moddable
to extend the range to 100 feet we decided to give it a try.
Cracking open the case and cranking up the power took all of two minutes. It was more of a challenge to figure how to mount the transmitter on a bicycle or rider in a way that allows for good signal transmission and keeps the audio device within reach so the rider can manipulate the play list and pause when needed
The owners manual suggests that the transmitter should be placed in the highest location possible. On a bicycle that's on top of the rider's helmet and it just so happens that my helmet has a lug on the back for a safety flasher. Add a couple of zip ties and some scrap intertube to dampen vibrations and now my helmet is the Obscura FM transmitter.
A test ride was conducted to check performance and range. I headed out to the undiscovered country, the part of Summerwood where there are miles of empty streets with no houses. I had to take a massive detour to avoid the mosquito control department's chemical warfare truck. The new transmitter is a lot louder than the old one. I had to decrease the volume in Pocket Tunes
to get clean sound without distortion.
When I made it to the un-discovered country I found a stack of bricks and set the transmitter and phone down and rode away. Range confirmed at around 100 feet un-obstructed. Also interesting to note that on the way back I had to get within 40 feet of the transmitter before my radio was able to lock on to the signal.
The helmet mounted transmitter arrangement is nice. It makes it a lot easier to manipulate the phone when I need to skip a song or pause the stream. My only concern is the coiled cord on the transmitter. It doesn't seem very strong and putting the phone in my pocket means the cord is going to get constant tugging as I pedal. We'll bring the Hong Kong transmitter as a backup unit just in case the cord fails.
On the return to base I crossed paths with the chemical warfare truck. I quickly turned to escape but it was too late. He spotted me and the chase was on. I hit top gear and managed to stay just out of range eventually escaping via the tunnel under West Lake Houston Parkway. Luckily I remembered to duck or I would have sheared the transmission antenna.
Obscura FM is recruiting riders to join us at the 34th annual Houston Moonlight Bicycle Ramble
. In addition to your bicycle and required safety gear you will need a battery powered FM radio. Look for the tiki torches in the parking lot before the ride.
Next scheduled test ride is Thursday September 28th, 21:00 hours in Summerwood. (Near BW8 and Kingwood Atoscocita on the NE side of Houston) Barring mechanical delays we usually ride 20 miles and finish some time past 02:00. Email me
for directions if you would like to attend. Training rides are a good thing. The Moonlight Ramble is a lot more fun if you're not out of breath and in pain.
Tags: bicycle pirate radio, houston moonlight bicycle ramble, obscura fm, obscura mobile wing