Transponders

A table with the current assignment of transponders is available HERE. This list will be regularly updated. If you think you have a different number to that listed, please contact your club. Also check what number you have been assigned on the start list each week and if you think it should be different let someone know at sign-in (or before).

The transponders issued over 5 years ago are nearing their end of life where the non-replaceable internal battery dies. The club will gradually replace transponders as they fail at a cost of $100 to the member and these should last another 5 years. The timing officials monitor the battery status every race and will advise you when it’s getting low and due for replacement.

The transponder system we used is called an “Active System:. The transponder is battery powered and has a microprocessor that fires off a signal when it crosses the timing loop. The battery will die at some point, and cannot be replaced. When the transponder is not being used, it goes to “sleep”. Care of your transponder when not being used can prolong battery life, eg – don’t leave the transponder in the car if you have “keyless ignition”, and don’t store your transponder close to electrical wiring are a couple of basic points to remember. Whilst it’s unlikely that stray electric signals can wake a transponder, it’s not unheard of.

We have conducted tests with various configurations and can confirm that the distance from the transponder to the ground is critical, as is its orientation. When the timing loop wakes up your transponder, the transponder starts emitting signals. The timing unit then captures all the signals sent, and does a calculation to determine the centre point from 1st to last signal seen and stores that as your finishing time. The more signals sent, the more accurate the result. If your unit is poorly positioned on the bike, you are going to impact negatively the number of signals captured as you’ll be waking it late and putting it back to sleep early. Situating it on your handlebars halves the capture range compared to the recommended fork mount. Mounting it flat further reduces it to the point it either doesn’t register or gives a highly inaccurate time..

In short, mount the transponder on your fork for best operation

TIMING SYSTEM OPERATION

A description of the Timing System Operation is here.