[knighthawk]

Mark,
I don't work for either Mylaps or BBK Software so can't comment, I'm a customer and as such accept the price given for the product and make my mind up if to buy or not.

More facts

RC4 Decoder testing at Rug Racers 2nd December 2012 Part 2
We did some testing at the Rug Racers event to check if the AMB and Mylaps Transponders were behaving at a race as they do in our bench tests. We compared the performance of the transponders detected by the RC4 Decoder and the RC2 Decoder used to time the event. Of particular interest were the number of "hits" detected. In simple terms the more "hits" the less likely a "missed count". The following table shows the average % ratio of "hits" detected by the RC4 Decoder compared to the RC2 Decoder for the same transponder. the number in () is the total number of transponders of each type.

The absolute number of "hits" for a particular transponder type varies from car to car, depending on the position of the transponder and the components around it. To work reliably the signal has to be detected as the car approaches, crosses and leaves the loop and the time and strength of each "hit" is used to calculate when the car crosses the loop. The more "hits" the better the accuracy. For each passing the number of hits will vary slightly. I have seen instances of the decoder getting less that 10 hits from some transponders and by moving the transponder to a better position the number of "hits" increases. If there are a low number of "hits" then sooner or later a lap will be missed.

To get an accurate time of crossing the loop the car needs to be moving quickly. That way the transponder is in one place (centre of the loop) for less time. Putting the loop in a slow part of the track was important when cars were manually counted but we haven't done that for over 20 years. The best place is on a fast part of the track where the cars can safely go flat out. Racing to the loop in a slow part of the track on the last lap of qualifying is dangerous for marshals.

As cars get faster and carbon fibre and to a lesser extend alloy is used in chassis material we need a "better" transponder signal. Both carbon fibre and alloy block the signal. More detail on this can be found here Why do Transponders miss laps? Increasing the signal strength doesn't help as it results in transponder pickup over a wider area for cars with good mounting positions. This just creates more problems with cars being detected on other parts of the track. More "hits" generated and detected per unit time improves accuracy and reliability.

In addition to improvements in transponder performance for new and old AMB/Mylaps transponders RC4 includes the Pure RC4 transponder (Purcy). Purcy allows several transponders with the same 7 digit number but an extra unique ID number. In some types of RC racing it is permitted to use more than one chassis during an event, in others it is not. The extra ID number is there so the Timing System can detect if more than one transponder is used with the same 7 digit number. Without this it would be possible to fake results by using more than one transponder, one in the car and one placed near the loop. As the RC2 and RC3 firmware cannot report the Car ID (it was developed later), Car ID transponders only work with RC4 firmware. The RC4 decoder can be used with software that is not RC4 "aware". In this circumstance the decoder will ignore a second Purcy transponder with the same 7 number for a timeout period. This timeout period can be controlled in the RC4 Decoder by the timekeeper.

RC4 Decoder testing at Rug Racers 2nd December 2012
We did some testing at the Rug Racers event to check if the MRT transponders were behaving at a race as they do in our bench tests. We connected an RC3 and RC4 Decoder to the loop that was being used to time the event. The event was timed using the older RC2 Decoder. The following table shows the % of passes recorded.

This demonstrates that all AMB/Mylaps transponders work reliably with the RC4 Decoders but MRT transponders do not, in fact only 1 in 5 PTX transponders recorded any laps at all. We have offered a trade in for MRT transponders in exchange for Harry transponders since April 2010 and continue to do so.2nd December 2012