"Do you have MYLAPS black box (impedance matching device) at the end of coaxial cable? Without black box you can't get low noise and good signal."

The trials I have run have been interesting.

I have the "official my laps" detection loop that you show a picture of. I made another detection loop with the excess wire I cut off of that without a resistor and it made no difference at all in the sensitivity or the noise level.

I tried 18 gauge wire and it was almost identical to the mylaps as well without the resistor.

I then tried a solid core wire rather than stranded which was somewhere around 18 to 16 gauge in size and the noise wasn't any higher, but it picked up the signal of the cars going across it better.

So, at least in my installation, the resistor made no difference at all in the performance of the noise or the signal from the cars.

Shannon