Last weekend, I had some mysterious issues with my RC4 transponder (bought December 21, raced nine races without any problems). Looking for advice on how to avoid the problem in the future or potential leads.

Background:
* I raced the same car in stock and modified, so two runs per round. Only switched battery pack and body shell. The transponder was the same.
* I used a Sanwa MT-44 with the standard receiver.
* I have a motor fan connected to the receiver.
* The transponder is mounted on top of the steering servo in my B6.3.
* None of these things changed since the previous 9 races during which I had no issues. The only thing I tried during the weekend was to switch the transponder cable from channel 3 to 4.
* I had no issues in controlled practice on Saturday morning.
* It was very hot that day. However, my transponder was the only one to cause trouble in a race with some 40 drivers/cars.
* The signal was OK according to the mylaps timing software.

My observations:

Q1: all laps counted in stock, all laps counted in modified
Q2: one lap not counted in stock, one lap not counted in modified
Q3: all laps counted in stock, all laps counted in modified
Q4: all laps counted in stock, all laps counted in modified
Q5: all laps counted in stock, all laps counted in modified
Q6: all laps counted in stock, all laps counted in modified
finals round 1: one lap not counted in stock, all laps counted in modified
finals round 2: one lap not counted in stock, all laps counted in modified
finals round 3: four laps not counted in stock, two laps not counted in modified

Any help is appreciated.

I did read somewhere you have to unplug the white wire of the transponder to get a maximum signal.
Sadly it is not official mentioned but it seems the solution for a low signal and bad hits.

since signal was strong I would not unplug any wires. might have been loops location on track that has happened to me a few times in my 12 years running mylaps.

They should be able to see your signal strength with the white wire removed and with it in place. FWIW, I have mine setup on the backside of the servo on my B6.4.

For me it always means a wire is breaking at the connector.

This happens fairly often at the club in my area and most common remedies:

1) Check steering servo throw, if over extending can be causing brown out if steering is full lock when crossing the loop
2) Check ESC fan/temps, (re-solder ALL wiring) can be getting brown out @WOT when crossing the loop
3) Check connector to PTX, look for loose wiring/pins, a fresh crimped connector can also fix the issue
4) Check location of PTX, move away from other electronics, especially the motor
5) consider increasing voltge on BEC to 7.4V which improves efficiency and increases power to PTX
6) as a last resort, hook PTX directly to battery by the balance leads

You can remove the white/gray wire without any problem, its just the "telemetry" of the PT itself (it can report back some values like BEC Voltage and Temp of transponder), just put it out of the reciver plug and the problem is solved.
PT works without any problem with just red and black.
Signal strengh is not everything, the signal can be good but corupted, so just remove the cable and all good

Yep, the white wire is for future telemetry like products to interface. Now only the voltage and internal transponder temperature is received but through this wire more is possible like an external temperature sensor but it is waiting when Mylaps do come with such products.

Meanwhile connecting it to a servo channel it will pick up the servo signal and maybe ruin/interfere the transmission. Again, I do not know the reason what is happening but saw a discussion of disconnecting the white wire as a solution for missing laps. One of the options is to connect the transponder on BATT connector where with most receivers the signal pin is not connected.