If the AMBrc Personal Transponder is not powered from the Receiver
If you have a 2 channel receiver and the battery socket is used or does not provide power to your PT then you need a Y lead, to share either the Channel 1 or Channel 2 socket between a Servo/Speedo You can buy a Y lead from your Local Model Shop or online form our WebSite. Click here for details.

AMBrc Personal Transponder Counting Problems
There are two reasons why an AMBrc PT may not work reliably: Lack of power and weak signal.

Lack of Power If the power to the PT is intermittent, it will not reliably operate and laps will be missed. With electric cars power to the Receiver and thence to the PT is usually provided by the Electronic Speed Controller via a BEC (Battery Elimination Circuit). The power rating of the BEC varies between 1 and 3 amps. FET Servos can draw significant amounts of current (even when stationary) and if they are powered from the BEC circuits of a Receiver they may cause the voltage to drop below 4 volts. This will shut down the PT until the voltage rises above 4 volts. If you are using a 6 volt FET servo powered from the Receiver make sure the BEC circuit of the Receiver can supply enough current to ensure this problem does not occur. If you are using a 7.2 volt FET servo powered directly from the car battery, this problem will not occur. 

There is another possible reason for lack of power: If the PT is plugged into the receiver the wrong way round, it may not work at all or it may work intermittently. Make sure the plug is the correct way round!

Weak Signal The signal from the Transponder is screened by aluminium or carbon fibre. Graphite and plastic will not screen the signal. If you are experiencing a weak signal from your Transponder (Race Control/Timekeeper will be able to advise you if this is happening) you should review the position of the transponder. Assuming the loop is under the track, the PT should be mounted as low as possible. It should be mounted with the printed side (with the power LED) facing either up or down as the signal is directional. If you mount it on its side the strongest signal will be directed away from the loop.  If your chassis is aluminium of carbon fibre you should mount the transponder above the chassis and at the edge so the transponder can "see" the loop.

AMBrc Personal Transponder seems to cause interference
If you car "glitches" with a PT fitted you may need to position your PT away from the receiver. To find out if your receiver is getting interference from the PT try the following. Switch on the Transmitter with the antenna retracted and place it a few meters (yards) away from the car. Switch on the car with a PT powered by the receiver but not attached to the car, so you can move it around. Hold the PT near the receiver antenna. You should not get any interference. Now move the PT near the receiver. If the car "glitches" then the receiver is not shielded and is getting signals from the PT. We have found some receivers are very prone to this while others are 100% immune. If you do get this "glitching" there are two of things you can try. The first is to move the PT away from the receiver. If this is not possible then you can try wrapping the receiver in metal foil.  

Another general cause of interference is coiling of servo and speedo wires. They look pretty but the coil acts as a magnet for radio signals and will feed interference into all the electrics in your car.

AMBrc Personal Transponder mishaps
The AMBrc Personal transponder is very rugged but there is a way you can kill them. If you have a nitro car you may well have a NiCad receiver battery. If you charge this in the car make sure that you don't accidentally plug the charger into the PT instead of the battery. If you do your PT will never work again!

Back to AMBrc Information Menu