To increase the transmission and detection of a radio rc car where can I attach the oscilloscope?

Question

in order to tune the transmitter and receiver coils. Would I hook up the oscilloscope to the detector stage or the AF amplifier stage on the receiver, or would I hook it up to the transmitter output stage. This is for a radio rc car electronics project, everything has been tested and measures as it should, but for some reason it will not respond wireless if more than an inch apart, it was tuned to work about a foot apart, but even that isnt enough, and now it is all out of tune and wont work at all.

Answer 1

Start your troubleshooting from the farthest ouput. If you are not getting the right signal, then work backwards until you get what you are looking for. Then the trouble will be between the farthest output and the point of the good signal

Answer 2

You can make life much easier for yourself if you connect the antennas through BNC connectors, and you put both the transmitter and the receiver in grounded metal enclosures. You can always take them out again after troubleshooting.



First, connect your transmitter to a dummy load. Measure the voltage across the load using the 'scope, and calculate the power. You should have at least 100mW, or whatever the transmitter was designed to produce.



Next, connect an RF signal generator to the receiver. Turn the voltage down until the receiver only just responds. You should be sending 1 or 2 microvolts at this point. If it takes more, then the receiver is not working properly. You cannot debug a receiver circuit without an RF signal generator.



After isolating the problem to the transmitter or the receiver, start troubleshooting whichever one is not working. If you can borrow a spectrum analyzer, check the purity of the transmitted signal as well. The r/c car will work with an impure signal, but you might interfere with other radios.

Answer 3

Sounds like you need to either:



1.) Boost your transmission power.

2.) Boost the gain of your transmitter (either antenna or amplifier).

3.) Boost the gain of your receiver (either antenna or emplifier).



What you really need to investigate the porblem is a spectrum analyzer and not an oscilloscope. The problem with the oscilliscope is that with all the noise it may be hard to pick out the signal you are trying to send.