RX-2 RC toy chip

[minigmh]

Hi All,
I found a wrecked RC airplane, brought it home and mapped out the circuit board. It has a RX-2 IC on it, which I found lots of info about on the net. The resistor across OSC1 and OSC2 is 330K. Do any of you know if that would correspond to a 49MHz toy or a 29MHz toy? It would be neat to find a chart of resistor values vs. frequency received.

 

[JimB]

I am not familiar with the "RX2", but a few minutes of googling tells me that the RX2 chip does not define the radio frequency, there is a separate receiver circuit.

The OSC1 and OSC2 seem to set a frequency associated with the controls, not the radio frequency.

I am prepared to be proved wrong, but at the moment I am sure that I am right.

JimB

 

[minigmh]

I think you're right, Jim. The left half of the circuit board is mostly RF stuff, and the right half of the board is mostly an H-bridge for driving the motors. The RF part makes use of 5 pins on the IC: One is for the processed signal input, and the other four go to two op-amps used for signal cleaning and conversion to pure digital. Therefore, I will conclude that the OSC1 and OSC2 pins are unrelated to RF reception. So... I guess the 330K resistor tells the chip what "baud rate" to expect of the input.