How to get PPM output from Futaba FP-T4L?

I just got a Futaba FP-T4L 4 channel 72 MHz R/C transmitter from a yard sale. I opened it up and there is no PPM output. The whole radio system is on a single PCB with the wires from the joysticks going to it. I have no receiver for it and want to replace the radio system with a 2.4GHz module. How would I go about doing that? Has anyone done this before?


Here is the last picture.
EDIT Some progress. The PCB is split into 2 parts and a IC on it is labeled “L9362”. The thing is powered by 8 NiMH batteries. There is also a power indicator which goes up to just above the red section. The indicator is on the front.

Replace the electronics with a Promini and a nrf24L01+ module? maybe this for power source

Well, I just went on and found out that the L9362 chip is well known and has PPM output on pin 9. I think I will need a resistor divider. What resistor values should I use to reduce 9.6V to 5V?

The transmitter PPM output appears to not be giving me anything, so I have decided to use it as either a trainer or a joystick with UnoJoy.