PPM Signal

[Bingojamas]

I am converting this Futaba FP-5FG using the DHT module. It works fine with the AM module installed and appears to be brand new. I am planning on using the AM module's pin locations on the tx to attach the DHT module as has been done successfully by others. My issue is that I cannot detect a PPM signal on what I understand to be the PPM pin on the tx ( Pin 5, or furthest to the right, facing them). I do measure +9V on the other respective pins, 2 and 4. Also, I am able to detect and measure a healthy PPM signal on the proper trainer port socket location. Any thoughts on would be appreciated. Thanks

 

[Glenn Beer]

How are you determining the presence of a ppm signal?

 

[Bingojamas]

With an oscilloscope. Actually, I checked it again and measured a very small signal at about 13 mV peak. I went ahead and hooked up the DHT module and it worked fine. The signal then measured about 3.8V peak. I don't know why this is so and need to learn a lot more.

 

[Wayne]

Glad you got her going. Those radios usually convert well.

 

[HENNY]

This radio looks brand new, did you purchase it yesterday.

 

[iflyj3]

With an oscilloscope. Actually, I checked it again and measured a very small signal at about 13 mV peak. I went ahead and hooked up the DHT module and it worked fine. The signal then measured about 3.8V peak. I don't know why this is so and need to learn a lot more.

The output from the encoder is an open collector. The pullup resistor to +V is in the RF module. That is why without the module installed you show very little voltage change.