FRSKY DIY module in JR Max 4

[Ugly]

I have recently fitted a FRSKY DIY module to a JR Max 4chn FM transmitter, (two in fact) the problem is that the TX and RX (two different units) bind OK but do not pass the ppm signal, the ppm input to the module is around 5Volts, the TX was functioning OK with the JR RF module (36 MHz) in circuit, Possibly polarity of the ppm signal ?? may need to invert the signal, insufficient Voltage, though I would think the pin diode would solve that issue, I have previously converted a couple of my old Kraft rigs and they have work great for over a year now, hopefully it is not a JR issue as I have a couple of later computerized JR sets that I would look to get off of 36 MHz . I would appreciate any feed back if you have any thoughts

Ugly

[RCModelReviews]

I can't think of any immediate reason why it should not work -- I think the DIY board handles both polarities of PPM signal (but I could be wrong).

Have you scoped the PPM signal?

[quarry44]

If you've connected the diy unit directly to the main tx processor,you may have the wrong pin connected.I had a similar problem,and found I had connected the yellow(ppm?) wire to the wrong pin.test the other available pins is about all I can suggest.