Is there a cure for interference on the OSD and monitor caused by the telemetry radios? Everything works fine if they are unplugged but plugged in they create a mess on the screen. Funny part is, when I touch the cable, the interference stops. I’ve tried the recommended wiring diagram from the manual with the same results.
Sounds like you have a ground loop issue.
Are all devices grounded to negative terminal?
Here are few techniques I use to avoid such problems
Running devices from separate power source
Using a capacitor to avoid voltage spikes
Low pass filter.