I have a Guardian iPad mini mount which I am trying to connect with my PS PAR200A intercom. The wiring diagrams are kept on-line at Guardian's site. The power side of thing is fine, but there is nothing concerning the audio - which SHOULD be simple.
The intercom (PAR200A) expects audio left, audio right and audio lo. The supplied Guardian cable has a 3.5mm music jack which fits the iPad headphone socket. It has audio left, audio right, ground and mic - this should be the configuration from the jack tip inward. The 2 audio channels are fine (red and white). Ring 3 doesn't seem to be connected to anything. Ring 4 is connected to purple with 6.7k resistor. The final wire (black) gives 6.7k across the purple wire but nothing on anything else. I can't even work out a wiring that exhibits these parameters!! I have also found a note on the PAR200A diagram saying NOT to connect Audio lo to ground as it is a differential music input. Well that's fine because neither of the "spare" wires is grounded - but where DO I connect Audio Lo?
Any of you avionics gurus throw any light on this.....
The intercom (PAR200A) expects audio left, audio right and audio lo. The supplied Guardian cable has a 3.5mm music jack which fits the iPad headphone socket. It has audio left, audio right, ground and mic - this should be the configuration from the jack tip inward. The 2 audio channels are fine (red and white). Ring 3 doesn't seem to be connected to anything. Ring 4 is connected to purple with 6.7k resistor. The final wire (black) gives 6.7k across the purple wire but nothing on anything else. I can't even work out a wiring that exhibits these parameters!! I have also found a note on the PAR200A diagram saying NOT to connect Audio lo to ground as it is a differential music input. Well that's fine because neither of the "spare" wires is grounded - but where DO I connect Audio Lo?
Any of you avionics gurus throw any light on this.....