Pretty simple, I think
N788RV said:
I have a PS Engineering PM3000 intercom. It has two auxiliary inputs. I have audio from my Dynon D120 and the AOA sport. I have separate prewired harness.
The auxiliary inputs on the PM3000 box have two strand shielded wired labeled audio high and audio low.
The AOA sport has a single shielded wire labeled audio
the D120 has a single unshielded wire labeled audio.
I also would like to run the D120 audio through a 10K potentiometer. I'm not sure how to handle the audio high and low with a single wire and what to do with the shields. I do have extra DSUB pins and crimps if necessary.
High Low: High refers to the hot or audio and Low to the ground. You need the HOT but not always the ground.
On your AUX1 simply hook up the AOA's center wire to High (pin 17?) and shield to Low. The issue with the Pot is a non issue, just the HOT goes thru the pot as I suggest below. The low or ground by-passes.
On your AUX2 simply hook up the D120 single wire to High (pin 4?)and leave the Low not connected. It should work fine. If you want a pot (potentiometer) just wire per below.
You say you want a volume control/potentiometer? Any taper "audio" potentiometer should do. 1k 5k, 10k ohm? Any will work. Power rating (watts)? Can be very small since we are talking about milliwatts audio power. It just gets wired in series between the AOA or D120 and PM3000.
The way I would wire the potentiometer is with the output (HOT or HIGH) from the AOA to terminal #3 (in) of the Pot; Terminal #1 (out) and #2 (wipe) are tied together go to the PM3000. This is shown as (variable resistor) below.
Again the ground or Low just by passes the Pot. There are other ways to wire with the shield, shown above as (volume control); these two are typical for this application IMHO. To learn more:
http://sound.westhost.com/pots.htm
You could consider an "audio selector" switch, a simple On/Off. Some AOA systems are a bit noisy on landing from what I have heard, push push push, on landing. I can see wanting to override that if the system does not recognize landing and takeoff.
