Originally Posted by
lolachampcar
I just made a simple cable that goes in line with the audio jack of my head set (or just plugged into an open audio plug of your intercom) and it works very well with a Drift HD recorder I am using to record aerobatic work. The circuit is VERY simple and consists of a 10K Ohm resistor tied to the audio source (tip of male audio plug) then a 10 microfarad ceramic capacitor in series with the other leg of the capacitor run to the mic input. The mic is then effectively capacitively coupled to your audio source which isolates the two circuits (protecting both). There is also a 10K source/load impediance (the 10K resistor) which limits any higher frquency current (again, protecting both devices).
so.... tip of male audio jack to one side of 10K 1/8th watt resistor.
other side of resistor to one side (either) of non-polarized 10 uF ceramic capacitor (5 to 25 or higher volts.... not critical)
other side of capacitor to mic level input of your recorder
Interesting! I've been looking like crazy for a simple solution like this! I will also be using this for the Drift HD170.
1 question though.. Is the audio source and mic input grounded together?
// Space