Odai
16th Jun 2012, 13:45
Hello,
I am looking at connecting my GoPro camera to an aircraft intercom.
I realise an option is to simply use a small mic tucked away inside the earcup of a headset but I'd rather connect the camera directly to the intercom for better clarity, and also comfort.
From what I have understood from the feedback I've received here, and internet research, there are three main issues to overcome.
Firstly, is physically hooking up the camera to the audio source. That should be easy as I understand it, I guess I could just use something like this:
Pilot Avionics PA 80 Video/Audio Adapter Cable (GA Twin Plug) (http://www.transair.co.uk/sp+Pilot-Avionics-PA-80-Video-Audio-Adapter-Cable-GA-Twin-Plug+2185)
From my limited knowledge, this kind of thing (available from many other pilot supplies retailers too) is simply a 6.35mm stereo plug extension with a 3.5mm plug extension connected in parallel, right? So I'm also assuming, as the 6.35mm is fairly standard/common, I don't have to look in a pilot shop for this kind of adaptor.
Secondly, is the issue of signal levels. I'm guessing the voltage used to drive beefy aviation headsets is a lot higher than that the camera will have been designed for? I did read (in my other thread) that some trial and error would be involved in solving this one, but I was wondering if there is a more concrete way to do it. Maybe matching impedance figures (again, totaly newbie here)?
Thirdly, and this is the one I'm totally clueless about, is the issue of a DC power source being present on some aircraft intercoms. This is referenced in the item description here:
AIRCRAFT INTERCOM RECORDING CABLE from Aircraft Spruce (http://www.aircraftspruce.com/catalog/avpages/recordingCable.php)
It says that the DC supply can, at best, cause a high pitched squeal on the recording, or damage the recorder if the voltage is high enough. However, from looking here:
TRS connector - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/TRS_connector#Aircraft_headsets)
It seems the DC power supply, if needed, will only connect to the microphone (through the often unassigned tip on the TRS connector), and not to the headphones (with sleeve being common ground, and tip/ring being two audio channels). And as I understand it, the camera would be connected to the intercom's audio output (which connects to the headphones, and therefore without DC power supply), not to the microphone input (where there would be a DC power supply connected to the tip of a TRS connector inserted there).
So how is it that the possible DC power supply is at all relevant to recording to a camera? Am I right in saying that aircraftspruce have built in a useless feature, or have I (probably more likely) totally confused myself?
I'd massively appreciate any feedback on these.
Also, I understand I had started another thread on cockpit cameras, but with the specificty of these questions I thought it might be useful to start a new thread.
Thanks!
Odai.
I am looking at connecting my GoPro camera to an aircraft intercom.
I realise an option is to simply use a small mic tucked away inside the earcup of a headset but I'd rather connect the camera directly to the intercom for better clarity, and also comfort.
From what I have understood from the feedback I've received here, and internet research, there are three main issues to overcome.
Firstly, is physically hooking up the camera to the audio source. That should be easy as I understand it, I guess I could just use something like this:
Pilot Avionics PA 80 Video/Audio Adapter Cable (GA Twin Plug) (http://www.transair.co.uk/sp+Pilot-Avionics-PA-80-Video-Audio-Adapter-Cable-GA-Twin-Plug+2185)
From my limited knowledge, this kind of thing (available from many other pilot supplies retailers too) is simply a 6.35mm stereo plug extension with a 3.5mm plug extension connected in parallel, right? So I'm also assuming, as the 6.35mm is fairly standard/common, I don't have to look in a pilot shop for this kind of adaptor.
Secondly, is the issue of signal levels. I'm guessing the voltage used to drive beefy aviation headsets is a lot higher than that the camera will have been designed for? I did read (in my other thread) that some trial and error would be involved in solving this one, but I was wondering if there is a more concrete way to do it. Maybe matching impedance figures (again, totaly newbie here)?
Thirdly, and this is the one I'm totally clueless about, is the issue of a DC power source being present on some aircraft intercoms. This is referenced in the item description here:
AIRCRAFT INTERCOM RECORDING CABLE from Aircraft Spruce (http://www.aircraftspruce.com/catalog/avpages/recordingCable.php)
It says that the DC supply can, at best, cause a high pitched squeal on the recording, or damage the recorder if the voltage is high enough. However, from looking here:
TRS connector - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/TRS_connector#Aircraft_headsets)
It seems the DC power supply, if needed, will only connect to the microphone (through the often unassigned tip on the TRS connector), and not to the headphones (with sleeve being common ground, and tip/ring being two audio channels). And as I understand it, the camera would be connected to the intercom's audio output (which connects to the headphones, and therefore without DC power supply), not to the microphone input (where there would be a DC power supply connected to the tip of a TRS connector inserted there).
So how is it that the possible DC power supply is at all relevant to recording to a camera? Am I right in saying that aircraftspruce have built in a useless feature, or have I (probably more likely) totally confused myself?
I'd massively appreciate any feedback on these.
Also, I understand I had started another thread on cockpit cameras, but with the specificty of these questions I thought it might be useful to start a new thread.
Thanks!
Odai.