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audio distortion while taking video

Posted: Thu Aug 09, 2012 9:53 am
by painless
Ok, this is for you electrical gurus. That means you CJ!

Seeing the GoPro at OSH this year, I figured I should mess around with my Drift HD170 POV camera I have a bit more. I have an attenuating(sp?) chord to connect from the panel to the camera to record cockpit as well as radio communications. I have a PS Engineering PMA4000 intercom, into which I run my Icom AC200 radio.

I find that I need to turn the volume way down on the Pax side, which the chord to the video camera is plugged into to avoid distortion during cockpit communications. That seems to work great.

Radio communication is another thing. Rx from the radio is readable, but "scratchy" for want of a better word. Tx is totally distorted on the video. I have not had occasion where I am unreadable to ATC or other aircraft, however.

So what gives? Here are a few thoughts I have from doing some surfing. 1) Mic gain and/or sidetone needs to be adjusted in the Icom. 2)Mic from headset (David Clarks) needs to be rotated around to get the noise cancelling surface facing my mouth. Anyone ever heard of this?? 3)Need to check antenna coax connector security. 4)Different headseat??

Let me know what you think. Its a bit frustrating, as the intercom recording is clear as a bell. :bang:

Posted: Thu Aug 09, 2012 1:16 pm
by cbkillion
Do passengers or you experience audio difficulties in the headsets as well or is it only evident upon video playback?

Posted: Thu Aug 09, 2012 1:41 pm
by painless
Just on playback. I notice a different "tone" when tx'ing on the radio however. A bit more "scratchy".... That's why I am wondering if I need to adjust my mic gain and/or sidetone. I dont' want to mess with the radio if it is not the culprit, however.

Posted: Thu Aug 09, 2012 4:56 pm
by bullojm1
Hey Jeff,

I can't picture how you are exactly interfacing your camera into the audio....do you have a pic or a product?

I saw this on ACS's website that looks like it may do the trick for ya:


Image
(http://www.aircraftspruce.com/catalog/p ... dapter.php)

You could mount this inline with the pilots headset?

Posted: Thu Aug 09, 2012 5:12 pm
by painless
Mike, that's basically what I have. Got it from Spruce. I have that plugged into the pax headset jack on the panel. It's supposed to step things down so the input from the headset jack doesn't overwhelm the video camera. Seems to do the job for the intercom, but drops the ball when it comes to recording transmissions. Im thinking I need to turn the mic gain down on the icom.

Posted: Thu Aug 09, 2012 6:58 pm
by bullojm1
Jeff,

Have you put it on the pilot headphone jack inline with your headset? Could be worth a shot!

Posted: Thu Aug 09, 2012 7:24 pm
by painless
Yeah, was thinking I might try that. I'm going to switch out headsets too. Just listened to some test videos, and it's really frustrating to hear how clear the intercom records compared to transmitting. :bang: