Simple Digital Voice Recorder

[leadZERO]

I'd like to adapt a simple $60 voice recorder to record my flights. From a little searching on the Internet, it looks like the impedance of the radio is 150-600ohms, but I can't find anything that gives me a figure on what the impedance of the mic jack on the voice recorder would be.

It seems most portable headphones are <75ohms, would that mean the microphone would be that as well?

The product I'm looking at is here: http://www.bestbuy.com/site/olspage...order&lp=3&type=product&cp=1&id=1218061082065

 

[MNForrest]

Radio Shack

Your local Radio Shack will have (or can get) a 1/8" x 3' impedance reducing mono cable for about $7. Split your headphone out, reduce one side to 1/8", and you're all set. You'll have to play with the output levels of your intercom and in-line headphone levels to find the right mix.

ff

 

[leadZERO]

Excellent, that works easier than me having to fashion an impedance matcher.

 

[OneCharlieKilo]

I used a similar digital voice recorder to record data for flight testing (climb / descent rates, note stall speeds, etc) but didn't wire anything into the intercom for this. I bought one of the small microphones on a short cord that plugs into the recorder (less than $10), stick the small microphone inside one of the earcups of my headset, and press the record button. Everything I say into my headset mic is recorded by the recorder mic getting the sidetone.
Works fine, and can put the audio on computer for editing out what you don't need. I do end up with a lot of engine and air noise on the audio recording with this method, so wiring into the intercom may be what you're looking for if you want to eliminate that.

 

[Tony Spicer]

I'd like to adapt a simple $60 voice recorder to record my flights.

Find a DVR that has both a remote mic and can be voice actuated. Here's one:

http://www.officedepot.com/a/products/655885/Olympus-VN-4100-Digital-Voice-Recorder/ $39.99

Go to Radio Shack and get what you need to make a mono cable that has a 1/8 jack on one end and a 1/4 jack on the other. Also get a 1 meg resistor. When making up the cable, stick the 1 meg resistor in the ground side of the cable.

Set the recorder to the voice actuated mode and plug into the copilot headphone jack. On my older Olympus, I found that plugging in the remote mic didn't disconnect the built-in mic. That resulted in the recorder running most of the time due to cockpit noise. The fix was to open the case and snip a wire going to the internal mic.

In use, you talk, it records. You stop talking, it shuts off. Somebody else talks on VHF, it records. If you're in an area where the jabber factor is high, switch to a low-use freq. Or if your intercomm works with the radio off, just do that.

Tony

 

[Jim P]

Contour HD and Audio

I've been trying to figure out this same problem and picked up an Olympus digital voice recorder at the Shack. It produced a digital .dat file that I can download to the desktop for editing. I found that wtih the attenuating 1/8" cable from Radio Shack and a 1/4" adapter, the recording quality is excellent. Now all I have to do run the editing against the video and see what happens.