I think it's the tape, but....
 

I was out shooting today for someone and we got this great, hilarious impromptu moment. I did hear audio on it upon playback. But later, everything from this point forward had both audio tracks dropped out. I had two mics - one wireless, one camera mic for backup. So it wasn't the mics.

I"m guessing it's the tape. I played it back in the camera and heard the audio once. Then, I played it for someone nearby and there were audio problems . We thought it was the headphone. At one point I tucked it in my case quickly without looking, and it was very close to a spare camera battery when I opened it later. There was so much happening, I don't recall if that happened before or after I heard the audio problem since I got it out several times to put it back in the camera to show various people.

When I went to capture it in, both from a deck and from my camera directly, I got capture errors. At one point I was able to capture in some video but still no audio.

The audio appears to be working now and I have never had a problem before.

It's probably the tape, which was unfortunately, brand new.

Here's my question:
1. If it was near the battery by mistake, could that have caused it to erase? (But would that cause a capture error?)
2. Could it be anything in my camera audio system that could have caused the problem?
3. This also makes me nervous because I keep my tapes and batteries all in the camera bag. Is that a bad idea.

Proximity of the tape to a battery should have no effect whatsoever. Tapes can be effected by proximity to a strong magnetic field but a battery is not surrounded with a magnetic field nor does it, by itself, emit or create one. Magnetic fields are created by an electric current flowing, not the mere presence of voltage.

With Steve on the battery-next-to-tapes concern.

It could be bad tape, but, the most likely culprit is a head clog. How long has it been since the heads were cleaned on the camcorder or deck? Tape can be a medium for transferring gunk from one to the other.

Before totally giving up on that recording, I'd clean both sets of heads and try again. Also worth seeing if you can pull the audio off via analog output from the camcorder's line out or headphone out.

Hmmm. Okay. So it wasn't the camera battery or the Duracells for the mic then.
I thought that was it because when I opened the case, the tape (out of its case) had fallen into the cubby with the spare battery and was pushed up against it. And the audio portion that was missing was in the same place that the tape was rewound to.
What are the other possible causes?
If the tape itself was defective, would it have recorded the sound in the first place? Have you guys ever heard of two tracks of audio just... disappearing? I suppose it's possible.
Could there be a system issue in my PD170?
I can hear little flashes of sound on the tape in that area, but mostly silence.

Thanks.
Okay, I can clean the heads. That's a good suggestion because it is past due anyway. Maybe a dirty head caused the issue.
I hardly ever clean my heads on the camera because I was under the impression it wears down your heads to use the cleaner tape. How often should one do that?
It plays other audio fine from that tape and others. I can play and capture from the deck. and the camera. Same tape. Weird. Just that segment is missing, and a few problems right before. Someone is talking, and his audio fades out suddenly at the end.
I was not able to hear anything on the headphone output. Initially, yes, but then it disappeared. It was outside and there was background noise, and the headsets were hard to hear, but I'm sure I did hear audio there. Unless I"m losing my mind. I didn't listen closely because we were passing it around but I did hear something. Then within a few minutes, there wasn't any. I played it for someone, and she couldn't hear it. It was gone. We thought it was the headphone.

The tape capture error was strange, too.

I'll try to do the analog output. Thanks.