Video8 Tapes With Choppy Audio but Good Video

[bob73]

Hi,

I'm trying to play some Video8 tapes someone gave me, but I'm having issues with the audio. On a test tape and some of the ones I got, the audio is totally fine, but on the other ones, it's very choppy or completely gone. I have adjusted the tape guides with the help of an oscilloscope to obtain a good video signal, but that doesn't help the audio. With the good tapes, I can adjust the tape guides relatively far until the audio starts dropping out, but with the bad tapes, it seems I need to have them set at exactly the right position to get anything at all (but the video signal is still fine within a fairly large range of guide positions). Even after messing around with the guides a lot, I never managed to get proper audio, it was always extremely choppy.

My question is whether there is some possibility that the audio tracks on the tapes are damaged even though the video tracks are still perfectly fine. I haven't seen any shedding on any of the tapes. Or were there possibly some camcorders that recorded the audio in a weird way that can't be played properly by others? My playback device is a Sony CCD-V900E, but I also tested at least one of the tapes on a Sony CCD-V50E (although I accidentally broke that one, so I can't use it for testing anymore). I also played one tape on a Sony CCD-TRV707E, but I couldn't perform proper tests there because the gear on the takeup reel broke and I don't have a replacement yet. As far as I know, the tapes were originally recorded using a camcorder produced (or at least sold) by Bauer, but I don't know that for sure, and I also don't know what the model number was.

Thanks in advance for any help.

[dellsam34]

Are the tapes Video8 or Hi8? Some Video8 camcorders can playback Hi8 tapes (with minimal artifacts) but the audio decoding can have locking issues, Can you post an audio sample here?

[bob73]

The tapes are Video8, but I had some Hi8 tapes a while ago that didn't cause any issues (the V900E is a Hi8 camcorder, although it only has a mono audio output; the TRV707E that's currently broken is also Hi8 and has stereo audio output). I attached a sample of the audio (recorded with the V900E), it's really just loud humming, occasionally interrupted by the proper audio. I initially thought that there was a problem with the original camcorder that caused the microphone to constantly be disconnected, until I realized that I can sometimes get at least a bit more of the audio by messing around with the tape guides (it always remains very choppy, but I can sometimes get slightly different parts that weren't audible before). As I already mentioned, I can adjust the tape guides with an oscilloscope connected to the test points, which gives me a good video signal, but the audio is still bad. On the good tapes, I never have these sorts of issues with the audio when I've adjusted the tape guides with an oscilloscope. Maybe there was an issue with the original camcorder that caused just the audio to be damaged so other camcorders have issues tracking it properly?

[timtape]

The two short bands of random noise are each about the same duration of 2 seconds or so. The sample isnt long enough to be sure but they could also be separated by regular longer and equal durations. If it's cyclical and regular it could indicate tape damage or at least mistracking at the record or playback stage. I would check the tape carefully for physical damage, including stretching, seen as frilling of the tape edge.

Tapes recorded at the LP speed (half SP speed) have narrower magnetic tracks so are more vulnerable to these types of dropouts when the scanning heads mistrack at some point in their rotation.

Guide adjusting on these small formats can be tricky to avoid damage to tape and machine. Be very careful. Classic errors are winding the guide up or down way too far so as to damage the tape, and accidentally contacting the fast rotating head drum with the metal tip of the adjuster. Concentration, the correct tool and a very steady hand help. Peaking on the video RF signal may not coincide with the peak in the audio signal. You may need to try adjusting for best audio in a separate capture.

[bob73]

Sorry, I should have attached a longer sample. What you're referring to as "random noise" is actually the proper audio, it's just a recording from outside where there isn't much except for wind. I attached a longer sample from another tape now which shows that there isn't really anything cyclical/regular about it. Physical damage also doesn't really explain the issue because it occurs on multiple tapes for the entire duration of the tape (and I can't see any physical damage).

I did find one tape that has one long recording at the beginning and then another short one afterwards (from different events, but as far as I know, the recording dates shouldn't be too far apart). The audio in the first recording is fine, but the second recording is the same as the other tapes with audio issues. This seems to confirm that it really was an issue with the camcorder used for recording since tape damage due to age would have affected both recordings. I'm still wondering what sort of issue the camcorder could have had since the audio does seem to be present, it just isn't being tracked properly.

How would I go about adjusting for best audio? If I understand correctly, Video8 has both the audio and video RF in the same signal, so there's only one test point, and I wouldn't really know how to distinguish between audio and video there.

And yeah, I've learned my lessen about using the correct tools for adjusting the guides. I already destroyed one video head when I didn't have a proper tool yet, but luckily it wasn't a valuable camcorder, so not much was lost.

[timtape]

Fair enough. I dont know what else to suggest except to try the tapes on another known excellent camcorder/deck and possibly carefully adjusting guides for the AFM audio. Early Video 8 recordings were in AFM mono, later ones could be in AFM stereo. Some Video 8 even recorded digital PCM audio. I'm not sure if the AFM stereo recordings were compatible with AFM mono playback. Perhaps try a good Digital 8 camera, one of the models which can play back all these audio formats.

[dellsam34]

Yes I second that, A D8 camcorder with analog playback capability may solve your problem or gets you better results assuming the tapes are not recorded incorrectly to begin with.

[bob73]

Thanks for the suggestions. I don't know if I'll be able to get a Digital 8 camcorder in the near future, but I'll definitely keep it in the back of my mind. I might be getting another regular Video8 camcorder soon, though, so I can at least see if that changes anything. For now, I'll just finish capturing the tapes even with bad audio, so at least the video is preserved.