Mysterious noise on audio tape

[Tom41]

Not really sure if it's the right place to post this, but here's something very strange. I got a brand new audio cassette out of its plastic packaging, put it in my recorder, and recorded a radio programme onto it. The programme didn't fill the tape, but the next episode wouldn't fit on that side as well - so I decided to fast forward to the end so I could use side B.

This particular tape recorder has a search function. That is, if it 'hears' a signal on the tape after a long silence while you're fast forwarding, it'll stop there and play the tape.

Shortly before the end of the tape was reached, the recorder stopped forwarding and started playing. I heard a low, wavering buzz coming out of the right speaker for about 8 seconds, then it cut off. Rewinding the tape a bit, I discovered that the noise was actually on the tape itself, not from the equipment.

This tape is brand new and has never been recorded (or even played) before, except for that radio programme that used up part of one side. The area with the buzz had never been recorded before!

Do factories sometimes put signals onto obscure areas of the tape for testing purposes, before sending them out to shops? If it hadn't been for the search function of my tape recorder, I never would have noticed and probably would have recorded over it later on!

Here's a recording of the sound, if you're interested:
http://tomsonic.dyndns.org/temp/tapenoise.MP3

[Harvey]

Re: Mysterious noise on audio tape

You can often hear a similar noise to yours at the end of side one on pre-recorded tapes, and its a marker used to tell the splicing machines were to cut the tape.

Not sure why that would be on a blank tape though, as its simple to measure the amount of tape on each spool to know where to cut it.

[Junk Parts]

Re: Mysterious noise on audio tape

Many years ago when I still used tape I found and odd one too. It was from TDK. The tape was brand new and still in its wrapper. I put it in the deck just to see what kind of background noise was on a new tape. It didn't have "noise" on the A side at all. It was recorded end to end with classical music! I never figured this one out. I think that maybe it was used as a QC test tape or someone was playing a joke. Why would they put a test tape back on the production line anyway?

[tazwegion]

Re: Mysterious noise on audio tape

Oh how disappointing, I clicked on the thread hoping it would be something relating to EVP

FWIW I've purchased audio cassettes (back before CD's) and found a slight trace of something other than the recorded album at the end of side A

[kc8adu]

Re: Mysterious noise on audio tape

if i were to pull such a prank i would have recorded some record backwards or something.iirc it was called backmasking.