Tape Guide (Sept. 1980)

Solving Dropout Problems

Q. I have a cassette deck that I use to make recordings for playback on an automobile player. After 40 to 50 playings, some spots of the tapes I use begin to suffer high-frequency dropouts. This is very annoying. I clean the heads on both machines and demagnetize them after every six to eight hours of operation. Is it possible that the cassette tape has worn out?

- Richard Bailey, Lynchburg, Va.

A. The following are factors which might account for your dropout problem: (1) The oxide coating on cassette tape is quite thin compared with open-reel tape; the longer the playing time of the tape, the necessarily thinner is the coating, and the more subject it is to wear. (2) You may have obtained an inferior batch of tape. (3) The tape guide finger may be causing wear. (4) One tape manufacturer may be doing a better job than another in providing an oxide coating that is uniform and resistant to wear, and in pro viding properly lubricated tape. (5) After cleaning the heads, you may not have allowed sufficient drying time; the head cleaner (if a liquid) can dissolve the coating.

Proximity of Speaker Magnets

Q. Because of space limitations I would like to put my cassette deck on top of one of my speakers. Will this cause problems due to the closeness to the speaker magnets?

-Dan Pu banz, Shawano, Wisc.

A. It is extremely unlikely that placing your cassette deck atop your speaker cabinet will cause any problems or harm. A distance of about two or three inches between the speaker magnet and other components is sufficient safeguard. I suggest that you read my article, "Magnetic Shielding," in the April, 1979 issue of Audio, which indicates how little danger is ordinarily presented by speaker magnets, audio power transformers, etc.

Disengagement of Transport

Q. I recently bought a radio and cassette player for my car. This player can be switched off by the ignition. I have read that switching the power off with the cassette player in operating position can cause a flat spot on the pinch roller. I try to remember to shut off the player before turning off the ignition, but this is an irritation. Is this really necessary?

- David Benker, Victoria, Texas.

A. Yes, it is important to disengage the capstan and pinch roller from the tape when the transport is not in motion, otherwise the roller tends to go out of round. However, the roller tends to remember its original shape and to return to it when disengaged or in motion. If you leave the capstan and pinch roller engaged only for a short period when the transport is stopped, probably no permanent harm will be done. However, a permanent flat spot might occur if they are engaged for a long time but not in motion.

Metal Tape and Non-Metal Decks

Q. If a metal tape has been recorded on a metal tape deck, can it be played on a standard deck? Do the electronics of the playback amps have sufficient headroom for the higher level obtained from a metal tape? Can the playback head of a standard deck take the wear and level of metal tape? Can I convert a standard deck to record metal tape?

-Charles Wilson, Wheaton, Ill.

A. For playback, recorded metal tapes are generally compatible with non-metal decks. The playback amps in such decks usually have no problem in accepting the higher level of metal tapes, nor do the playback heads. I have heard nothing authoritative about metal tape being more abrasive than other tapes, but I doubt there is any problem.

It would be only with great difficulty that you could convert your deck so that you can record metal tape. Many changes would be needed, including new record and erase heads, greater output from the bias-erase oscillator, more audio drive current, etc.

(Audio magazine, Sept. 1980; Herman Burstein )

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