TAPE GUIDE (Mar. 1988)

Improper Winding

Q. In record or playback mode, my cassette deck initially does not wind the tape squarely on the cassette's take-up reel; part of the tape extends over the edge of the reel. After about three minutes, the tape begins winding correctly. When the deck is put into fast forward or fast rewind, there is no problem. What causes the faulty winding? How can I correct it?

-Albert C.; Osofsky, Philadelphia, Pa.

A. Some decks have separate motors for the supply and take-up reels. If this is true in your case, it could be that the take-up motor is defective.

Alternatively, it may be that the take up reel does not exert sufficient tension. There is an internal adjustment for this, but it will vary from one make of deck to another, so I cannot advise you more specifically. To know exactly what to do, you will need to consult the service manual for your deck, and you will probably need a gauge to measure torque; otherwise, you may do more harm than good. Unless you are expert in this sort of thing, the adjustment is best left in the hands of a qualified service technician.

Cleaning Frequency

Q. I used to clean my deck after every two hours of operation, using isopropyl alcohol. Even with such frequent cleaning, an oxide "track" was developing on the pinch roller. I considered this normal and ignored it.

About a year ago, at a friend's suggestion, I tried a "rubber rejuvenator," which completely removed the oxide and improved the roller's traction. But when I used it for regular, frequent cleaning, traction became very poor for a while. Therefore, I went back to isopropyl alcohol. Subsequently I tried a professional aerosol cleaner that is a blend of freon TF and isopropyl alcohol. This completely removes the oxide track, and traction remains great. Am I over-cleaning? Is there supposed to be an oxide track on the roller?

-Scott Eric Packard; Los Alamitos, Cal.

A. Yes, I think that you are cleaning too frequently. The usual rule is to clean the heads, capstan, and pres sure roller after approximately eight hours of use. And yes, it is normal for a small amount of oxide to accumulate on the roller, though this will vary with the brand, type, and quality of tape, and perhaps with the deck.

Isopropyl alcohol usually works well and is suitable for cleaning. However, you might want to check with the deck manufacturer as to his recommendation. After cleaning, be sure to allow adequate drying time-at least five minutes, to be safe.

Print-Through Prevention

Q. How can I best prevent or re duce print-through on my tapes?

- Roberta Lindenberg, New York, N.Y.

A. Storing tapes in cool, dry places and keeping them away from magnetic fields help prevent print-through. Fast-winding a tape just before playback also helps, because print-through signals are transient, and their level drops when they are removed from the imprinting field. This is one of the reasons why studio tapes (which are recorded in only one direction) are not rewound after recording, but are left "tail out" on the reel and rewound just before play back. Home tapes, which are recorded both ways, can be wound forward and back before they are played.

It is also probably wise to play or fast-wind each of your tapes at least once or twice a year. This is because taped signals become increasingly difficult to erase with the passage of time.

Presumably, this would apply to the printed-through signal as well as to the desired one; "exercising" the tape periodically might well reduce the printed signal before it has time to "set."

Mechanical Malfunctions

Q. My problem concerns a cassette deck purchased in 1984 but used for only about 20 hours. When I play or record a Type I tape, everything is fine; when I play or record a Type II, I have major problems. The tape gradually speeds up until it is going so fast that you can't hear anything but "chipmunk" sounds, and eventually the tape gets tangled around the capstan.

The authorized service center in my area wants $75 as a bench charge just to look at the deck, which cost me only $140 originally. For sentimental reasons, I would rather not replace the deck.

-Bobby Fox, Rockville, Md.

A. I can't come up with any reason why your deck should exhibit its strange mechanical behavior solely with tapes other than Type I. When switching types, only electronic changes occur in the deck, not mechanical ones. Perhaps some reader can offer counsel.

It appears ridiculous to spend $75 at minimum-to salvage a deck that cost $140. Today, for not much more than $100 at discount stores, you can buy a new cassette deck that is probably at least as good as your present model. I suggest that you save your money by using your deck only with Type I cassettes, and when it eventually goes bad altogether, put your $75 (or more) toward a new deck.

Superior Tape, Reduced Output

Q. When I make a cassette recording with my usual tape, it plays back at the same level that I used in recording, as shown by the deck's meters.

But when I use a superior tape made by the same company, with everything else remaining the same, the playback level is below the recording level. I have tried cleaning the heads, demagnetizing them, and using other cassettes of the superior formulation, but I still get reduced output. What could be the explanation?

-Jeffrey Nachson, Brooklyn, N.Y.

A. Tapes differ in their sensitivity that is, in the amount of signal output for a given amount of signal input. That is why you get different playback readings with different tapes.

There are a number of electromagnetic and physical factors that add up to a good tape. Sensitivity is only one of these factors; others include extended frequency response, low distortion, low modulation noise, high maximum output level for a given amount of distortion (and therefore high signal-to noise ratio), smoothness of the magnetic coating, immunity to oxide shed ding, accuracy of dimensions, immunity to cupping or other warping, and immunity to skewing and squeal. It is quite possible for a superior tape to have lower sensitivity than an inferior tape but to excel in all or most other respects.

(Source: Audio magazine, Mar. 1988, HERMAN BURSTEIN)

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