What Are the Best Tips for Recording on Tape?

Audio tape is a magnetic material. It consists of magnetic powder (iron oxide powder) and tape base (acetate fiber or polyester film, etc.). There are two types of general audio tapes and cassette tapes.

Humans began to imagine and develop audio tapes dating back to 1888. At that time, the American engineer Oberlin Smith suggested using a fiber ribbon containing steel powder to record and play back the sound, but it was suspended due to poor results. After 12 years. Danish physicist Waldmar Polling made the same attempt with a steel wire, but the results were still not ideal and failed. The iron powder coated paper tape was tested, but the paper tape was fragile and easily broken, and the steel tape was not easy to splice. The results also failed.

In 1888, American scientist Smith first proposed the idea and theory of magnetic recording. Ten years later, Danish telephone technician Poole invented the first recorder in human history. In 1932, a German chemical company worked on the improvement of magnetic tapes. The company mixed the black magnetic powder of ferric oxide and the binder together, and coated it on a paper tape so that

Audio tapes consist of a tape base and a magnetic layer. The tape base is the carrier of the magnetic layer, and its quality determines the mechanical properties of the magnetic tape; it is required to be able to withstand large tensile forces without elongation, deformation or fracture. The strap base should be soft enough that it is not strapped

Tape

(1) Recording

Use the hysteresis characteristic of magnetic materials to realize the recording of audio signals. As long as the carrier (such as magnetic tape) coated with hard magnetic material moves at a constant speed in the alternating signal magnetic field generated by the magnetic head, the carrier will move in the direction of movement Correspondingly, the sound information is retained on the carrier in a remanent manner. In other words, the audio signal distributed in time will be converted into the information distributed in space and stored, thereby completing the recording of the audio signal. However, it is known from the hysteresis loop that when a ferromagnetic substance is initially magnetized in a magnetic field, the relationship between the size of the magnetic field and the residual magnetic flux on the magnetic tape due to the inertia of the magnetic domains will cause a non-linear relationship, which will cause the recording process. The residual magnetic signal produces severe non-linear distortion. In order to improve the adverse effects caused by this distortion, a magnetic bias current should be added to the recording head during signal recording, which is called bias magnetic recording. The magnetic head is a device that converts electric energy and magnetic energy during magnetic tape recording. The recording magnetic head is composed of an iron core, a coil winding, and the like. A working gap is left in the front and a gap is left in the back. A non-magnetic material is added to the gap. The working gap width of the recording magnetic head is generally 1 m to 10 m; the rear gap is wider, about 300 m. The role of the rear gap is to prevent saturation of the core and reduce modulation noise and interference.

(2) Silence

To re-record a signal on a tape that has already been recorded, it is necessary to mute the original tape. There are two methods of sound attenuation for magnetic tapes: DC and AC. The basic principle of noise reduction is to add a DC or AC magnetic field to the magnetic tape in order to submerge or eliminate the original residual magnetism. In the recorder, the sound head is used for sound attenuation. Its structure is similar to that of the recording head, but its working gap is wide. In order to have a certain magnetic saturation value when silenced, the silencer head has no back gap.

(3) Replay

The playback process is actually the reverse process of recording. It uses magnetic-electric conversion to restore the residual magnetic information on the magnetic tape to an electrical signal. The device that realizes this conversion is a playback head. The magnetic tape must be run at the same speed as the recording head before playing back the magnetic head for correct playback. In the popular recorder, the same magnetic head is usually used to complete the recording and playback functions, which are called recording and playback heads, and the professional recording and playback heads are separated. The playback magnetic head is also composed of an iron core and a coil winding. There is a working gap in the front. When the magnetic tape passes through this working gap, the residual magnetism on the magnetic tape causes the corresponding output voltage to be generated on the coil of the playback magnetic head. ^[2]

1. Divided by appearance structure

According to the external structure, audio tapes are divided into three types: disc tape, cassette tape and cassette tape.

Reel tapes are wound on plastic or metal reels, used on reel tapes on plastic or metal reels, and used in disc recorders. Manual use of the reels is required. The disc tape has good performance and is generally used in professional and stereo recording.

Cassette tapes are end-to-end endless tapes. There is only one reel, which is used for tape playback or stereo playback in cars. Easy to use.

Cassette tape is currently the most widely used tape. Standard cassettes come with C-45, C-60, C-90, C-120, etc. The recording and playback time is 45, 60, 90, 120 minutes. In addition, there are new types of cassette tapes, large cassette tapes, and small cassette tapes.

2. Divided by magnetic powder material

(1) -

,magnetic tape. The tape base is coated with -material, which is a popular magnetic tape. The word "LN" on the cassette indicates low noise, and its high-frequency characteristics are not good. It is not suitable to record programs with a wide frequency range. Recently, a better-quality "tape" marked with the "LH" symbol appears, meaning low noise and high output, which further improves the frequency characteristics, signal-to-noise ratio, and sensitivity of the tape.

(2)

magnetic tape. Commonly known as chrome belt. It is made of chromium dioxide material, and its magnetic performance is better than

Take it well, it is a medium-to-high-end tape. The disadvantage is that the hardness is large and the magnetic head is easy to wear. In order to take advantage of the performance of the chrome belt, the recorder is equipped with a chrome belt transfer switch.

(3)

-

magnetic tape. It is called chrome iron belt, which is coated with - and magnetic powder successively on the belt base, also called double-layer belt. It utilizes the characteristics of -magnetic powder with good low-frequency characteristics and good high-frequency characteristics of magnetic powder. Phase tiles make up for the shortcomings and get better characteristics. The cassette is marked with FC or FCr.

(4) Co--

magnetic tape. Called cobalt belt, it is doped with cobalt ions in -magnetic powder or coated with a diamond compound on its outer layer to form magnetic powder. Good high-frequency characteristics and high signal-to-noise ratio.

(5) Metal tape. It is a new type of magnetic tape. It uses iron-cobalt-nickel metal powder, which has the largest output, low distortion, good high-frequency characteristics, and is not easy to saturate. Suitable for high density recording. The disadvantage is that general recorders cannot play back. The cassette is marked with Metal and MPT.

3. Divided by special purpose

(1) Cleaning the belt. A special tape used to clean the magnetic head can be used instead of alcohol cleaning. Commonly used, such as C-10 tape.

(2) Audition tape. Programs with rich frequency components and good sound quality are recorded on the tape. Use it to check the sound quality of the recorder and perform subjective listening evaluations. Generally use C-12 tape.

(3) Performance test zone. Standard tape for various performance tests on the recorder. There are magnetic flat band, azimuth band, belt speed jitter test band, frequency response band and so on. ^[3]

1) Users should understand the performance of various audio tapes, so that they can play the effectiveness of various tapes according to various specific situations.

2) During the use of the magnetic tape, the magnetic tape should be protected from severe shock and vibration. Otherwise, the internal mechanism of the tape will be damaged or misalignment will occur: affecting normal operation.

3) When using a tape, it should be based on the type of tape. Correctly use the tape function selector switch in the recorder to make all kinds of audio tapes work optimally.

4) The tape should be wound neatly and properly tightened during the process of running or fast-forwarding and rewinding to prevent the tape from deforming, such as jamming and rolling.

5) When using the tape, be careful not to touch the tape with your hands to prevent the tape from being stained or scratched. ^[3]

The storage of audio tapes has a great impact on the mechanical properties, electro-acoustic performance, and service life of the tapes. For this reason, attention should be paid to the following aspects.

1) After using the tape, put it in the box to prevent dust and other foreign matter from falling into the box. '

2) When storing the tape, coil it neatly and vertically to prevent the tape from deforming.

3) Avoid storing tapes in high temperature, low temperature, and humid environments.

4) The tapes on which the programs are recorded should be stored away from various magnetic fields to prevent the program contents of the tapes from being affected.

5) For programs that have been stored for a long time and have precious contents, the anti-miswiring film on the side of the cassette should be removed. ^[3]