VHS tapes, also known as Video Home System videocassette tapes, were popular worldwide for over 30 years as a medium for consumer recording and playback of television shows and movies. Here you will learn how they work, including the encodings used in different parts of the world, and where you can still buy these tapes today.
The Leading Consumer Standard
VHS is a standard for analog recording of video and audio on videocassettes, including the electro-mechanical specifications of the cassette, tape and recording mechanism. It is based on the more expensive, professional-level Video Tape Recorder (VTR) standard but is designed for mass-market consumer equipment.
A competing standard, Betamax (often referred to as “Beta”), was released first but quickly lost most of its North American market share to VHS. The main reason VHS dominated was that VHS tapes could record up to two hours of video on a single cassette, whereas the Betamax recording time was significantly less.
Basic Recording and Playback
Each VHS videocassette includes two spools and a simple plastic mechanism to guide the half-inch magnetic tape and prevent it from coming off the spools as they turn. Similar to an audio cassette, the videocassette mechanism moves the tape past a number of recording or playback heads at a consistent speed in either a forward or reverse direction.
When a VHS cassette is inserted into a videocassette recorder (VCR), the tape moves past a cylindrical spinning drum containing the video recording/playback heads, after passing over an AC signal head, which can erase any previous recording. A fixed head then records or plays back control signals and audio. Each frame of video, which includes two TV picture fields, is represented by one full rotation of the spinning drum.
The control information during a recording marks the start of each video frame as well as the beginning of each recording session. The number of hours of video and audio that can be stored on a single tape depends on many things, including the encoding used and the length of the tape in the cassette. Each tape also includes an optically clear section at the beginning and end, detected by photodiodes in the VCR to stop the drive motor automatically.
Videotapes Are Sensitive
Because the video, audio and control information is stored on a VHS tape magnetically, you need to avoid exposing the tape to magnetic fields. Exposure to magnets or magnetized surfaces – such as metal screwdriver tips, paper clips, refrigerator magnets, audio speakers or motors – can partially erase or damage a video recording.
VHS tapes are also sensitive to direct sunlight, heat and humidity. You should keep a tape in its box or case when you’re not using it, in a relatively dry and cool area. Under the right conditions, mold can form on the tape inside the cassette, degrading the physical and magnetic qualities of the tape and contaminating the VCR heads and rollers when the tape is played. Skin oils, dust and dirt do this also, so don’t expose the inside of the cassette to the outside world.
Videotapes can also stretch and sag easily. The best way to preserve your tape is to fully rewind it after use, don’t leave it in the VCR for long periods of time and store the tape vertically in its case. A VCR mechanism that’s out of alignment can also stretch or scratch a tape, decreasing its life and affecting the video quality.
One Tape, Several Possible Encodings
VHS VCRs in different parts of the world use the same physical VHS tapes, but the signals recorded on the tapes are unique to the particular color encoding method used by the device that recorded them. NTSC, PAL and SECAM are the most common encodings and are generally incompatible with each other. This means that a videotape recorded by a VCR using the NTSC encoding cannot be played back in a VCR that uses PAL encoding, and vice versa, unless the VCR is specifically designed to support multiple encoding types. Some encodings use different tape speeds or head rotation speeds than others, as well as store video, audio and control data in a different manner.
This also applies to commercially duplicated tapes, such as mass-produced movies or TV shows. If you purchase a movie from a vendor in a region that normally uses SECAM encoding, and you try to play it on the VCR you bought in your home country and that uses NTSC encoding, it’s likely that your VCR won’t play the SECAM-encoded movie tape correctly.
PAL is used in most of Western Europe, Asia, the Middle East, Australia, New Zealand and parts of Africa. NTSC is common in North America, most of South America, South Korea, the Philippines and Japan. SECAM is often used in parts of France, Africa, Eastern Europe, Russia and Greece.
How VHS Copy Protection Works
Pre-recorded commercial movie sales and rentals were a huge part of the market for VHS tapes. Consumers and illegal video “pirates” quickly discovered they could copy these tapes just by connecting two VCRs together, with only a slight decrease in video quality. To prevent this from happening, movie distributors developed copy-protection methods that rely on a tape’s ability to record signals that are not within the bounds of the VHS specification. One method causes severe variations in picture brightness during the recorded video, by confusing the recording VCR’s circuitry that automatically adjusts gain and picture levels. Erroneous signals are recorded on the original tape in the intervals between actual video frames and fields. These are ignored by most television sets but affect the circuitry of the VCR being used to record the duplicate tape. Other methods cause the recording VCR to pollute the duplicate tape with incorrect colors or color bars that appear throughout the video. These methods greatly reduced the unauthorized copying of VHS tapes during the analog era of video recording.
Where To Buy VHS Tapes Today
VHS was still popular when DVDs arrived, leading manufacturers to make DVD players that could also play and record VHS cassettes. This helped keep VHS tapes in demand for a few more years. Manufacturers stopped making brand new tape cassettes and VCRs between three and 10 years ago, but many can still be purchased from a variety of sources worldwide.
Brand new blank and commercially pre-recorded tapes, still shrink-wrapped in original unopened packages, can often be purchased online. These are generally available from surplus electronics sellers, online stores and individuals on sites such as eBay, Amazon and online auctions. Some large retailers, such as Walmart and Staples, also stock new blank tapes, though you may need to order them online rather than find them on a store shelf. Some VCRs, tape duplicators and other VHS equipment may also have blank VHS tapes bundled with them for sale.
Used blank or pre-recorded tapes can also be found on Craigslist, at garage sales and thrift stores. Some used book stores may also sell new or used videotapes, especially those that still carry records and audio cassette tapes.
If you have a commercially pre-recorded tape that you no longer want, you can record over it. Locate the square “write-protect” notch in the videocassette case and cover it with a piece of thick tape. You could also tape a small piece of card stock (such as part of an index card) over the notch. Your VCR will detect that the notch is absent and allow you to record over the content. Some pre-recorded tapes may be shorter than you expect, because they include just enough physical tape for the length of the recorded content. For example, a pre-recorded cassette containing a 90-minute movie may have exactly 90 minutes’ worth of tape in the cassette, unlike a new blank tape that has enough to hold 120 minutes (or more) of content.
VHS Lives On
VHS tapes, once the standard for consumer pre-recorded movies and home video, are still available in the digital era if you have the right equipment. They provide significant recording quality and capacity on each videocassette (two or more hours) and are relatively simple and reliable in construction, operation, recording and playback. They are easy to care for and can be re-recorded with new material, even if they contain commercial pre-recorded, copy-protected content such as movies.
VCRs and TVs record and display content unique to the encoding method used (such as NTSC, PAL or SECAM) in the geographic region they were designed for. When you purchase a blank VHS tape, you can record content on it with a VHS VCR of any encoding type. Once the content is recorded, it will only playback on equipment of the same encoding type that it was recorded with (until it is erased and recorded over with something else). This is important if you plan on purchasing pre-recorded videos, such as movies. You need to be sure the pre-recorded tapes you buy were recorded with the same encoding as your VCR, otherwise you won’t be able to watch the tapes. Since these tapes and VCRs are no longer manufactured, and many of today’s sources are individuals or businesses in countries that use encodings other than yours, be sure to find out if the tape’s encoding matches your equipment before you purchase.