HOW THE VCR SOLVED AN UNSOLVABLE PROBLEM

The VHS, a staple of the home movie industry. The VCR, a technological breakthrough that took the world by storm. Together, they ruled over the home movie industry and owned analog video.

But that was years ago. Since then, technology has made leaps and bounds, and the world of digital has taken over, making technology like the VCR a boring, outdated piece of equipment that’s nothing special. Right?

Wrong! The VCR is one of the most interesting, innovative pieces of tech that puts much newer tech to shame. The inside of a VCR is a bundle of parts that work just as cool as they look. So let’s open one up and dive into how exactly the VCR solved an unsolvable problem.

THE SPEED ISSUE

First, let’s break down the main issue that stood in the way of building a videotape player: Speed.

Analog TV signals weren’t made up of tiny pixels, as digital TV signals are today. Instead, they used a high-frequency signal (about 5 million hertz) of continually varying intensity. Magnetic tape recording, due to its structure, has to record at a high frequency. This is why, at the advent of television, TV shows were generally live and not pre-recorded, though machines like kinescopes and telecines could be used as a cumbersome workaround for recording.

But when it comes to magnetic tape, even a pure audio (no video) signal has to move past the tape heads pretty dang quickly. For those 5 million Hz video signals? It would need to travel a lot of feet per second. You could only get about two and a half minutes from a 2,400-foot spool of tape.

But that didn’t stop people from trying.

A DRUMROLL PLEASE…

Ampex, a company based in California, came up with the idea that broke open everything: to have the heads move past the tape, instead of the tape move past the heads.

This idea was revolutionary. Instead of having a single stationary head, Ampex created a quadruplex system that used a rotating drum containing four tape heads. These heads sat perpendicular to the path of the moving two-inch-wide magnetic tape. Then it was the drum, not the tape, that moved at such an incredible speed. Spinning at a rate of 3,600 rpm (rotations per minute), the heads traveled past the tape super quick, which was enough for an acceptable video signal.

This 1950s Ampex machine became a standard for television studios everywhere. But there were three main issues with it: it was the size and weight of a large chest stuffed with electronic parts, it cost $45,000 (which equates to over five hundred thousand dollars today), and it took extensive training to operate.

But all hope was not lost. After the realization that moving tape heads solved the speed issue, consumer video tape players and recorders were developed. JVC, the Victory Company of Japan, wanted to create an affordable, longer-recording, consumer-friendly system, and in 1976, they achieved their goal. The VCR was born, containing a video head system similar to the quadruplex system.

VIDEO CASSETTE TAPE

Earlier machines, like reel-to-reel decks, had to be threaded manually, but that wasn’t the case with the VHS tape. These cassettes are plastic shells that hold magnetic tape wrapped around two spools. If you were to open up your VCR and see beyond the cassette, you’d notice that the VCR pulls out some of the tape from the cassette so it can wrap around the video head drum.

The cassette has cut-outs in the bottom, allowing two spindles to stick up behind the tape. When the cassette is pushed into the VCR, the cassette gets lowered into the machine, and the spindles move toward the back of the machine, pulling the tape past the necessary components.

LET'S GIVE IT UP FOR THE LETTER "M"

The magnetic tape travels in the shape of an “M.” It starts with moving past the erase head; during recording, this head is responsible for removing the signals currently on the tape. Then it wraps around the video head drum (more on this part later). Next, it goes past two more heads, which record the audio and a tracking signal (allowing the VCR to maintain the correct tape speed during playback and to compensate for slight differences between tapes recorded on different machines); these two signals are recorded along the edges of the tape. Finally, the capstan and pinch roller, which squeeze the tape together; the capstan is responsible for pulling the tape through the process.

Cogged spindles are there too, though their job largely comes into play only when the tape is being fast-forwarded or rewound. Otherwise, they’re mostly there to keep the tape taunt.

A VCR’S BEATING HEART

The drum is the beating heart of your VCR. If you take the lid off your video tape machine, you’ll notice it sitting big and bright and shiny. The noise of the video head drum spinning against the tape is the sound you probably even now associate fondly with a VCR. In the US, it spins at a rate of about 1,800 rpm. One revolution is one frame of video. The frame rate for US standard broadcast television is roughly 29.97 frames per second, meaning the head spins nearly 30 times per second.

There is a slit that separates the two halves of the drum, behind which are the minuscule heads. All VCRs have at least two heads. Higher-end VCRs had four or sometimes even six heads, which is said to improve image quality as it can record a more precise signal.

The real beauty of the drum head, however, is its lopsided angle. The first time you see it, you may assume it’s just the way it was designed. But there’s a reason behind the madness.

You see, it doesn’t sit level in the machine due to something called helical scanning. While a tape is running, the head travels diagonally down the surface of the tape. Since video signals need to store so much information, an angled drum (and thus the angled heads in the drum) can contact and process more of the tape surface as the tape moves horizontally.

PRO TIP: If you own a VCR, the drum needs to be cleaned every few months to maintain good picture quality. You can watch the step-by-step process on our YouTube tutorial here.

SUMMARY

While a laser reading data off a spinning disc is cool, it just can’t compete with the ingenuity of a VCR. The invention of the VCR took some serious persistence and thinking outside the box. The effort in getting the tape around a cylinder itself is far more intricate than many digital technologies today. So the next time you look at a VCR, remember just how incredible the technology inside it is.

Thanks for reading! If you’re interested in owning one of these incredible machines, we specialize in refurbishing and selling VCRs. We have everything from hi-fi VCRs to DVD/VHS combo players to VHS to DVD converters to S-VHS systems. You can check out the entire collection here. Have a great day!

https://spencertified.com/collections/refurbished-vcr-vhs-players