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Here is a the belt driven cassette loader that was introduced when the 771B chassis came along. It was first used in the slimline series of Betas. Loaders get lots of action. They do get broken and it usually means the end of the VCRs operation. Loaders can be repaired and the methods used are covered later in the CORRECTIONS AND IMPROVEMENTS section. There are several designs that appeared over the years. This one is operated by a cogged belt that comes from the loading and threading transmission assembly. This interesting method can be seen in the next picture. The drive motor can't be seen here because it is beneath the gear with the belt coming from it. Soon this design was improved and simplified, click on the photo. This newer one has fewer moving parts. With no switches to fail it was more reliable than the one before it. It too is driven by a cogged belt that comes from a transmission. A picture of it is shown next. It is the same principle just a little bit redesigned. The belt here was loose in this picture. Click again and this top view shows how the transmission and loader fit together. Click on the photo. This is the last design loader. It is operated by a separate motor. Operated this way eliminates the need for the belt and loading gear arrangement. The size of the threading gear box was reduced as seen in the inset. There are two other unique design motor driven loaders. These were only used in just a few models. Click on the picture. This type is only used in the SLO-1800 duplicator. It is has a metal framework so it is extra beefy. It also employes a special cassette capture action that helped prevent mis-loads. Click to the next picture. Here the one used in the just SL-2500, SL-2700 and Zenith VR 9775PT. It has two states. One when it does not have a cassette inside, as seen on top. And another when a cassette was inside, seen below. It was the only design to operate in this manner. All these are Sony front loaders. The other Betamakers used similar devices in their VCRs. But they all performed the same function and they all had a way of preventing a second cassette from being inserted. Unfortunately all loaders can get broken or damaged in some way. Their repair is covered in another section. They did have another thing in common. They had to handle the standard Beta cassette designed by Sony. I am concentrating on Sony throughout this refurbishing and repair dialogue because they were the primary maker of Beta VCRs. When you think of Betamax you think of Sony, and I work on their machines more than all the others combined. There will be a brief discussion on the other makers and how they are different at the end of this BETA REFURBISHING discussion. Cassette loaders are mechanical slaves whose only job is to accept a cassette and place it down upon four bosses that are attached (molded) to the frame. Click on the photo. Here are the four bosses, the two forward ones are pointed cones with a ledge around their perimeter, the rearward two are flat. The cones insert into two holes located in the bottom of the cassette. Their location is specific to the Beta format design. When the cassette comes to rest on these, and the two rear flat ones, it is held in position by slight downward pressure. Click on the photo for a close up of the two type of bosses. Click the picture again. After the loader successfully positions the cassette inside the compartment two reels located on the table block (shown here) protrude up into the cassette and drive the spools inside. In the In the picture the main components of the reel block assembly are identified. Notice the reels and tension arm (guide number one). There is a band called the tension regulator belt attached to a lever (inside the circle). When the tension arm swings in an arc it pulls a spring attached to the lever. It in turn tightens the regulator belt, which is attached to the base on the other end. Tape pressure applied to the arm as it passes by loosens or tightens the band. Where the belt rides the reel has a special machined surface that is designed to work with the felt strip inside the band. Together these regulate the back tension on the tape by allowing a regulated amount of slippage. This method is the primary way all Beta VCRs regulate back tension, slippage of the supply reel. Over use the surface starts to degrade. Click on the picture. It gets worn and polished, Tension goes up because the tape applies more pressure to the arm. This affects tracking and increases wear of the path components. Or the reel surface can develop a pattern of waves and ripples. This can cause all kinds of problems in the picture and especially in the audio. Under extreme cases the uneven surface will cause the tension arm to shake and vibrate. This shows up most in normal audio recorded in  , because of the slow tape speed. When the vibration gets real bad the picture start to shake. The example on the left is a worn reel, the one the right is a reconditioned one. The take-up reel can also develop an uneven pattern on it from continued contact with the soft brake. This brake is used as a control and keeps a slight amount of drag on the reel at all times. This done maintain control and prevent spillage during reverse functions. To see the reel table again click on the picture. During refurbishing and repair both the reels have their surfaces renewed or, if the is a major problem, it is replaced. Renewing the reels involves running a rotary brush against the surfaces as the reel is turned. This retrores the correct friction factor. To go on to the next section covering the VIDEO AND AUDIO HARDWARE click here  To go to the other subjects covered in this TAPE HANDLING COMPONENTS section:
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