After it has been established that Beta can accept a tape without damage it is time for the initial check, and eventual alignment. This is routine and is always done after any component in the path is replaced or repaired. This includes, but is not limited to the shuttle, video drum, video disk or ACE replacement. To start the alignment two test leads from an oscilloscope are plugged onto a test connector located on the head amplifier board as shown above. It is almost always inside a can so as to prevent stray interference. There is a lot of amplification and handling go on here so the signals have to be clean. One lead on the plug is the signal coming out and the other tells the scope the time period (the external trigger). The scope can now measures the events amplitude and shape during this interval. Next we play the tracking section of the copied alignment tape and observe the pattern of the wave generated on the scope by the Beta machine. Click on the photo for the results. Looking now at the photos and illustrations above we interpret the information in the following manner. Top scope image is of a perfectly flat wave indicating the tape path is excellent. If we turn the tracking knob to 60% the pattern will contract and expand equally from a large bar to a smaller one. The graph to the top right of the scope images shows the illustration in the service manual of that waveform, and the allowed tolerances. The middle and bottom scope pictures as well as the illustrations to the right of them show the typical waveforms when the tape path is incorrect. In these cases turning the tracking knob from maximum to minimum would cause the images to reduce as shown. It is not remaining flat like in the top image. A Beta tested and found to produce a waveform such as the second photo would have improper entrance path alignment. When entrance is bad the complete path gets adjusted. A Beta producing a waveform like the lower photo may require only an exit path adjustment. We are going to do a complete alignment in the next steps so let us now move on to the ENTRANCE SIDE ADJUSTMENT, click here. To go back to the previous page click here ©Misterßetamax go to homepage