Maintenance
Anyone who has worked in a video facility knows that one of the biggest maintenance issues is keeping the cables going to the right place. With this design the cabling for the different parts of the system will only need to be disconnected for maintenance on equipment.
Once you minimize the need for re-cabling, the next concern is keeping the playback tape machines workingaccording to the manufacturer's specifications. This is particularly difficult with 1/2" open reel, because replacements for many of the key parts are no longer manufactured. The alternatives are to take good care of the equipment and, if possible, acquire machines which can be cannibalized for parts. Many of the basic parts like rollers and drive belts on 1/2" open reels are still available because they are also used by reel to reel audiotape machines.
BAVC has relied on a book in its library called The Video Guide, by Charles Bensinger (Video-Info Productions, 1979). The Bensinger guide has been an essential reference for working with 1/2" open reel. My understanding of how to clean AV-8650 heads comes from the guide.
Cleaning on open reel decks: heads, tape path and slip rings
To clean the video heads of an AV-8650 you will need lint free cleaning cloth rated for clean-rooms and denatured alcohol. The quality of the cloth and alcohol is much higher than what you can buy at drugstores.
These items are often available at the larger electronics stores.
The power to the machine must be off to clean video heads on the AV 8650. Switch the function lever to REW or FF. If you rotate the supply reel spindle you should see the video heads spin inside the video head drum.
Douse the cloth liberally with alcohol and place it firmly against the video head drum in the heads path. Rotate the supply spindle and let the video head contact the alcohol/cloth as it spins four or five times.
Do not move the cloth as this happens, and apply minimal pressure against the cloth to hold it in the head's path.
The CV-2100 does not spin the heads like the AV-8650. In the case of the CV-2100, you must take off the top of the video head drum; the top is held with two small screws. Manually spin the heads as you hold the alcohol/cloth in place next to the video head drum. Continue this process until you no longer accumulate debris.
The stationary heads, including the audio and control track heads, don't require this much care. They can be rubbed with the alcohol/cloth with some pressure, almost as if you are buffing them.
Carefully inspect the path the tape travels to make sure there is no debris left in the tape path. There are grooves along the bottom of the tape path to guide the tape. If necessary run a toothpick along these grooves to make sure any buildup is removed.
The pinch roller is a rubber wheel in the tape path that grips the tape and helps to pull it along at a steady rate. If this roller gets shiny it will no longer provided the needed traction for the tape path. In this case, the tape could even slip out of the direct tape path and cause playback problems or tape damage.
Inside the video head drum is a spindle on which the video heads rotate.. At the top if this spindle are a number of wires making contact with grooves on the spindle. They are called the slip rings. They carry the video signal to the electronics. After some use the grooves in the spindle can accumulate debris and cause black dropouts in the video signal. To clean these slip rings you must remove the video head drum cover, turn the tape machine on and dowse a swab or clean cloth in alcohol. Put the machine in stand-by and so the video heads turn. Apply the swab or cloth to the slip rings, being sure to access the recesses of the grooves. Continue this process until you no longer accumulate debris.