The TapeChek Model 4100 Betacam SP Cassette Cleaner/Evaluator is a professional unit designed for high-speed processing of large and small Betacam and Betacam SP (metal) cassettes. It operates at 25 times NTSC play speed, which translates to approximately 120 inches per second. The machine is built to high standards of quality and performance, with a focus on gentle tape handling and effective cleaning and evaluation.

Function Description

The TapeChek 4100 performs two primary functions: cleaning and defect detection.

Cleaning: The machine utilizes two sapphire burnishing posts and three vacuum-assisted cleaning tissue stations. The burnishers thoroughly polish the tape in both forward and reverse directions. Two cleaning tissues are positioned on the oxide (metal) side of the tape, and one on the back side. A vacuum system aids in transferring loose debris, dust, and surface contaminants from the videotape into the cleaning tissue, significantly reducing dropouts. Older, more heavily used tapes typically show even greater dropout removal. Automatic tissue advance is implemented in both forward and rewind modes.

Defect Detection: The TapeChek 4100 incorporates a highly sensitive optical defect detection system that does not alter or affect pre-recorded tapes. A CCD (charge-coupled device) sensor inspects the videotape for physical damage such as wrinkles, creases, and edge damage. Unlike other systems, the CCD detector is particularly sensitive to longitudinal creases, a common form of tape damage. The system features 64 elements grouped into three channels: Upper, Center, and Lower. A defect may appear in one or multiple channels, but a crease across the tape is counted as a single defect in the total. Instead of counting individual light fluctuations, the machine counts the number of seconds of videotape containing defects, providing a more meaningful defect report.

Automatic Operation: After a cassette is inserted, the operator typically presses the AUTO switch to initiate an automatic evaluating and cleaning cycle. The tape runs forward to its end, then gently stops and automatically reverses. Defect inspection occurs during the reverse cycle, while cleaning and polishing happen in both forward and reverse modes. Upon completion of the automatic cycle, the machine ejects the tape. An optional printer can provide a printed report of the tape inspection.

Erase Options (Optional): Two erase options are available: one for oxide videotape and another for oxide and metal Betacam videotape. The full width of the videotape is erased when this function is selected. Cassettes with activated erase protection tabs will not be erased, and the display will indicate "Erase Protected."

Important Technical Specifications

Tape Speed: 25 times NTSC Betacam tape speed (approximately 120 ips).
Spindle Drive: Capstanless dual-motor spindle drive.
Tape Handling: Metallic leader sensing system and tape accumulators to prevent excess tape tension and ensure gentle handling.
Monitoring: Tape speed and tension are constantly monitored by microprocessor electronics.
Cassette Detection: Infra-red detection systems for cassette size and loading.
Display: LCD display (2 lines by 16 characters) for operator messages and tape data, with adjustable backlight control.
Indicators: Three LED "Tape Condition" indicators ("A," "B," "C") based on the number of defects.
Input: Tape data input keys and numeric keypad.
Burnishing Stations: Two sapphire burnishing stations.
Cleaning Systems: Three vacuum-assisted cleaning systems.
Defect Detection: Optical defect sensing system with CCD line array, detecting longitudinal and transverse creases, wrinkles, and other physical defects. Three-channel system identifies damaged tape areas.
Power: 117 VAC, 3 Amp., 60 Hz. (Standard); 220, 240 VAC; 50Hz. (Special Order).
Dimensions: W x 13" H x 20" D.
Weight: (Not specified in provided text, but listed as "pounds.")

Usage Features

Switches/Displays: The machine features a back-lighted LCD display for various messages and data. Three keyboards or "switch clusters" are on the front panel. The upper cluster controls tape transport functions (Stop, Automatic, Forward, Reverse, etc.) and includes the main power switch.

Tape Condition Indicators: The right-hand keyboard displays "A," "B," and "C" tape condition lights. Factory settings define "A" for 0-2 defects, "B" for 3-9 defects, and "C" for 10 or more defects. These values can be adjusted by the operator using the SET-UP key.

Smart Electronics: The TapeChek 4100 is fully automatic and microprocessor-controlled. It uses sensors to detect cassette size, erase protection tabs, and other machine functions. The POWER switch is under microprocessor control; if turned off with a cassette inside, the machine will eject the cassette before powering down. The system monitors tape tension and speed continuously. Incorrectly inserted cassettes are automatically ejected. A "cleaning tissue exhausted" message will appear if a tissue needs replacement.

Transport Panel Switches:

POWER: Turns the machine ON/OFF. If a cassette is loaded when powering off, it will eject first.
EJECT: Initiates the eject sequence.
STOP: Stops tape movement in forward or rewind, and ejects tape if in Erase mode.
AUTO: Initiates the automatic inspection and cleaning cycle (forward to end, rewind to beginning, then eject).

Membrane Keyboards (Right-hand keypad under LCD Display):

ERASE: Initiates the optional erase function (requires sequence: ERASE, AUTO, ERASE within 3 seconds).
RESET: Clears all defect data, tape information, Tape #, and Operator # from memory. Date is retained until power off.
CLEAR: Clears incorrect data during entry (Date, Operator #, Tape #).
DISPLAY: Cycles through various information displays on the LCD.

Data Entry Keys (Left-hand key panel):

"0-9" KEYS: Numeric keypad for entering Date, Tape #, etc.
TAPE #: Inputs the cassette number (up to 8 digits).
DATE: Enters the date of cleaning/evaluation (6 digits).
OPER #: Enters the operator number (4 digits).
SET-UP: Alters defect values for "A," "B," and "C" tape condition lights. Also used for diagnostic displays (after entering six 9's in the date).
"X": Sequences through defect locations in machine memory when in "Defect Location" mode.
"Y": Sequences through defect locations in reverse order.

Diagnostic Displays: Built-in diagnostic displays assist service technicians. These include status and warning messages, and coded diagnostic readouts. To access diagnostic displays, enter all 9's in the Date and press SET-UP.

Maintenance Features

General Maintenance: Regular cleaning of machine mechanisms is crucial to prevent problems caused by dust, loose oxide, and debris. Flammable or corrosive solvents should not be used.

Repair/Return Procedure:

Call RTI or a Service Dealer for assistance before attempting repairs. Problems can often be diagnosed over the phone.
Obtain a Return Authorization Number before shipping the unit for factory repair.
For factory repair, the unit must be shipped back in its original carton with original shipping materials to prevent damage.

Mechanical Adjustments:

Tape Path Height: The operating tape path height is 1.145" from the bottom edge of the tape to the top of the transport panel.
Cassette Carrier: The carrier height (up/down) is adjusted by moving its mounting brackets to align with the front panel opening. Left/right position is set by small brackets with black plastic rollers. The carrier floor's front/back position and height in the down position are adjusted by four mounting screws.
Magnetic Heads (Optional): The face of the magnetic heads should be square to the panel. The head should be adjusted for sufficient tape wrap to cover the black area of its face. The tape angle entering and leaving the head should be approximately equal.
Tension Sensor: The tension sensor arm and pin must be perpendicular to the transport panel. In diagnostic mode, the tension sensor readout should be "00" or "01" at rest. The spring should be adjusted for slight pressure at rest and 45 grams of force at mid-travel. Squareness is adjusted with washers.
Threading Arms: Spring-loaded arm wheels should lightly press against the transport panel. The rear wheel may lift slightly when tape is threaded.
Threading Arm Rollers: The metal blocks holding the rollers should be close to perpendicular to the transport panel. Roller angle is adjusted by tilting the pulley mounting block.
Threading Arm Switches: "In" and "out" microswitches should activate approximately 3/16" before the arm reaches its limit positions.
Tape Backup Support Block: The black support block with sapphire rods must be square to the transport panel (90°). This is adjusted by adding or removing shim washers from the pivot bracket of the moveable cleaner assembly.
Cassette Height: Determined by six fixed hexagonal support posts. Cassettes must be in contact with these posts, not the carrier floor.
Spindle Height: Spindles should be at .990 inches above the transport panel (plus/minus .004 inches).
Cassette Plunger Sensors: Five plunger-type microswitches should activate approximately 1/32" before the cassette rests on its support post. Plungers should move freely and not be lubricated.
Spindle Movers: Spindles move via a gear motor and cam. Linkage should be straight. Timing belt may need adjustment.
Carrier Lift Assembly: The carrier moves via a gear motor and linkage. Optical sensors on the back edge of the carrier floor control "up" and "down" positions.
Threading Arm Guide Plates: Guide plates should be within .005" of the ball bearing wheels. Regular cleaning of the panel and wheels prevents stickiness.
Cleaner Lift Motor Assembly: The movable cleaner assembly is moved by a gear motor and wire rope linkage. When upright, it should stretch the spring for approximately 1 lb. pressure against the transport panel. The lift motor bracket adjusts spring stretch and engagement force.
Tape Burnisher System: Sapphire burnisher posts should be checked weekly for nicks, cracks, or imperfections. Replace defective burnishers immediately to prevent severe tape damage.

Circuit Board Replacement:

Safety: Disconnect power before removing or replacing any circuit board or wiring.
Connectors: Remove connectors by pulling on the shell, not the wires. Connectors are often keyed or color-coded.
Front Panel Circuit Boards:
- Machine Transport keyboard: Mounted with six screws into metal standoffs.
- Membrane switch keyboards: Fastened with four nuts, with "H" shaped metal supports. Ensure "H" support aligns with insulating mylar strip to prevent short circuits. Do not overtighten elastic stopnuts.
Main Circuit Boards (in cabinet base):
- Microprocessor Board: Held by four screws into hex standoffs. Be careful not to pinch wires underneath.
- Power Board/Printer Board Assembly: Power Board held by six screws into standoffs. Printer Interface Board held by four nuts.
Circuit Boards Below Panel:
- Erase Board: Has RCA phono and Amp connectors, held by two 10/32 screws.
- Sensor Board: Contains leader sensor circuits and wiring for other sensors/microswitches. Mounted to reinforcing rib. Note which 4-pin red connectors go to spindle motor tachs before unplugging.
Circuit Boards Above Panel:
- Tach wheel circuit board: Mounted with three screws. One screw adjusts tach wheel tilt for tape path alignment. Note screw revolutions and spring washer orientation before removal for accurate reinstallation.

Support: RTI maintains a staff of service technicians and qualified service dealers. Contact RTI or your dealer for problems not addressed in the manual.

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