7
18 FPS home movies, sound or silent. The Pro speed refers to 24 FPS film that was shot by
cameramen with commercial applications in mind.
Note that you will need to also change the setting of the external harmonizer or pitch
shifter, to suit the different running speed. See the Installation section above.
Other Information
The TVT-S8S has a “Mechanism Hours” timer to measure how long the main drive
motor and the mechanism have been running. This only advances in the Forward and Reverse
modes. The count is remembered without need for batteries when the unit is turned off. A time
interval for servicing the drive motor, magnetic head and mechanism has not yet been
established.
Cleaning the sound parts:
If the audio has a muffled quality, there may be a dirt buildup on the magnetic head. To
reach it, remove the sound cover. To clean, push down and hold the “Push” autoloading lever to
raise the black plastic pressure pad from the head, then clean the head with a cotton swab that
has been moistened with a mild solvent such as isopropyl alcohol.
A dirt or oil buildup on the rubber roller can cause “wows” in the sound. To clean it,
give it a spin and lightly apply the cotton swab and solvent while it is turning by flywheel
action.
If cleaning the head does not cure muffled audio from a sound film that is known to be
good, the head may need adjusting or replacement.
Service adjustments:
• After long use, the white balance of the LED and camera module could change. To reset the
white balance, turn to “Still” and “Peak Auto” without film but with a 0.7ND neutral filter in
the light path that includes a small amount of cyan and blue filtering. Observe the C output on
an oscilloscope or waveform monitor and adjust the two left-hand pots on the back of the
Camera module for minimum color subcarrier. Be very careful when adjusting these tiny and
delicate pots so they are not damaged or torn loose.
• Automatic exposure setting should be quite stable. Current optimum factory setting is .90
volts p-p with no film in the gate. Average film will then reach about 100 IRE while “all white”
overexposed film will peak around 85 IRE. The “Average” setting is for .70 volts with no film.
Voltage readings are peak to peak, and will be double if measuring an unterminated output.
• Focus, centering and magnification are factory set and locked in place, and should not be
disturbed. A focus jig is available from TCS for re-setting these. Do not disturb the sound head
adjustments.
• In case of odd symptoms, first check the output voltage of the switching power supply
modules. These should be +12, —12 and +24 volts DC, ±5%. The voltage should change little
no matter what settings are made to the operating controls. The 24 volt supply may sag
momentarily while the drive motor starts running.
• If dust accumulates on the optics it should be removed with a clean camel’s hair brush or air
blower. Fingerprints must be removed immediately with lens cleaner and lens tissue, following
the instructions included with them. There should be no need to open the light source module.
• After long use, if the fixed plastic film guides show excess wear, they can be loosened, rotated
