Jh-110B - MCi JH-110 Series User Manual

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JH-110B 1.2.1
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JH-110B-14
1.2.2
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Page 1-4
The JH-110B, shown in Figure 1-3, is the standard
model three speed playback and record tape
transport. Full width 1/4 inch, two track 1/4 inch,
and four track 1/2 inch tape versions are available.
All versions can use 3 inch to 10-1/2 inch metal or
plastic reels. A torque limit switch lowers the star ­
ting torque of the reel motors for small reels or for
delicate tapes.
Two servo controlled de motors regulate the tape
tension, keeping it constant during all modes of
operation. An infared tape load sensor brakes the
supply and take up reel motors at the end of roll,
when the tape breaks, or when the tape is remov ­
ed from the sensor slot. An Edit switch can
disable the tape tension servo allowing the reels
to be moved by hand without resistance from the
motors. The manual velocity control (MVC)
joystick gives complete control of the tape ' s mo ­
tion and speed from either the stop mode or the
forward/rewind modes.
To facilitate head alignment and maintenance, the
heads are mounted on a precision machined head
bridge assembly. Loosening two hex screws
separates the head bridge from the transport
deck. Removing the head bridge does not affect
the head alignment. Swapping head assemblies
and roller guides quickly converts 1/2 inch tape
machines to 1/4 inch tape.
The JH-110B mounts in the variable profile
cabinet; its dimensions are indicated in Figure
1-1. Specifications for the JH-110B are listed
in Table 1-1.
The JH-110B-14 contains all the features of the
JH-110B plus the capability of mounting 14 inch
reels. Three torque selection switches adjust the
reel motor torque for different size and weight
reels. The JH-110B-14 also mounts in the variable
profile cabinet.
Specifications for the JH-110B-14 are listed in
Table 1-1.
Standard head bridges contain three heads:
reproduce, record/cue and erase. Additional
mounting space is provided for a preview head
which may be ordered as an option. Tape lifters
move the tape away from the heads during the fast
forward and rewind modes to reduce head wear.
During playback and record modes, a ceramic
capstan and pinch roller arrangement controls the
tape speed. A phase locked loop servo system
drives the de capstan motor. The servo locks the
capstan speed to a crystal oscillator reference. A
reference switch can alternatively select a voltage
controlled oscillator (VCO) or an external signal as
the reference for the phase locked loop. The VCO
allows variable capstan speed control for
operating at any speed 20% above or below the
standard speeds. The transport will accept either
a clock frequency (19.2 kHz) or a variable de level
(-5 to +5 volts) as an external reference input.
Available as optional equipment on all the
JH-110B decks is the RTZ III autolocator. The
autolocator returns the tape to the zero position,
or positions the tape at any of four programmable
positions. A LED display displays the tape posi ­
tion in minutes and seconds of actual playback
time, or the tape speed in inches per second.