Table of Contents
Advertisement
General Information
Model 280B
Table 1-2. SPECIFICATIONS (Continued)
Bias and Erase
Frequency
160 kHz
Erase Efficiency
Greater than 75 dB at 1 kHz below 500 nWb/m
Remote Control
Duplicates transport controls, except that ATL
defeat is provided by holding down either of the
fast function buttons.
NOTE: Specifications subject to change without notice or obligation.
1.2 TAPE TRANSPORT
The tape transport handles 0.25-inch (6.35 mm) or
0.50-inch (12.70 mm) magnetic tape on reels up to
11.5 inches (28.2 cm). Tape control functions in
clude tape take-up TENSION (reel-size) switch;
Fast Forward and Fast Reverse, STOP, START,
and Edit pushbuttons; and
a
CAPSTAN High/Low
speed select switch. An automatic tape lifter (ATL)
is provided to minimize tape and head wear during
Fast Forward (FF) and Rewind (FR) modes. For
fast cueing, a manual defeat of the ATL functions
is also provided. The pushbuttons are lighted to in
dicate visually actual transport mode of operation.
1.3 ELECTRONIC ASSEMBLY
The electronic assembly contains: the record/play
back control panel and amplifier assemblies; a regula
tor, bias oscillator, and amplifier prin ted wiring assem
bly (PWA); and a permanently mounted electronics
motherboard assembly. An equalization PWA plugs
into each record/playback amplifier PWA Equaliza
tion is switched automatically when tape .speed is
selected. A RECORD READY switch on the record/
playback control panel allows recording on any or all
channels. Each record/playback control panel con
tains a vu meter that indicates playback or record
levels. One record/playback control assembly is provi
ded for each channel. One regulator, bias oscillator,
and amplifier PWA provides dc voltages and bias sig
nals for one or two channels. An additional bias
Amplifier PWA is used for four-channel systems.
1-4
1.4 HEAD ASSEMBLY
The head assembly contains three head stacks:
erase, record, and playback. Refer to Table 1-1.
1.5 OPTIONAL AND ACCESSORY EQUIPMENT
The following optional and accessory equipment
is available for use with the 280B Series Recorders.
• Remote Control Unit, Figure 1-2: The table
model has a 31-foot long cable with connec
tor P1l1 installed. The panel mount configu
ation includes mating connectors and pin ter
minals for a cable of the desired length up to
50 feet.
• Capstan servo system option: Provides in
creased speed accuracy, less flutter and wow,
and improved frequency response. The servo
system is designed around a printed circuit
motor. A crystal oscillator provides the basic
tape speed reference frequency with an opti
cal tachometer serving as
the functional
reference.
• Varisync Model VS-76: Varies tape speed
from any of the preset speeds (3.75, 7.5, 15
or 30 in/s) by +50% to -25% and can lock
the capstan motor speed to a pre-recorded
control track.
The Varisync accessory can
Advertisement
Chapters
Table of Contents
