Atec Tektronix-1502 - Manual (Page 10)

TM 9-4935-601-14-3&P
SPECIFICATION
General Information
The Tektronix 1502 is a portable Time Domain Reflectometer that uses pulses to test cables and provides a
visual display of cable faults. The test pulses are transmitted via the CABLE output jack. Reflections are
received at the same jack and displayed on the Cathode-Ray Tube (crt).
NOTE
All distances are shown in feet followed by metres in parenthesis. Metric units
are not direct conversions from the measurements shown in feet, but represent
the calibrated ranges of the metric option 1502.
Calibrated distance controls allow an operator to examine up to 100 feet (25 metres) of cable with segments as
small as 1 foot (25 cm) displayed horizontally across the 10-division crt screen. Low-loss cables as long as
2000 feet (500 metres) may be examined at 100 feet (25 metres) per division or 200 feet (50 metres) per
division. The horizontal crt scale is calibrated directly in distance units from 0.1 foot (2.5 cm) per division to
200 feet (50 metres) per division in a 1-2-5 sequence (1-2.5-5 sequence).
A 3-digit, direct reading dial indicates the distance to any cable discontinuity when the dial is used to
horizontally position the discontinuity's reflection to a crt reference line.
Vertical (Y-axis) deflection of the crt beam is proportional to the amplitude of the reflected signal plus the
incident step. The vertical scale is calibrated in units of rho (p) of the transmitted pulse amplitude. For a
definition of rho, refer to section 2 of this manual. The sensitivity scale can be selected in 7 calibrated steps
from 5 mp/div to 500 mp/div.
The transmitted pulse is a step-signal having an amplitude of approximately 225 mV. The risetime of the pulse
generator and the equivalent bandwidth of the deflection circuits provide a system reflected risetime of 140 ps
or less.
The 1502 plug-in compartment will accept either the X-Y OUTPUT MODULE or the TEKTRONIX Y-T Chart
Recorder. The X-Y OUTPUT MODULE is a standard accessory for the 1502 and provides an interface for an
X-Y recorder. The TEKTRONIX Y-T Chart Recorder is an optional accessory. This recorder uses a heated
stylus to record on 4 cm wide, heat-sensitive chart paper. The chart recording length represents the entire crt
screen and is controlled by the 1502.
The 1502 is a ruggedized portable instrument that can be used in the field as well as in the laboratory. The
requirements for a Type III, Class 3, Style A instrument as specified in MIL-T-28800 were used as a guideline
for the environmental specifications. The 1502 has a ruggedized case that provides protection when the
instrument is stored in exposed areas. When the instrument is not being used, the accessories, including the
Operators manual, may be packed in the instrument cover and latched tightly on the front of the instrument.
Table 1-1 indicates which accessories may be placed in the cover of the 1502.
The characteristics given in Table 1-2 apply over an ambient temperature range from -15
°
C to +55
°
C after the
instrument has been calibrated at +25
°
C, ±5°C. Under these conditions, the 1502 will perform to the
requirements given in the Performance Check section of this manual.
Table 1-1.
1502 ACCESSORIES
Accessories stored in the 1502 cover
Accessory Tektronix Part Number
1 50
Ω
BNC Terminator 011-0123-00
1 Precision 50 Ω Cable 012-0482-00
1 Viewing Hood 016-0297-00
1 Operators Manual 070-1790-00
1 BNC Connector, Female-to-
Female
103-0028-00
2 Replacement Fuses (for
front panel)
For 115 V ac
Operation
159-0113-00
or
For 230 V ac
Operation (Option 6)
159-0029-00
1 Power Cord 161-0066-00
1 Filter, Mesh (crt) 378-0055-00
Accessories not stored in the 1502 cover
1 TDR Slide Rule 003-0700-00
1 X-Y Output Module 016-0606-00
1 Instruction Manual 070-1792-01
REV D JAN 1981
1-1