7A42

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Tektronix 7A42
350 MHz four-channel logic triggered amplifier
7A42 front view

Compatible with 7000-series scopes

Produced from 1984 to 1990

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix 7A42 is a four-channel 350 MHz plug-in for 7000-series scopes.

It was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs.

A fifth trace, "Trigger View", displays the trigger function output or external clock input.

The input V/Div setting can only be seen in the mainframe's readout.

Tektronix recommended the P6131, 300 MHz, 10 MΩ ×10 probe, and the P6230, 1.5 GHz, 450/50 Ω ×10, variable-offset probe for ECL circuits.

The 067-1155-99 calibration fixture is specific to the 7A42.

Key Specifications

Bandwidth 350 MHz
Deflection
  • 0.1 / 0.2 / 0.5 V/Div (TTL mode)
  • 20 / 50 / 100 mV/Div (ECL mode)
  • each direct or through 10:1 probe
Input impedance 1 MΩ // 15 pF or 50 Ω
Max. input voltage
  • at 1 MΩ: 25 V (DC+peak AC) below 36 MHz, down to 3 VAC at 300 MHz
  • at 50 Ω: 5 VRMS during any 1 ms interval
Trigger level
  • −1.27 to +1.28 V (TTL mode) in 10 mV steps
  • −254 mV to +256 mV (ECL mode) in 2 mV steps (or ×10)
Hysteresis 40 mV (TTL), 8 mV (ECL) (or ×10)
Features
  • NiCd battery to preserve front-panel control status
Weight 2.8 kg / 6.2 lb

Internals

The 7A42's functions are controlled by an Intel 8085A microprocessor.

Each of the four input attenuator circuits contains five miniature relays. The bistable relay coils are wired in a 4x5 matrix.

The 7A42 contains its own switch mode PSU, based on an SG3524 controller, that generates +5 V, −2 V and −5 V from the mainframe's ±50 V rails.

There is a NiCd backup battery that allows the unit to retain its last configuration.

See also

Pictures

Internal

Components

Some Parts Used in the 7A42

Part Part Number(s) Class Description Used in
148-0145-00 148-0145-00 Discrete component miniature bi-stable relay actuator 7A42 119-1517-00
155-0038-01 155-0038-00 155-0038-01 Monolithic integrated circuit 5-bit current source D/A converter 7A42 7D13 7D14 7M13 T4005
155-0078-00 155-0078-xx 155-0273-00 155-0274-00 Monolithic integrated circuit broadband amplifier 464 465 466 468 475 475A 475M 485 7834 7844 7854 7904 R7903 R7912 7912AD 7912HB 7104 7A16A 7A16P 7A24 7A26 7A42 067-0587-01 067-0680-00 AM503 PG502 PG508 DC510 DC5010 FG5010
155-0236-00 155-0236-00 Hybrid integrated circuit channel switch 2445 2465 2467 7A42
ICM7218 156-1621-00 156-1622-00 Monolithic integrated circuit 8-digit, 7-segment LED driver 7A42 SG5010
Intel 8085A 156-1088-00 Monolithic integrated circuit 8-bit microprocessor 308 468 4025 7A42 7D02 AFG5101 AFG5102 PFG5105
Intel 8279 156-1535-00 Monolithic integrated circuit keyboard controller 7A42 AFG5101 DM5010 FG5010 PFG5105
SG3524 156-0933-00 156-0933-01 156-1585-00 156-1585-01 Monolithic integrated circuit PWM switch-mode controller 067-1011-00 1502B 1502C 1503B 1503C 7A42 DP100