7A42: Difference between revisions

Revision as of 02:28, 17 July 2021

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 10 MΩ probe, and the P6230 variable-offset 450 Ω probe for ECL circuits.

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

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 or 50 Ω
Max. input voltage	at 1 MΩ: 25 V (DC+peak AC) below 36 MHz, down to 3 V_AC at 300 MHz at 50 Ω: 5 V_RMS 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

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.

@@ Line 23: / Line 23: @@
 Tektronix recommended the [[P6131]] 10 MΩ probe, and the [[P6230]] variable-offset 450 Ω probe for ECL circuits.
+The [[067-1155-99]] calibration fixture is specific to the 7A42.
 {{BeginSpecs}}