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Tektronix 7B70
200 MHz Timebase
Tektronix 7B70

Compatible with 7000-series scopes

Produced from 1969 to 1975

(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 7B70 is a 200 MHz time-base plug-in for 7000-series scopes. It has no delay function.

For delayed-sweep applications, the 7B70 is operated in conjunction with the model 7B71 delaying timebase. The 7B70/7B71 were primarily intended for the 7704 mainframe.

The task of designing the 7B70 was inherited and completed by Murlan Kaufman.

The 7B71/7B70 were superseded by the 7B85/7B80 pair (400 MHz) in 1976.

Key Specifications

Sweep 5 s/Div to 20 ns/Div in 1−2−5 sequence, ×10 magnifier down to 2 ns/Div, variable down to 12.5 s/Div
Excluded portions of sweep None in 7700-series, first 50 ns with magnifier
Trigger sensitivity 0.3 Div (int) or 75 mV (ext) up to 20 MHz, 1.5 Div or 375 mV from 20 MHz to 200 MHz
Trigger coupling DC, AC (>30 Hz), AC HF REJ (30 Hz to 50 kHz), AC LF REJ (>30 kHz)
Trigger input 1 MΩ // 20 pF, max. 500 V DC+peak AC
Jitter less than 1 ns at 150 MHz
Trigger Modes Peak-Peak Auto, Auto, Norm, Single Sweep
External horizontal amplifier 25 mV/Div or 250 mV/Div ranges, variable

X-Y operation

The 7B70 has a dedicated switch to put it in "amplifier mode" for X-Y operation. In this mode, the Trigger Source switch controls the signal source – internal from a vertical plug-in via the trigger path, or external — and the Trigger Coupling switch controls AC vs. DC coupling.

In amplifier mode, gain can be varied using an uncalibrated potentiometer.


Documents Referencing 7B70

Document Class Title Authors Year Links
Tekscope 1969 V1 N5 Oct 1969.pdf Article Introducing the New Generation 1969
Tekscope 1969 V1 N6 Dec 1969.pdf Article A New Logic for Oscilloscope Displays 1969
Tekscope 1974 V6 N4.pdf Article Troubleshooting the 7B70 and 7B71 Time Bases Jim Lawe 1974
Tekscope 1974 V6 N5.pdf Article Understanding oscilloscope trigger controls 1974


The 7B70 contains five 148-0034-00 miniature relays and one 148-0035-00. It also contains one 152-0154-00 and two 152-0125-00 tunnel diodes.



Some Parts Used in the 7B70

Part Part Number(s) Class Description Used in
148-0034-00 148-0034-00 Discrete component miniature DPDT relay 7A11 7A13 7A14 7B70 7B71 7503 7904 7904A
148-0035-00 148-0035-00 Discrete component miniature SPDT relay 7A13 7A14 7B70 7B71
1N3717 152-0381-00 152-0125-00 Discrete component 4.7 mA, 25 pF tunnel diode 1L40 1S1 1S2 11B1 11B2 11B2A 147A 1470 148 21A 22A 3B4 3B5 408 432 434 453 453A 454 466 491 5T3 544 RM544 546 RM546 547 RM547 556 RM556 7B70 7B71 7D11
SMTD995 152-0140-01 Discrete component 10 mA, 8 pF tunnel diode 1S1 1S2 1502 21A 22A 3T5 3T6 475 475A 475M 544 R544 546 RM546 547 RM547 556 R556 581A 585A RM585 7B52 7B53N 7B70 7B71 7D10 7D11 7T11 7T11A R7912 S-51 S-52 TU-5 067-0572-00 067-0572-01 067-0681-00
STD704 152-0125-00 Discrete component 4.7 mA tunnel diode 1L40 1S1 11B1 11B2 11B2A 147 R147 147A R147A 1470 148 R148 148-M 149 R149 149A R149A 21A 22A 3B4 3B5 408 432 434 453 453A 454 464 465 466 491 5T3 544 RM544 546 RM546 547 RM547 556 RM556 7B70 7B71 7D11
TD253 152-0154-00 Discrete component 10 mA, 9 pF germanium tunnel diode 547 7B70