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Tektronix 434
24 MHz analog storage scope
Tek 434

Produced from 1971 to 1984

Manuals – Specifications – Links – Pictures

The Tektronix 434 is an analog CRT storage scope with two independent storage areas on the screen.

It has a bandwidth of 24 MHz and uses a tunnel diode in its trigger circuit. The storage is done in the CRT itself, by trapping charge on a special fine grid of isolated pads behind the phosphor where the electron beam is then blocked or released.

There is a chopped two channel system and the fastest sweep time is 20 ns/div. An option for a tube with higher sensitivity at high writing speeds was available (OPT. 01).

Key Specifications

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The signal passes through rotary cam-operated input attenuators, then passes through an input amplifier that is on a separate small board. The input amplifier contains a JFET source-follower buffer that uses a 2N5911A (Tektronix part number 151-1032-00) biased with a drain current of 12.5 mA and Vgs of –0.26 V. The input amplifier has unity gain, high input impedance, and an output impedance of about 120 Ω. The input amplifier drives a Tek-made differential amplifier chip, part number 155-0050-01.

The original instrument design utilized an all-discrete switching power supply, making this an incredibly light portable scope. Unfortunately, this power supply was extremely difficult to troubleshoot when it went belly-up. At serial number B500000 and later, the design of the supply was simplified to use the same basic circuitry as found in the 7704A using a Tek-manufactured controller chip.

Repair Issues

See → Repairs page.



CRTs used in the 434

Page Part nos Description Designers Used in
T4340 154-0666-10;154-0666-12 storage CRT 434

Custom ICs used in the 434

Page Model Part nos Description Designers Used in
155-0028-00 M018 155-0028-00 155-0028-01 155-0042-00 155-0042-01 155-0042-02 155-0042-03 Miller integrator and delay pickoff Joe Burger 5030 R5030 5031 R5031 1401 1401A 1480 1481 1482 1485 26G1 26G2 26G3 314 335 432 434 4701 5B10N 5B12N 5B31 5B40 5B42 5S14N 7B52 7B53A 7B53N 7L12 7L13 7L14 7L18 7S14 AN/USM-281C RG501
155-0050-01 M065 155-0050-00 155-0050-01 differential vertical preamplifier Bert tenKate 432 434
155-0051-00 155-0051-00 155-0051-00 Z-axis and HV regulator 432 434
155-0067-02 M091B 155-0067-00 155-0067-02 155-0067-03 SMPS controller Joe Burger Gene Andrews 7704A 7834 7844 7854 7904 R7903 7904 7904A 7934 R7912 7912AD 7912HB 7934 7104 R7103 308 434 485 690 P7001