434
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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Links
Documents Referencing 434
Document | Class | Title | Authors | Year | Links |
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Tekscope 1971 V3 N6 Nov 1971.pdf | Article | New Products | 1971 | 211 • 434 • 4610 | |
Tekscope 1972 V4 N5 Sep 1972.pdf | Article | Servicing the 432/434 Oscilloscopes | Ken Matheson | 1972 | 432 • 434 |
Patents that may apply to 434
Page | Title | Inventors | Filing date | Grant date | Links |
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Patent US 3562464A | Cam actuated switch having movable and fixed contacts on circuit board | Howard Vollum • Willem H Verhoef • Tony Sprando | 1968-10-07 | 1971-02-09 | Cam switches • 2701 • 2703 • 432 • 434 • 465 • 475 • 5A38 • 5A45 • 7A15 • 7A16A • 7A18 • 7A19 • 7A24 • 7A26 • 7B10 • 7B15 • 7B50 • 7B51 • 7B52 • 7B53A • 7B50A • 7B70 • 7B71 • 7B80 • 7B85 • 7B87 • 7B92 • 7B92A • 7D01 • 7D12 • 7D15 • 7J20 • 7S12 • 7T11 • 7T11A |
Prices
Year | 1972 | 1973 | 1976 | 1980 |
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Catalog Price | $2,150 | $2,150 | $2,850 | $3,800 |
In 2023 Dollars | $15,800 | $14,900 | $15,400 | $14,200 |
Internals
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.
Pictures
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side connections
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