581

The Tektronix 581 is a 100 MHz tube scope similar to the 585, but with simplified trigger and sweep circuitry. Like all 580-series scopes, it uses 580-series plug-ins. It was introduced in 1959.

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100 MHz (85 MHz) oscilloscope Tektronix 581 (early model) Produced from 1959 to 1972 Manuals Tektronix 581 Manual (PDF) Tektronix 581A Manual (PDF) 580 series gain adjustment procedure, in Service Scope 39, Aug 1966 (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The 58x series were the first Tektronix scopes to use distributed deflection plates and the last to use distributed amplifiers for vertical deflection.

The vertical signal path of the 581 is the same as that of the 585. It uses the T581 CRT. Type 581 scopes with serial numbers up to 510 use an all-tube trigger circuit. Starting at serial number 511, the 581 uses tunnel diode triggering.

A Type 581A was introduced later, and it is specified to have a bandwidth of 85 MHz instead of 100 MHz. The somewhat relaxed bandwidth specification improved CRT production yield which had been a problem when the scope was specified to 100 MHz.

Specifications

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Pictures

581

early 581
wrinkle and chrome from early 581
TD trigger instead of 6DJ8 trigger

581A

581A

Schematics

early model 581 trigger using tubes
late model 581 trigger using tunnel diode
581 vertical output amp (distributed amplifier) driving CRT