585

The Type 585 is a 100MHz oscilloscope introduced by Tektronix in 1959 and made through the 1960's. The 585 uses 580-series plug-ins, which look like letter-series and 1-series plug-ins but are electrically different, primarily in the impedance of the signal interface between the plug-in and the scope. The Type 81 adapter allows the use of letter-series and 1-series plug-ins in a 585. The 585 has tunnel diode triggering and, like many Tek scopes, a distributed amplifier for vertical deflection. Unlike other 500-series scopes, the 585 CRT has distributed vertical deflection plates, enabling it to have both high sensitivity and fast risetime. A Type 585A also exists. Several improvements were published for the 585 circuitry. If all of those changes are applied to a 585, it is essentially a 585A.

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  Front view.

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  Trigger circuit.

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  White plastic clip holds tunnel diode for triggering.

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  Inside view shows regulator tubes.

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  Distributed vertical amplifier.