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(Types [[1A5]] and [[1A7]] have an internal jumper that can be cut.) | (Types [[1A5]] and [[1A7]] have an internal jumper that can be cut.) | ||
Early production Type W in a [[556]] mainframe won't | |||
meet spec for overdrive recovery time, because an overdriven W | meet spec for overdrive recovery time, because an overdriven W | ||
passes enough common-mode to the mainframe vertical amp to | passes enough common-mode to the mainframe vertical amp to | ||
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This was also offered as mod kit 040-0447-00. | This was also offered as mod kit 040-0447-00. | ||
Type W was created with a pair of type [[8056]] [[Nuvistor|Nuvistors]] in the front end. In 1971, at serial number 7000, the Nuvistors were replaced by JFETs to reduce drift. Modification kit 040-0590-00 was offered to retrofit existing instruments. | |||
In the letter-series timeline of differential comparators, Type W, [[introduced in 1965]], | In the letter-series timeline of differential comparators, Type W, [[introduced in 1965]], | ||
follows [[Z|Type Z]] and precedes [[1A5|Type 1A5]]. | follows [[Z|Type Z]] and precedes [[1A5|Type 1A5]]. | ||
Revision as of 09:34, 18 June 2021
Template:Plugin Sidebar 2 The Tektronix Type W is a differential comparator plug-in amplifier for 500-series scopes. Its bandwidth varies from 23 MHz to 8 MHz depending on gain. Type W is faster than its Type Z predecessor, and it extends performance in terms of sensitivity, reaching 1 mV/div. It achieves 20,000 to 1 common-mode rejection at DC and low frequencies. It was designed by John Horn.
Type W has two signal inputs, "A" and "B", and a built in precision variable voltage supply, "VC", which is controlled by a ten-turn pot and can vary from either −1.1 V to +1.1 V or −11 V to +11 V. A mode switch selects between displaying A−VC, A−B, or VC−B. The "A−B" mode is particularly useful for displaying the current in a sense resistor, while the other modes provide "slideback" measurements of small variations superimposed on a large constant. An output of VC is provided on the front panel for precision measurements.
Unlike the Type Z, Type W has two gain axes: a decade attenuator and a 1−2−5−10−20−50 selector, reminiscent of Type D from ten years before.
Type W is the only letter-series plug-in with an "infinite resistance" input mode selectable at the front panel. (Types 1A5 and 1A7 have an internal jumper that can be cut.)
Early production Type W in a 556 mainframe won't meet spec for overdrive recovery time, because an overdriven W passes enough common-mode to the mainframe vertical amp to saturate it. The fix, beginning at S/N 3270: Add another stage, to attenuate CM. The new "output amp" circuit board clips onto the rear bulkhead; significant hand mods are required on the chassis. This was also offered as mod kit 040-0447-00.
Type W was created with a pair of type 8056 Nuvistors in the front end. In 1971, at serial number 7000, the Nuvistors were replaced by JFETs to reduce drift. Modification kit 040-0590-00 was offered to retrofit existing instruments.
In the letter-series timeline of differential comparators, Type W, introduced in 1965, follows Type Z and precedes Type 1A5.
Specifications
please add
Pictures
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Front view.
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Top-left view.
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Bottom view.
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Block Diagram
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Differential Comparator, initial version
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Input Attenuators
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Switching Diagram
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A-phase (prototype) Type W
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A-phase (prototype) Type W
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A-phase (prototype) Type W
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A-phase (prototype) Type W
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A-phase (prototype) Type W
