W: Difference between revisions

51 bytes added ,  18 June 2021
JFET conversion a la 1A7
(rearrange mods in SN order)
(JFET conversion a la 1A7)
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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
saturate it.  The fix, beginning at S/N 3270: Add another stage, to attenuate CM.
saturate it.  At S/N 3270, this was fixed, by adding another stage to attenuate CM.
The new "output amp" circuit board clips onto the rear bulkhead;
The new "output amp" circuit board clips onto the rear bulkhead;
significant hand mods are required on the chassis.
significant hand mods are required on the chassis.
This was also offered as mod kit 040-0447-00.
This was also offered as Modification kit 040-0447-00 to retrofit existing instruments.
   
   
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.
Type W was created with a pair of type [[8056]] [[Nuvistor|Nuvistors]] in the front end.  In 1971 (S/N 7000), following the lead of Type [[1A7]], the Nuvistors were replaced by JFETs to reduce drift.  Mod kit 040-0590-00 was offered for 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]],  
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