D: Difference between revisions

9 bytes added ,  23 November 2010
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Type D was [[introduced in 1954|introduced]] with the [[531]] and [[535]] in 1954 as Type 53D,
Type D was [[introduced in 1954|introduced]] with the [[531]] and [[535]] in 1954 as Type 53D,
was briefly renamed Type 53D/54D in 1955 with the introduction
was briefly renamed Type 53D/54D in 1955 with the introduction
of the [[541]] and [[545], then quickly renamed Type 53/54D,
of the [[541]] and [[545]], then quickly renamed Type 53/54D,
then shortened to Type D in 1959 with the introduction of
then shortened to Type D in 1959 with the introduction of
the 5xxA scopes.  Its last year was 1968.
the 5xxA scopes.  Its last year was 1968.


Some production used a pair of 5814 tubes at the input while others used 12AU7's.
Some production used a pair of [[5814]] tubes at the input while others used [[12AU7]]'s.
These two tube types have different heater currents, and because the heaters are
These two tube types have different heater currents, and because the heaters are
series-wired, you cannot switch from one type to the other without circuit modification.
series-wired, you cannot switch from one type to the other without circuit modification.