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A [[545]] with a Type A has a system risetime of 18 nanoseconds and a bandwidth of 20 MHz.   
A [[545]] with a Type A has a system risetime of 18 nanoseconds and a bandwidth of 20 MHz.   


The plug-in uses a [[12AU6]] in the front end as a cathode follower. 
Although 1959 was the first year one could find a "Type A" in the catalog, the same instrument
This input stage drives the second stage, a differential amplifier made of two more 12AU6 tubes. 
with earlier "Type 53/54A" nomenclature was in the August 1956 Short Form catalog, and its  
The second stage drives the output stage, a pair of cathode followers made of both halves of
Type 53A ancestor was in the August 1954 catalog which introduced the first 500-series scopes,  
a [[12AT7]] tube.  The plate of each output tube is connected to the cathode of the other output
the [[531]] and the [[535]].
tube by a 5 nF capacitor.  This "cross-bootstrapping" extends the high-frequency response.
 
Although 1959 was the first year one could find a "Type A" in the catalog, the same
instrument with earlier "Type 53/54A" nomenclature was in the August 1956
Short Form catalog, and its slower Type 53A ancestor was in the August 1954
catalog which introduced the first 500-series scopes, the [[531]] and the [[535]].
Type 53A has only three tubes, and a bandwidth of 10 MHz in the 530 mainframes.
Tek never documented its performance in the 540 mainframes.


Type A was the first letter-series plug-in to be discontinued, in 1962.
Type A was the first letter-series plug-in to be discontinued, in 1962.
Line 38: Line 30:
==Specifications==
==Specifications==
[[Category:Specifications needed]]''Please add''
[[Category:Specifications needed]]''Please add''
Bandwidth is 10 MHz in the 530 mainframes.
Catalogs don't list 53A performance in the 540 mainframes.  The Factory Cal Procedure says 20 MHz, but this is wrong.  (A Type 53A's measured 3 dB point was around 17 MHz while a Type A made 23 MHz. Furthermore, the front-panel artwork reads ".017 usec" for 53A and .015 for A.)
==Internals==
Type 53A has only three tubes, and no [[T-coil peaking|T-coils]].
The plug-in uses a [[12AU6]] in the front end as a cathode follower. 
This input stage drives the second stage, a differential amplifier made of two more 12AU6 tubes.
The second stage drives the output stage, a pair of cathode followers made of both halves of
a [[12AT7]] tube.  The plate of each output tube is connected to the cathode of the other output
tube by a 5 nF capacitor.  This "cross-bootstrapping" extends the high-frequency response.


==Pictures==
==Pictures==

Revision as of 23:26, 8 October 2021

Tektronix Type A
20 MHz amplifier plug-in
Tektronix Type 53A

Compatible with 500-series scopes

Produced from 1954 to 1962

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix Type A is a single-channel preamp introduced in 1959 for 500-series scopes. It provides two inputs and has a switch to select between them. A 545 with a Type A has a system risetime of 18 nanoseconds and a bandwidth of 20 MHz.

Although 1959 was the first year one could find a "Type A" in the catalog, the same instrument with earlier "Type 53/54A" nomenclature was in the August 1956 Short Form catalog, and its Type 53A ancestor was in the August 1954 catalog which introduced the first 500-series scopes, the 531 and the 535.

Type A was the first letter-series plug-in to be discontinued, in 1962. Customers were told to get Type B instead, although it cost more.

Specifications

Please add

Bandwidth is 10 MHz in the 530 mainframes.

Catalogs don't list 53A performance in the 540 mainframes. The Factory Cal Procedure says 20 MHz, but this is wrong. (A Type 53A's measured 3 dB point was around 17 MHz while a Type A made 23 MHz. Furthermore, the front-panel artwork reads ".017 usec" for 53A and .015 for A.)

Internals

Type 53A has only three tubes, and no T-coils.

The plug-in uses a 12AU6 in the front end as a cathode follower. This input stage drives the second stage, a differential amplifier made of two more 12AU6 tubes.

The second stage drives the output stage, a pair of cathode followers made of both halves of a 12AT7 tube. The plate of each output tube is connected to the cathode of the other output tube by a 5 nF capacitor. This "cross-bootstrapping" extends the high-frequency response.

Pictures