Short Illustrated History of the 01A (01A)

ID: 88033
This article refers to the component: To the tube/semiconductor

Short Illustrated History of the 01A (01A) 
17.Jan.06 11:58
5397

Konrad Birkner † 12.08.2014 (D)
Articles: 2333
Count of Thanks: 13
Konrad Birkner † 12.08.2014

RCA

UV200 (Argon-gas filled at 0,05 mm Hg), and UV201 (vakuum) had brass base and tip; 1 amp @ 5 volt filament.

  Marketed by RCA. announced in November 1920 and advertised for sale in December 1920.
----------------------------------------------------------------------------------
UV201A (vakuum) from October 1922, brass base, tipped. 
Filament took .25 anp @ 5 volt.
From mid 1924 on bakelite base, no more tip.
     both types UV201A

----------------------------------------------------------------------------------

The new UX based tubes were throughout untipped and used a Bakelite base.

UX201A
(vakuum) from August 1925; .25 amp @ 5volt, and
UX200A (caesium vapor) from April 1926; .25 amp @ 5 volt.

 UX200A       UX201A

-------------------------------------------------------------------------------------
Cunningham
distributed the same tubes types but under different denomination: C in place of UV  and CX instead of UX. Furthermore the 20x numbers became 30x. 
Consequently C300 = UV200  und  CX301 = UX201.

  Cunningham CX301
-------------------------------------------------------------------------------------
Nomenclature
Soon an abbreviated name came into everydays use for the practically identical tubes having different names. They were simply called the 01  or '01. That can be found even printed on schematics etc. It was kind of a generic name.
Officially this name 01A appeared around 1932 for the shoulder or dome type glass envelopes.

  '01A with "shoulder" (dome type)

RCA had initially no tube manufacturing. They marketed tubes made by Westinghouse or General Electric as a distributor, but under their own brand "Radiotron". Cunningham was also involved in that nearly monopolistic business.
In 1930 RCA eventually established the "RCA Radiotron, Inc." as their own manufacturing subsidiary.
 
Replacement

since the 01A is a perfect functional replacement for a.m. tubes, it is not really an error if it is called for a radio before 1932. But anyway we should always try to state the coincident tube types for the models.

Ref.: Saga of the Vacuum Tube
Photos: Authors collection

To thank the Author because you find the post helpful or well done.