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224

Information - Help 
ID = 2654
       
Country:
United States of America (USA)
Brand:
Developer: Westinghouse El. & Mfg. Co. - see also Canadian W. 
Tube type:  Screen-grid Tetrode   RF/IF-Stage 
Identical to 224 = 324 = 24 = 24A = UY224 = Y-224 = RENS324 = NY224 = FY224 = SY224 = A224 = PAC224 = D224 = EY-224 = ER224 = T224 = GSY224 = A.C.224
Similar Tubes
Normally replaceable-slightly different:
  224S ; 22AC
First year Apr.1929 Saga of the Vacuumtube, Tyne page 321 and 322
Predecessor Tubes UY227  

Base UY-Base, 5 Pins (USA, April 1927) Top contact with a cap
Was used by Radio/TV-reception etc.
Filament Vf 2.5 Volts / If 1.75 Ampere / Indirect / Parallel, (AC/DC)
Description

According to Tyne, page 321, this first AC screen-grid tetrode, the UY224, later called 224 or 24' in the US was introduced in April 1929. It derived from the first US indirect heated triode UY227 from 1927 with the same heater-cathode combination. The oxide-coated filament operates at 2.5 volts AC or DC, taking 1.7 amperes. With 180 volts on the anode (-1.5 inner control grid, 75 volts on screen grid) is resulting 4 milliamperes, the amplification factor is a bout 420, the anode impedance 400 000 ohms and the mutual conductance 1050 micromhos. Direct capacitance between anode and control grid is less than 0.01 picofarad which made Neutrodynes obsolete beginning in 1929.

 
Text in other languages (may differ)
Literature Rider's Perpetual, Volume 2 = 1932 and before   Sparks-Withington, p.2-60
Taschenbuch zum Röhren-Codex 1948/49   
  247_sch.png
  224: Allied Radio Corp.
Günter Kudicke
 
silvertone224.jpg
224: A. De Poi's collection
Alessandro De Poi

 
448_8.png
224: Telefunken Werkstattbuch
Wolfgang Bauer

 

Usage in Models 1= 1928?? ; 1= 1928? ; 1= 1929?? ; 47= 1929? ; 137= 1929 ; 17= 1930?? ; 22= 1930? ; 151= 1930 ; 14= 1931?? ; 28= 1931? ; 98= 1931 ; 3= 1932?? ; 8= 1932? ; 104= 1932 ; 5= 1933?? ; 8= 1933? ; 4= 1933 ; 6= 1934?? ; 4= 1934? ; 2= 1935?? ; 1= 1935? ; 1= 1936?? ; 1= 1937? ; 1= 1939? ; 2= 9999

Quantity of Models at Radiomuseum.org with this tube (valve, valves, valvola, valvole, válvula, lampe):667


Forum contributions about this tube
224
Threads: 1 | Posts: 3
Hits: 2832     Replies: 2
UY224 odd structure
Joe Sousa
13.Jun.10
  1

Fellow radiophiles,

I came across this strange looking UY224 screen grid AC heated tube in the back of an Atwater Kent 82

Can anyone explain the structure?

Regards,

-Joe

      

 

 

Emilio Ciardiello
14.Jun.10
  2

Dear Joe,

In addition to the standard 24 tetrode, Sibley lists the 24A version, designed for low secondary emission from plate. Maybe that the tube in the pictures above is the 24A. The odd shape can then be explained as a design choice to minimize the effects of the secondary emission. The draft below shows a cylindrical structure A and a square structure B, that approaches the one in your pictures. K are the cathodes and P are the plates. In the boxed structure B electrons extracted from the plate are preferably directed to other segments of the plate itself, so minimizing their action in the grid space.

        

It is only a guess, I know. But it could explain both the boxed plate and the asymmetry of the cathode displacement.
 

Regards, Emilio

Joe Sousa
23.Jun.10
  3

Dear Emilio,

Thanks for the explanation. John Stokes shows a picture of this UY224 as an early version on page 66 of his "70 years of Radio Valves and tubes" book from 1982.

Regards,

-Joe

 
224
End of forum contributions about this tube

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