Please click your language flag. Bitte Sprachflagge klicken.


Information - Help 
ID = 71679
United States of America (USA)
Brand: Eveready (Ever Ready), AENMC / National Carbon Company (NCC); Columbia
Developer: Westinghouse El. & Mfg. Co. - see also Canadian W. 
Tube type:  Screen-grid Tetrode   RF/IF-Stage 
Identical to ER224 = UY224 = 224 = 124 = C324 = 424

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 / Specified voltage AC/DC

According to Tyne, page 321, this first US 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.

Dimensions (WHD)
incl. pins / tip
x 123 x 45 mm / x 4.84 x 1.77 inch
Weight 50 g / 1.76 oz
Information source Taschenbuch zum Röhren-Codex 1948/49   
ER224: scc
Christian Schaufelberger

More ...
ER224: Fin Stewart
Fin Stewart


from Just Qvigstad

You reach this tube or valve page from a search after clicking the "tubes" tab or by clicking a tube on a radio model page. You will find thousands of tubes or valves with interesting links. You even can look up radio models with a certain tube line up. [rmxtube-en]