Please click your language flag. Bitte Sprachflagge klicken.


Information - Help 
ID = 45194
United States of America (USA)
Brand: General Electric Co. (GE); Bridgeport CT, Syracuse NY
Developer: General Electric Co. (GE); Bridgeport CT, Syracuse NY 
Tube type:  Secondary Emission Tetrode 
  <1925 no serial production. For instance only development samples. *****
Identical to Pliodynatron
Predecessor Tubes Dynatron  

Base Side contacts.
Filament Direct / Specified voltage AC/DC
Description This tube has four electrodes:
A filamentary cathode, a helical (or flat and perforated) anode at high potential and an outer cylinder (or flat plate) called "3rd electrode" kept at a lower potential.
The secondary electrons bounced back from the 3rd electrode are collected by the anode.
An additional grid (Discharge Controlling Member) between the filament and anode is inserted in order to control the main stream of electrons.
The Pliodynatron behaves as a true negative resistance device.

Dr Albert W.Hull of the GE Research lab. had issued a paper to the I.R.E. in January 1917, where he described his Dynatron as well as the Pliodynotron. The paber was published in the Proc.I.R.E.,1918, 6. 
Text in other languages (may differ)
Information source Patent   US 1 385 873
Saga of the Vacuum Tube, Tyne   p.146

Pliodynatron: US Pat. 1385873
Wolfgang Holtmann

Pliodynatron: US Pat. 1385873
Wolfgang Holtmann

More ...


Forum contributions about this tube
Threads: 1 | Posts: 2
Hits: 2145     Replies: 1
Pliodynatron (exctract)
Georg Richter

The Pliodynatron by Dr. Hull of General Electric is mentioned in the book "Radio Telephony", written by Alfred N. Goldsmith (fellow of the 'Institute of Radio Engineers', member of the 'American Institute of Electrical Engineers', director of the 'Radio Telegraphic and Telephony Laboratory' and professor at 'The College of the City of New York') , issued in 1918 at 'The Wireless Press, Inc., New York).

I have extracted the Pliodynatron related pages 102 and 174 to 181, even if there is a mixture between Pliodynatron and Pliotron (in general, see also CA_Pliotron, G_Pliotron, P_Pliotron and later U_Pliotron) and Dynatron.

The chapters are

  • Pliodynatron Construction (page 102)
  • Hull's Pliodynatron Modulation Control (page 175)
  • Modulation Characteristics of Pliodynatron (page 176)
  • General Electric Company Pliodynatron Radiophone (page 177)
  • Effect of Internal Bulb Coupling (page 179)


Best Regards



Konrad Birkner † 12.08.2014

May I add that according to Tyne, "Saga of the Vacuum Tube" (p.146, fig.8-14 and 8-15) Dr.Albert W.Hull had sent a paper to the I.R.E., where he described both his Dynatron and the Pliodynatron. (Proc. I.R.E., 1918, 6).


End of forum contributions about this tube

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]