Old radios, englishAlte Radios, deutschRadios antiguas, españolMusée de radio, francaisRadio antiche, italiano
Please click your language flag. Bitte Sprachflagge klicken.
Info - Help 

EF50

Country:  Europe      Brand:  Common type Europe 
  Developer:  Philips; - Eindhoven; Netherlands 
  Tube type:  Vacuum Pentode   RF/IF-Stage   Controlling (mu) 
Tube ID = 2497
previous  |  next
Identical to EF50 = VT-250 = Z90 = VR91 = 10E/92 = ARP35 = ZA3058 = CV1091 = CV1578 = 63-SPT
First Series   1939 Tube leaflet collection E.Erb Philips-Book [178] Archive = 1939
First Source (s) Oct.1939 : -- Original-techn. papers.
Predecessor Tubes 4673  
Successor Tubes 1948 EF42   EF80  

Base Loctal-9-Pin (B9G) (Codex=Y)
Filament Vf 6.3 Volts / If: 0.3 Ampere / -: Indirect / -: Parallel / series AC/DC /
Tube prices 0 Tube prices (visible for members only)
Literature Taschenbuch zum Röhren-Codex 1948/49   

  ef50.gif
  Courtesy Bureau Belper (De Muiderkring, Bussum), Scan Frank Philipse
Karel De Reus
ef50.jpg
Courtesy Thomas Rapp, roehren-museum.de
Olaf Toenne

 
Variants
lo31.png
RTT 1974 (Franzis) 13. Auflage
Martin Renz

 
ef50_techdat01.png
SEL Handbuch 1964
Peter Hoddow

Usage in Models (calculation each 25th of the month)   1= 1940?? ; 1= 1941 ; 1= 1942 ; 2= 1943? ; 3= 1946 ; 1= 1947 ; 1= 1948?? ; 1= 1948? ; 6= 1948 ; 1= 1950?? ; 1= 1951?? ; 1= 1952 ; 1= 1954 ; 1= 1955 ;
Number of Models at Radiomuseum.org with this tube (valve, valves, valvola, valvole, válvula, lampe):   22

  Variants


Wireless World
Jacob Roschy
EF50*original-version

as all glass valve yet without aluminium can, but with hooked pins, in order to plug-in and twist the valve by the bayonet-lock principle, which has been abandoned in the later EF50s mass production.

17.Mar.2006 Jacob Roschy

Further Information for

EF50    

EF50 (EF50)  (16.03.2006) Jacob Roschy Clicks: 498     Replies: 0
  The VALVE development continues rapidly and concerns both the characteristics and method of construction.   A new Mullard type of valve of exceedingly unorthodox construction is described in this article. development of the technique of radio valve manufacture was assisted in the early stages by the experience gained in the product ion of incandescent lamps. Although originally developed for the lamp, the glass bulb and foot, with its pinch, were adopted for the vacuum-tight envelope of the valve. Recent receiver development, however, has raised Problems which are difficult of solution with the existing valve    technique. This is especially so in the case of short-wave and television apparatus. THE Some of the difficulties encountered in the original method of construction is developed from incandescent-lamp manufacture, can be summarised as follows: (1) In certain valves of the old construction it was found necessary to connect anode and control grid to the opposite ends of the valve, which sometimes complicates receiver design.

 

Original EF50?  (12.03.2006) John Turrill Clicks: 876     Replies: 10
Dear members,                            I wonder if anyone has more information on what I believe was the original version of the EF50 vhf pentode, which I'm told had a metallised coating (not the aluminium can of later versions) and L-shaped pins, so that the valve had to be pushed in and twisted to lock? (1939?)     I'm told there were problems with side pressure on the pins cracking the glass, but I wonder how many were produced?     A good photograph or information on the whereabouts of one would be most welcome!    Regards from                      John.
More ...
 
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]
  
rmXorg-09 About Radiomuseum.org | Contact | Press | Privacy | Copyright | Logos | send2friend 22NovX