The ECH11 is a triode hexode frequency changer for use in a superhet receiver.
The typical valve line-up would be: frequency changer ECH11, IF amplifier EF11 x 2, demodulator, AGC detector and first audio stage EBC11, push-pull audio output EDD11 and rectifier EZ11.
The Footless base with the spigot covering the evacuation tube. Internally a hard glass base holds the supports that the electrodes are held by. No pinch is involves and lead inductances are reduced allowing higher working frequencies.
Telefunken Footless valves had a steel envelope similar to the RCA metal valves whereas Tungsram use a glass envelope.
Made in Hungary.
The wide glass tube envelope is 39 mm in diameter, and excluding the footless base pins is 48 mm tall.
Reference: Data-sheet. Type ECH11 was first introduced in 1939. See also1939 adverts.
