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Country:  Czechoslovakia
Manufacturer / Brand:  KNN, Praha
Year: 1927 ?? Category: Broadcast Receiver - or past WW2 Tuner
Valves / Tubes 1:
Main principle TRF with regeneration
Wave bands Broadcast (MW) and Long Wave.
Power type and voltage Storage and/or dry batteries
Loudspeaker - only for Earphone!
Power out
from Model: Negadyn - KNN, Praha
Material Wooden case
Shape Portable set > 8 inch (usable also without mains)
Notes Negadyne is a certain high sensitive demodulating circuit using a space charge tetrode, where positive feedback acts through interaction between the grids, hence no reaction coil is necessary. Alternatively a second mode can be selected: Crystal detection with audio amplification.

Model page created by Gabriel Toth. See "Data change" for further contributors.

All listed radios etc. from KNN, Praha
Here you find 42 models, 6 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.