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ANTENTOP- 03- 2003, # 004 Vacuum Tubes


E K L - 34

The 5-tube R-set of direct amplification "EKL-34" was produced by Leningrad Kozitsky Works (earlier spelled "Kazitsky") from 1934 and was an improved version of the "EKL-4" set. The difference was a better technology and characteristics. In the author's collection the set has the serial number 3903.


Set of tubes: SO-124, SO-118, SO-118, UO-104, VO-166

Tuning range:

MW 225-720 m; LW 680-2000 m

Sensitivity - 40-300 mcV/m

Power output 0.8 W

Power consumption 65 W

Dimensions 520x420x260 mm

EKL -34


The AC-switch of lever-type is placed on the left side of the base. The vertical moving dial of 20x25 mm has a pointing in fixed units, a light, a wire pointer. Beside the dial there is the control handle of the 3-section tuning capacitor . The two knobs on the base control volume and positive feedback. Wire potentiometers wound on wooden rings are used for control. In the center a small lever with horizontal move is the band selector. The two levers to the left serve for fine tuning of RF coils for maximum sensitivity during listening. The set has a couple of adapter terminals to connect with a gramophone. The switching of the AC voltage of 110-127-220 V is made by resetting of the jumpers

EKL- 34, inside view

on the net transformer. The loudspeaker has a 3-section field coil. The outer side of the glued paper cone is made of natural leather.


The R-set is built according to the structure of direct amplification 1-V-2 with controlled positive feedback using tubes of the indirect 4-volts heating. The RF amplifier on a tetrode SO-124 has the cap coupling


with the aereal. A SO-118 tube works as the detector. The first AF step is built on a similar tube. The output audio step is working on a direct heating triode UO-104. The scheme is sourced on a rectifier VO-116. All the resistors are carbonic ("Kaminsky" type). The filter caps are paper-made (Leningrad "Krasnaya Zarya" Works), the rest are of open construction made of mica.

EKL 34, the schematic



We should note, that even the latter system of marking was not quite consistent. For instance, one and the same letter "F" was used to denominate a high-gain triode and an output AF penthode (6F5 and 6F6). Initially the figure taking the third place in the

marking showed the number of outer terminals (including the filament and the outlet of the metallic case). That hindered denomination of new valves similar to the earlier produced ones with the same number of

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February 29, 2020 23:07

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