Shortwave Converter 1936

Short-wave Converter

In Russia 1930 - 1940 years shortwave converters were very popular in radio listeners and radio amateurs. Following the publication of structures converters demand for shortwave-parts have increased substantially, and most amateurs wanted to have the converter - a simple and cheap enclosure for the long-wave receiver, greatly expanding the number of radiostations and allows reception of distant radiostations at any time of day.
Of course, not every listener can build a converter, even with the complete set of parts. Not all have had enough experience to build improvised radio sets. Therefore, Moscow Plant. "Radiofront" has begun production of converters.
I have the model "KA-116" was produced from "Radiofront" in 1936. The mixing tube is pentode, type SO-182. Feedback is not regulated, a feedback coil is in circuit shield grid. In the rectifier is applied to the power transformer sectional winding, which allows the inclusion of the voltage at 110, 120 and 220 V. Sections switching is done by a small rearrangement of the forks of the pair of nests in the other.

As the valve push tube used BO-125, but there is a possibility to use some others tubes, such as BO-202, SI-104, S-118. The filter consists of a rectifier resistance and 2 capacitors.
Antenna capacitor consists of a piece of mounting wire, surrounded with him over the sheets of paper a number of thin insulated wire.
There are two switches in the converter. When the switch 1 open, the admission is made on the converter. When switch 1 is closed, the antenna is connected to the receiver's "antenna" terminal. When the switch 1 connects the antenna to the receiver, it breaks the converter's power chain. Thus it is possible to switch from reception to the long-wave radio-receiver at the reception with the converter without antenna reconnection.
The converter has a repousse metal chassis. At the chassis top are the condenser and rotating machinery, power transformers, coils, high frequency choke and switch sections of primary winding of power transformer. Other details positioned under the chassis horizontal panel.
The rear wall of the converter box cardboard, there are the necessary instructions regarding the inclusion of the converter.
Converter overlaps the range of from about 17 to 35 or 40 meters. The application for setting up only one handle extremely simplifies the setup process and makes the reception of shortwave stations accessible to the most inexperienced listeners. Slowing given rotating mechanism, is a sufficient, but the smooth progress of the mechanism is not very good.

Here, I give this picture of those years where the converter is composed of radio.

Converter's schematic diagram

KA-116 short-wave converter principal electric scheme

Converter's connection with SI-235 popular russian radio-reciever