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The "4 variants" radio designer was supposedly produced since 1967 by the Riga enterprise.
The radio designer is similar to the "From simple to complex" set of the same enterprise, the page of which is available on the site.
Four designs can be assembled from the "4 options" radio constructor: detector receiver;
detector receiver with RF amplifier;
straight receiver with a single-ended output and the receiver of direct amplification from a push-pull output.
The last two schemes can be collected in a beautiful case with the name "Jura" (Jura).
The first cosmonaut Yuri Gagarin.