DIY soldering kit Tube valve display base with Barretter Tube 3 volt easy build
This is a kit, you need to solder the components. Everything provided except solder, instructions supplied.
This includes the Russian tube in picture.
Other B4 type valves can be displayed if there is a centre hole in the valve .
About the Barretter and some uses;
Used to limit current in early radios and for detection in the very early days- see below.
The hot-wire barretter depends upon the increase of a metal resistivity with increasing temperature. The device is biased by a direct current adjusted to heat the wire to its most sensitive temperature. When there is an oscillating current from the antenna through the extremely fine platinum wire loop, the wire is further heated as the current increases and cools as the current decreases again. As the wire heats and cools, it varies its resistance in response to the signals passing through it. Because of the low thermal mass of the wire, it is capable of responding quickly enough to vary its resistance in response to audio signals. However, it cannot vary its resistance fast enough to respond to the much higher radio frequencies. The radio frequencies are essentially removed, and the sound is demodulated because the current through the circuit varies with the changing wire resistance. Headphones are connected in series with the DC circuit, and the variations in the current are rendered as sound.