Data sheet available HERE

Data sheet available HERE

A curious component from the 1930-1940. It's a "wall picture antenna" found with a great surprise inside a Telefunken receiver during its restoration.. Pratically it's a series of coils behind the hand made painting with the function of antenna for medium and short waves.

The tube you can see here is a CV3929, a mini penthode used as IF amplifier in the 10.7Mhz stages. It's one of the smallest vacuum tubes ever made for non military uses. Was used inside little portable radioreceivers build across the 50'.

The box you can see on the left picture can be called "the granfather" of the actual integrated circuits.. After the war infact in some receivers were used this integrated R/C network. They usually contens two, three resistors and one capacitor. The typical stage were was used is the MF stage. In the years, often, the resistors inside this "box" were defective, and cause of many strange faults...

Component used as tuning indicator inside some top class receivers. The top of the tube is a circle with green phospores. Its wideness is funcion of the strenght of the received carrier. Inside this tube there is a little triode used as preamplifier of the AGC (Automatic Gain Control).

This tube was used only in early TV sets. It's simply a diode but with 10-15.000Volts of nominal working voltage. Its heather voltage usually was generated by a only one coil around the flyback transformer. The voltage rectified from this tube (EHT) is necessary to the right cathodic ray tube polarization.

VT179tube

Vacuum tube model VT179 used by the U.S. Army during the 2nd world war inside transceiver equipment. After, in the years, it will be left without use

This is a particular of a galena crystal  used as radio rivelator in the first receivers called "galena radios". Those receivers works without supply; The RF signal itself driven the piezo headphones.

This kind of vacuum tube called "magic eye" was used in 40' and 50' as power indicator, recording levels,  tuning setting, when the VU meter does not  was still discovered

This is a vacuum tube model EC157, a triode used inside military radars during the 2nd world war. Its center work frequency is over 4000Mhz and for this reason it was placed inside microwaves devices as amplifier. Note that the anode and the grid of this tube are the two rings on the top of the bulb, not in the socket as all other vacuum tubes..

Double diode used as RF rivelator inside radio receivers. Note the little dimensions of this component due to optimize its gain at high frequency

The 300B is still now one of the most popular vacuum tubes for HI-FI power amplifiers.. It is a pure triode with direct heating. With an anodic voltage of 1000V (Yes 1000V!!!) you can obtain a great output power, and linearity just for the best power audio amplifiers never heard.

Vacuum tube model 2A3 used inside military equipment as RF power amplifier.  (short and long waves). Now many people use it as HI-FI audio power amplifier, usually in A-class. With its power (about 20W) this tube can drive without problems any kind of loudspeaker, with a good fidelity.

A little part of the US ARMY vacuum tubes I keep stored.