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
GT (Magic eye)
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
DY87 Vacuum tube
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
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
Galena crystal detector
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.
DM70 magic eye
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
EAA91 vacuum tube
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
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.