I know that you use the computer.
And, I know you cannot beleave it. Because we cannot understand all of
inside of the computer, we cannot believe it. Now almost all of the equipment of
our life are made with computer, we cannot believe all of them,
camera,mobile,excavator,radio,,,,pets,friends. We could believe the
valve-radio,
because we can draw all of its circuits, in our younger age. So, some friends of
my amateur radio station make and use the valve transmitter and receiver,in
these days.
I will show you that ,the old triode can be used by low
voltage about 12 volts. Please see the circuits. Regenerative radio in old days
can make its activity by 17V-DC. Gain of detector(A to B) is 40dB. Gain of audio
amplifier(B to C) is -16dB.Please see the old time regenerative detector(fig2).
In this circuit, regenerative circuit C2 and L2 made the resonance circuit.
Therefore we must tune it,when we make change the receiving frequency. Please
see fig1. In this circuit, regenerative circuit is made of
high-frequency-transformer. Therefore, I have no need to tune it. In this
radio,from 6MHz to 12MHz,regenerative ratio is constant. In this radio, case
is made of glass-epoxy-board. I can hear BBC with 7MHz dipole antenna.
