Ornitz, Barry L wrote:
>
> VT4B = 211 Triode (very popular with the modern tube audiophiles*)
> VT30 = 01-A Triode (a rather early triode)
> VT-31 = 31
> VT-80 = 80 (rectifier, ancestor of the 5Y3 rectifier)
Wrong, Barry. The type 30 was a second generation tube brought out by
RCA about 1932 almost a decade later than the 01A. It was aimed at
the portable and battery operated radio market where filament voltage
and current drain was much lower than the 01A. The 01A, for example
had a 5 volt filament @ 0.25 A. The 30 was only 2 volts @ 0.060A for
the same transconductance as the 01A.
The 31 was a companion tube meant to be an audio power output. Its
filament voltage also 2 volts but current drain 0.130A. Both were
triodes. Note that the filament voltage was more practical, being the
voltage of a single lead acid cell.
VT, btw I believe was first introduced during WWII for standard
military designations and stood for Vacuum Tube.
The 80, as you indicate, was an antecedent of the 5Y3 and had
identical characteristics. Its base, unlike the octal 5Y3, used a 4
pin base just like the 01A.
This information comes from the 1934 RCA tube manual for which I paid
all of 25 cents, half my allowance for a month!
Forrest Gehrke k2bt
Received on Tue Oct 07 1997 - 09:32:57 EDT
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