B Supply
The “B” supply of the ARBE-III is designed to provide 5 different regulated DC voltages
(22, 45, 67, 90 and 135 volts). The
total
“B” current available is 60 ma. This means that
any combination of voltages used together should not exceed 60 ma. Each voltage can
provide up to 30 ma at less than 5 mv ripple. The high voltage is derived from a separate
winding on the power transformer. The high voltage is rectified, filtered, and regulated
with a three terminal regulator which is set for 135 volts. The remaining “B” voltages are
derived by the use of a zener diode voltage network. The “B” voltages are approximately
within 5% of the stated voltage. The high voltage regulator is protected against overload
conditions (short circuits). If
any
of the “B” supply outputs are accidentally shorted out,
no damage will occur to the ARBE-III. A short circuit condition will cause excessive
heat build up because it’s an abnormal condition.
C supply
The “C” supply of the ARBE-III is designed to provide 3 different regulated voltages
(-4.5, -9, and -22 volts). Each voltage can provide up to 20 ma at less than 1 mv ripple.
The voltages are derived from a 3rd winding on the power transformer. The voltage is
rectified, filtered, and derived by the use of a zener diode voltage network. The “C”
voltages are approximately within 5% of the stated voltage.
Use of the ARBE-III
You should become familiar with the circuitry of your radio
before
attempting to connect
it to the ARBE-III. Incorrect connections and or wrong “A” supply voltage settings can
instantly destroy a set of tubes. A schematic diagram is a useful tool when attempting to
hook up your radio for the first time.
Antique Radios Inc
is a potential source for many
old radio schematics. Additionally, numerous wiring diagrams are available on our
website.
www.arbeiii.com
These will show how to make the electrical connections for
many of the early battery operated radios from the 1920’s. As a minimum, you need to
know the following information:
1.)
Filament voltage and current requirements of the tubes in your radio.
2.)
B supply voltage requirements.
3.)
C supply voltage requirements if applicable.
4.)
Common reference point of the supply voltages.
The most critical supply voltage is the “A” supply. An incorrect voltage can destroy a
complete set of tubes instantly. A tube manual will show the correct voltage levels for
many commonly used vacuum tubes. A partial listing of tube voltages and current
requirements are included on the following page.
3
Summary of Contents for ARBE-III
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