setting of R127 controls the fixed bias on the grid
R120 is adjusted to give 1-volt root mean square
of V 16. Variation in the regulated 195 volts are.
(rms) out for 40-kHz deviation on the 0-5-kHz
coupled through C100 to the grid of V16. The
deviation range. Capacitor C99 couples the audio
screen voltage for V16 is controlled by the setting
output to the AUDIO OUTPUT binding post.
of R123. Resistors R129, R123, and R192 form a
Plate decoupling for V13B is through R114 and
voltage divider to provide the proper screen
voltage. Plate load for V 16 is R124. The cathode
5-10. Power Supply
of V 16 is held constant by voltage regulator V17,
If the voltage varies, the change is felt on the grid
a. The 115- or 230-volt ac line voltage is
of V16. Tube V 16 changes its conduction, which
stepped up by the high voltage secondary win-
varies the bias on the series regulator V15. Tube
ding of T10. A full-wave bridge rectifier con-
V15 then changes the conduction to obtain the
sisting of CR8, CR9, CR10, and CR11 provides
correct output voltage.
C102, and C103, and inductors L11 and L12
windings. The output at terminals 7 and 8 is 6.3
comprise the filter network for the power supply.
volts ac. The power ON indicator lamp is DS1.
b. Filtered dc voltage is applied to the plates of
The output at terminals 11 and 12 is fed to ballast
series regulator V 15. The regulated 195-volt
tube V14. Resistor R131 in series with V14
output is taken from the cathode of V15. Bias for
provides a regulated 6-volt output, which is used
the grids of V15 is obtained from the plate of dc
for filaments of V1 and V13.
amplifier V16. Part of the load for the cathode of
V15 is comprised of R126, R127, and R128. The