HP 339A - Output Buffer and Attenuator Functionality

Model 339A
Section VIII
8-46. Output
Buffer
and
Attenuator. The oscillator
signal is
applied
to the output buffer amplifier
(A1U3)
through
theoutput
LEVEL VERNIERcontrol. The level
vernier varies
the
output level of the buffer amplifier from
approximately
6.5
V
rms
to
1.8
V rms. The
output
of the
buffer
amplifier
is divided by the output attenuator in 10
dB V steps
from 3
V rms full-scale to 3 mV rms full-scale
into a 600
ohm load. The
attenuator also includes an
OFF
position
which disables the oscillator output and
terminates the OUTPUT
terminals with
a 600 ohm
resistive load. The
combination of the output
attenuator
and
level vernier
permit
the selection of output levels
from 1
mV
rms to
greater-than 3
V
rms into
600
ohms.
The
oscillator
output
level may be monitored on the
meter when the OSCillator
LEVEL function
is selected.
A zener diode protection
circuit protects the oscillator
circuitry from the accidental
application of voltage
to the
oscillator OUTPUT terminals.
8-9