signals over the full bandwidth, set the low corner-
frequency knob to its full counterclockwise posi-
tion and set the high corner-frequency knob to its
full clockwise position. The corner frequency
increases by a factor of three with each full clock-
wise turn. The photoreceivers have ten settings for
each frequency corner, creating a wide variety of
frequency responses. If the low-frequency corner is
set higher than or equal to the high-frequency cor-
ner, there will be significant attenuation at all fre-
quencies.
In addition, the low-frequency knob has a DC÷30
setting. This is a convenient setting for observing a
small AC signal on a widely varying DC compo-
nent. It will prevent your signal from going off-
scale due to DC amplitude fluctuations.
Note:
With the most sensitive gain setting (10
4
)
the maximum bandwidth is reduced to 20 kHz.
Gain Knob
The overall gain is the product of the gain knob
setting and the wavelength response factor (V/mW)
indicated on the front of the unit. You can increase
the gain by a factor of three by setting the Gain
Multiplier Switch to “
×
3.”
17
