ETS-Lindgren 3301C, User Manual

Page: 38 / 62

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Operation
DIP Switches
F
OR
I
NTERNAL
A
TTENUATION
/ L
OW
F
REQUENCY
R
OLL
O
FF
The Model 3301C is calibrated and shipped with all internal attenuation
DIP switches set to OFF. To change DIP switch settings, see the steps on
page 41.
A bank of four DIP switches
located at the SW2
designation on the system
board slide to control the
internal attenuation and the
low frequency roll off.
10 dB Atten— Adds 10 dB of internal attenuation (+/- 10%)
30 dB Atten— Adds 30 dB of internal attenuation (+/- 10%)
1.9 kHz LF Roll Off— Sets the low frequency roll off of 3 dB down at
1.9 kHz
22.0 kHz LF Roll Off— Sets the low frequency roll off of 3 dB down at
22 kHz
Proper Selection of Internal Attenuation
When dealing with continuous wave (CW) signals, no attenuation is needed to
measure field strengths below 0.8 V/m. At approximately this level, the saturation
indicator light will illuminate, indicating a need to switch on the 10 dB attenuator.
When the 10 dB attenuator or 30 dB attenuator is switched on, the Model 3301C
can measure field strengths up to 2.5 V/m or 25 V/m respectively without
saturating. The unit retains 111 dB of dynamic range, but the maximum reading
before saturation is raised by 10 dB or 30 dB while the minimum discernible
signal is also raised by 10 dB or 30 dB. At 2.5 V/m, with the 10 dB attenuator
active, the saturation indicator light will again illuminate. This indicates a need to
switch the 30 dB attenuator on in place of the 10 dB attenuator.