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2
SECTION
INITIAL PREPARATION
2.1
UNPACKING INSPECTION
After carefully unpacking the instrument, inspect the ex
ternal parts for damage to knobs, dials, indicators, surface
areas, etc. If there is damage, file a claim with the carrier
who transported the instrument. Retain the shipping con
tainer and packing material for use in case reshipment is
required.
2.2
PREPARATION FOR USE
Before connecting the instrument to line power, check that
the rear panel 115/230V switch is set to the value nearest
the line voltage and that the fuse is correct for the switch
setting. Check that the plug on the power cord is the mate
for the line receptacle.
2.3
ELECTRICAL ACCEPTANCE CHECK
This checkout procedure provides a general verification of
generator operation. Should a malfunction be found, refer
to the Warranty in the front of this manual.
An oscilloscope, BOH coax cable, and a 50f2 feedthru are
needed for this procedure (figure 2-1). Preset the generator
front panel controls as follows:
Control
Position
FREQMULT
PWR OFF
Frequency Dial
l.Q
Function
AMPLITUDE
Full clockwise
DC OFFSET
OFF
SWEEPWIDTH
OFF
SWEEP RATE
9 o'clock
Perform the steps in table 2-1; monitor the 50n OUT HI
connector at the oscilloscope.
2.4
CHANGING THE OUTPUT IMPEDANCE
The output impedance is normally:
HI
50n@10Vp-p
LO
50J2 @ 1V p-p
Attenuation is normally 0 - 30 dS. Lowest possible ampli
tude is —50 dB.
If simultaneous BOOH and 50n output impedances are
desired:
MODEL 180
50L2„
LOAD
OUT®
Clh
OSCILLOSCOPE
Figure 2-1. Acceptance Check Setup
1.
Change value of R145 from 49912 to 604S2.
2.
Remove R147.
The result is:
HI
5012 @ 10V p-p
LO
60012 @ 10V p-p (low power)
Attenuation is 0 - 30 dB. Lowest possible amplitude is
—30 dB. Square wave rise and fall is < 150 ns.
If 5012 and any other impedance greater than 60012 are
desired, replace R145 with resistor of that value.
If 50 dB of attenuation control is desired in a modified
instrument, change R121 from 33.212 to 1.812. Waveform
quality above 20 kHz will be considerably impaired at
-50 dB compared to a standard instrument.
2-1
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