HP TM 11-6625-2779-14&P - Manual (Page 36)

Section V Model 3555B
Figure 5-1. Balanced BNC to 310 Plug
function, remove or clip the shorting bar
from across A1 R17 (see Figure 7-2).
b. Remove the 150 BAL decal from the small
envelope supplied with the set and stick it
over the existing 135 BAL decal.
c. Adjust the 150 function as described in
Paragraph 5-20 in this manual.
5-7. PERFORMANCE CHECKS.
5-8. The performance checks presented in this
section are in-cabinet checks designed to compare the
Model 3555B with its published specifications. These
checks can be used for incoming inspection, periodic
maintenance checks and to verify performance after
adjustment or repair. A performance check test card
appears at the end of this section which can be used to
record the specification performance of your set.
5-9.
LEVEL ACCURACY CHECKS.
a.
Connect only the 654A and 3555B as
shown in Figure 5-2 and set the 3555B
controls as follows:
FUNCTION ........... CARRIER, 75 UNBAL
INPUT ................................. TMS, TERM
RANGE...................................... +10dBm
b. Set the 654A frequency to 20kHz,
IMPEDANCE to 75 UNBAL and adjust the
output level for +10dBm. If the calibration
of the 654A is questionable, first connect
the output of the 654A through a 75 ohm
termination, directly to the input of the
3440A/3445A (3555B not connected) and
measure the voltage. This level should be
866mV rms. If it is not, adjust the 654A
amplitude control until it is and note the
654A meter indication for future reference.
Now that the 654A calibration has been
verified, disconnect
Figure 5-2. Level Accuracy Check
5-2