Section V
TM 11-6625-2781-14&P-2
ADJUSTMENT PROCEDURES (cont' )
d
5-28. APC Sampler Adjustment
REFERENCE: Service Sheet 6.
DESCRIPTION: A 10 kHz square-wave input is substituted for the 200-310 MHz local oscillator signal. The APC sample
is adjusted for sampling efficiency and dc-balance. Sampling efficiency is adjusted by observing a sampling waveform
on top of the 10 kHz waveform, and adjusting the second and third samples for equal amplitude.
Figure 5-11. APC Sampler Adjustment Test Setup.
EQUIPMENT:
Oscilloscope ................................ ................................ ................................ ......................... HP 180A/1801A/1821A
Square Wave Generator ................................ ................................ ................................ ............................. HP 211B
Extender Cable Assembly ................................ ................................ ................................ ............... HP 11592-60015
Interconnecting Cable Assembly ................................ ................................ ................................ ..... HP 11592-60016
BNC Cable Assembly (2) ................................ ................................ ................................ ........................ HP 10503A
RF Test Cable................................ ................................ ................................ ................................ . HP 11592-60001
Cable Assembly (with test clips added) ................................ ................................ ................................ ... HP 10501A
Test Fixture: BNC Tee ................................ ................................ ................................ ............................ UG-274B/U
Blocking Capacitor, 500 uF, 3W Vdc ................................ ................................ ................................ ... HP 0180-1734
BNC Female Connector (2)................................ ................................ ................................ ................. HP 1250-0083
1. Connect the test setup in Figure 5-11. Set the controls as follows:
ANALYZER:
RANGE MHz ................................ ................................ ................................ ................................ ................... 0-110
TUNING STABILIZER................................ ................................ ................................ ................................ ...........On
BANDWIDTH ................................ ................................ ................................ ................................ ................... 3 kHz
SCAN WIDTH ................................ ................................ ................................ ................................ ....PER DIVISION
5-18
