
Model 8640B
TM 9-4935-601-14-7&P
ADJUSTMENTS
5-37. RF FILTER ADJUSTMENT (Cont'd)
Figure 5-6. 256-512 MHz High Band Capacitor Adjustment Orientation
5-38. PRELIMINARY FM ADJUSTMENTS
REFERENCE:
Service Sheets 6 and 7.
DESCRIPTION:
A digital voltmeter is used to correctly set the mechanical position of the FM compensation pot on the RF oscillator (this
is necessary only if either the oscillator or the pot has been changed). Then the DVM is used to adjust the FM calibration
voltage and the offset (balance) voltages in the FM amplifiers.
EQUIPMENT:
Digital Voltmeter ..............................................................................
HP 3480B/3484A
PROCEDURE:
1. Set Signal Generator's controls as follows:
Meter Function
...........................................................
FM
COUNTER MODE:
EXPAND ............................................
Off
LOCK ................................................
Off
Source................................................
INT
AM
...........................................................
OFF
FM
...........................................................
OFF
PEAK DEVIATION
.........................................................2.56 MHz
† See backdating, Tables 7-1 and 7-2.
5-27
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com