Spurious Responses

TM 11-6625-2781-14&P-2

Section IV

PERFORMANCE TESTS (cont'd)

4-28. Spurious Responses (cont'd)

DESCRIPTION:

To verify spurious response level the two-tone method of measuring intermodulation distortion will be used. The outputs

of two signal generators, tuned 50 kHz apart, are applied to the spectrum analyzer RF INPUT. The generator levels are

adjusted equally to -43 dBm (-40 dBm total power) at the analyzers input mixer. No IM products from 100 kHz to 110

MHz should be present above -110 dBm (-70 dB from -40 dBm).

Figure 4-12. Intermodulation Distortion Test

EQUIPMENT:

Signal Generator................................ ................................ ................................ ................................ ......... HP 606B

Signal Generator................................ ................................ ................................ ................................ ......... HP 608F

BNC Cable Assembly (2) ................................ ................................ ................................ ........................ HP 10503A

BNC Tee................................ ................................ ................................ ................................ ................. UG-274B/U

1. Connect the test setup shown in Figure 4-12 and make the following control settings:

ANALYZER

RANGE MHz ................................ ................................ ................................ ................................ ................... 0-110

BANDWIDTH ................................ ................................ ................................ ................................ ................... 1 kHz

SCAN WIDTH PER DIVISION ................................ ................................ ................................ ....................... 20 kHz

FREQUENCY ................................ ................................ ................................ ................................ ............... 10 MHz

INPUT ATTENUATION................................ ................................ ................................ ................................ ...... 0 dB

SCAN TIME PER DIVISION ................................ ................................ ................................ ........ 2 MILLISECONDS

LOG REF LEVEL ................................ ................................ ................................ ................................ ......... -40 dBm

TUNING STABILIZER................................ ................................ ................................ ................................ ...........On

VIDEO FILTER ................................ ................................ ................................ ................................ .................. OFF

SCAN MODE ................................ ................................ ................................ ................................ ....................... INT

SCAN TRIGGER ................................ ................................ ................................ ................................ ............ AUTO

SIGNAL GENERATORS

Signal Generator No 1 (606B) FREQUENCY ................................ ................................ ............ 9 950 MHz (approx )

Signal Generator No 2 (608F) FREQUENCY ................................ ................................ ................. 10 MHz (approx )

AMPLITUDE ................................ ................................ ................................ ................................ .. -40 dBm (approx)

4-17