TM 11-6625-2781-14&P-2
Section IV
PERFORMANCE TESTS (cont'd)
4-28. Spurious Responses (cont'd)
2. Adjust the HP 608F frequency to center the signal on the CRT. Then adjust the HP 606B frequency t place its signal
50 kHz from the HP 608F signal.
3. Set SCAN TIME PER DIVISION to 50 MILLISECONDS and adjust each signal generator's attenuator so that its
signal amplitude peaks 3 dB below the LOG REF graticule line (-43 dBm).
4. Tune the analyzer to 19.950 MHz and check for a second-order intermodulation product.
-110 dBm
5. Tune the analyzer to 10.050 MHz and check for third-order IM. Third-order products also occur at the following
frequencies: 9.900 MHz, 29.950 MHz, 29.900 MHz.
10.050 MHz
-110 dBm
NOTE
Signal generators exhibit harmonic distortion, typically about 35 dB below fundamental level.
Harmonic distortion will occur at multiples of 9.950 and 10 MHz. Care must be taken not to
confuse harmonic distortion produced by the source with intermodulation distortion produced
by the input mixer.
4-29. Residual Responses
SPECIFICATION:
Referred to signal level at input mixer*:
20 kHz to 110 MHz: <-110 dBm
20 kHz to 200 kHz: <-95 dBm.
DESCRIPTION:
Signals present on the display with no input are called residual responses. To measure residual responses, a reference
is selected so that -110 dBm is easily determined. The display is searched for residual responses under the various test
conditions called out.
1. Set the analyzer controls as follows:
RANGE MHz ................................ ................................ ................................ ................................ ................... 0-110
FREQUENCY ................................ ................................ ................................ ................................ ............... 60 MHz
FINE TUNE................................ ................................ ................................ ................................ ................. Centered
BANDWIDTH ................................ ................................ ................................ ................................ ...................... kHz
INPUT ATTENUATION................................ ................................ ................................ ................................ ......... dB
SCAN WIDTH ................................ ................................ ................................ ................................ ....PER DIVISION
SCAN WIDTH PER DIVISION ................................ ................................ ................................ ...................... 10 MHz
BASE LINE CLIPPER ................................ ................................ ................................ ................................ ..max ccw
SCAN TIME PER DIVISION ................................ ................................ ................................ ............... 10 SECONDS
LOG/LINEAR ................................ ................................ ................................ ................................ ..................... LOG
LOG REF LEVEL controls................................ ................................ ................................ ............................ -60 dBm
TUNING STABILIZER................................ ................................ ................................ ................................ ...........On
VIDEO FILTER ................................ ................................ ................................ ................................ .................. OFF
SCAN MODE ................................ ................................ ................................ ................................ .................... INT k
SCAN TRIGGER ................................ ................................ ................................ ................................ ............ AUTO
*Signal level at input mixer = Signal level at RF INPUT - INPUT ATTENUATION.
4-18
