Filter
Top Products
Adjustment Procedures
5-44
2715 Spectrum Analyzer Service Manual
Use the following procedure to adjust C21, C22, C23, C24, R63, R59, and L11
on the Video Demod board:
Test Setup. Connect instruments as follows:
H Test equipment required:
PAL/NTSC Signal Generator
CATV Modulator
Test Spectrum Analyzer
Tracking Generator
H Select the following settings on the test instruments:
Test Spectrum Analyzer
Center Frequency 100 MHz
Span/div 5 MHz
Reference Level --20 dBm
Vertical Scale 10 dB/div
Resolution 5 to 1 MHz
Test Tracking Generator
Output Level --20dBm
H Mount video demod board on extender board.
H Remove the connectors to the video demod board 110MHz OUT and
110MHz IN.
H Connect the output of the tracking generator to the RF Input of the test
spectrum analyzer using two cables connected together with an SMB
connector. These cables will later be connected to the Video Demodulator
board (next step).
The test spectrum analyzer display should be a nearly flat line near the top of
the screen (reference level). Adjust the output level (fine) of the tracking
generator to position the trace at the test spectrum analyzer reference level
(top of screen) over the frequency range of 105 MHz to 115 MHz.
H Connect the output of the tracking generator to the Video Demod board
110M IN connector. (This connector is an SMB connector and will require
an adapter cable.)
H Connect the TP110M (SMB connector) from the Video Demod board to the
test spectrum analyzer’s R F input.
Video Demod
Adjustment Procedure