Chapter 12 621
RF Section
A15 RF Assembly
A15 RF Assembly
NOTE The block diagrams for the A14 and A15 assemblies are located in
Chapter 11, Synthesizer Section.
Confirming a Faulty Third Converter
1. Perform the "IF Input Amplitude Accuracy" performance test in the
8560 E-Series Spectrum Analyzer Calibration Guide. This exercises
most of the third converter.
2. If the performance test fails, perform the manual “13. External
Mixer Amplitude Adjustment” on page 147 or the automated “6. 3rd
Amp/2nd IF Align” on page 71 of this manual.
3. If adjustment cannot be made, disconnect W35 (coax 92) from
A15J801.
4. On the spectrum analyzer, press
PRESET and set the controls to the
following settings:
Center frequency ................................................... 300MHz
Span .............................................................................. 0Hz
5. Connect a signal generator to A15J801.
6. Set the signal generator to the following settings:
Frequency ................................................... 310.7 MHz CW
Power .............................................................................. −28dBm
7. If a flat line is displayed within 2 dB of the reference level and the
performance test passed, troubleshoot microcircuits A7, A8, A9, A10,
A12, and A13.
8. If a flat line is displayed within 2 dB of the reference level and the
performance test failed, troubleshoot the 2nd IF distribution
circuitry on the A15 RF assembly.
9. Disconnect the signal generator from A15J801 and reconnect W35.
Confirming Third Converter Output
1. Connect the spectrum analyzer CAL OUTPUT to the INPUT 50Ω
connector.
2. Set the spectrum analyzer to the following settings:
Center frequency.................................................. 300 MHz
Span .............................................................................. 0Hz
Input attenuation ....................................................... 10dB
To Next Page
Loading...
Need help?
General
