Low Band Problems (30 Hz To 2.9 Ghz) - HP 8560E Service Manual

Low Band Problems (30 Hz to 2.9 GHz)

1. Disconnect all inputs from the front panel INPUT 50 Ω connector.
2. Set the HP 8560E/EC to the following settings:
3. The LO feedthrough amplitude observed on the display should be
The marker will not peak search on the LO feedthrough when in a
NOTE
non-zero span. To measure the LO feedthrough amplitude with the
markers, set the span to 0 Hz and center frequency to 0 Hz. Press
ON.
4. If the LO feedthrough amplitude is within limits, but signals are low,
5. If the LO feedthrough amplitude is higher than −5 dBm (signal will
6. Check A13 Second Converter mixer diode bias at A14J19 pin 1. The
7. Troubleshoot the signal path. Refer to the power levels listed on
Chapter 11
Center frequency ...........................................................0 Hz
Span ........................................................................... 1 MHz
Input attenuation ..........................................................0 dB
between −6 and −30 dBm.
the RF path following the A8 Low Band Mixer is operating properly.
be "clipped" at top of screen) and signals are low in amplitude,
suspect a defective A8 Low Band Mixer.
bias voltage should be between −150 and −900 moved.
Figure 11-3 on page
Diagram.
Low Band Problems (30 Hz to 2.9 GHz)
604, RF Section Troubleshooting Block
RF Section
MKR
587