HP 8447D Operation And Service Manual page 21

Model 8447D/E/F
Page 17
PERFORMANCE TESTS
57. Distortion and Reverse Isolation (Cont.)
5
. To check reverse isolation, disconnect the oscillator and the analyzer from the amplifier, reduce
the oscillator's output level, then connect the oscillator to the spectrum analyzer.
6
. Set the oscillator's output level for a 0 dBm signal as read on the analyzer. Connect the analyzer to
amplifier INPUT; connect the oscillator to amplifier OUTPUT.
7. Read the level of feed-through directly on the analyzer; it should be below -40 dBm:
Reverse Isolation, >40 dB down: —40 dBm --—--—
58. Noise Figure
Specifications:
Noise Figure: < 8.5 dB (for 8447D PRE AMP and 8447F PRE AMP).
Noiise figure is checked at 100 MHz by inserting a known amount of excess noise into the amplifier
under test; the known noise is then compared to the amplifier's noise level with a noise figure meter.
Noise is checked at 1200 MHz using a 1300 MHz signal source and a mixer to convert the noise to
100 MHz; then it is measured with the meter.
Equipment:
Noise Figure Meter . .
VHF Noise Source . .
UHF Noise Source . .
Sweep Oscillator . . -
Double Balanced Mixers
50 ohm Termination .
Amplifier..
Power Meter ....
Adapter ......
Cable Assembly (5) .
Adapter
(2) .... .
. . . HP342A
. . . HP 34 3A
. . . HP 349A
HP 8620A/8621A
. SL 2513/2523
. . . HP 908A
. . . HP 8447D
. HP 432A/478A
. . UG-491/U
. . HP 10503A
. . UG-201A/U
NOISE FIGURE METER
AMPLIFIER
Figure 8. Noise Figure Test Setup: 100 MHz