HP 8447D Operation And Service Manual page 14

Page 10
Model 8447D/E/F
PERFORMANCE TESTS
55. Gain Flatness, Mean Gain, and Gain Compression (Cont.)
Procedure:
1. To measure gain flatness and mean gain, connect the equipment as shown in Figure 3. Set the
sweep oscillator for a 1.3 GHz, leveled, CW signal; set the signal level for "10 dBm out of the 10 dB
attenuator (read on the power meter).
2. Disconnect the power meter from the sweep oscillator and 10 dB attenuator. Connect the sweep
oscillator, through the 10 dB and 20 dB attenuators, to amplifier INPUT; connect the power meter to
amplifier OUTPUT. Note the power meter reading. Use this reading to calculate amplifier gain.
EXAMPLE:
"7 dBm (read in step 2) minus "10 dBm (set in step 1) plus 20 dB (read from attenuator) - 23 dB (gain)
Gain at 1300 MHz:_ dB
NOTE
Use attenuation printed on 20 dB attenuator; this may vary slightly, depending
upon frequency.
3. Tune the sweep oscillator for a maximum indication on the power meter at 1150 ±100 MHz.
Disconnect the oscillator and the power meter from the amplifier. Connect the power meter, through
the 10 dB attenuator, to the oscillator. Set the oscillator signal level for —10 dBm out of the attenuator.
4. Disconnect the power meter from the sweep oscillator and 10 dB attenuator. Connect the oscil¬
lator, through the 10 dB and 20 dB attenuators, to amplifier INPUT; connect the power meter to
amplifier OUTPUT. Calculate and record amplifier gain (as performed in step 2).
Gain at 1150 MHz:_dB
5. Measure, calculate and record amplifier gain at the following frequencies; use the procedures
outline in steps 3 and 4.
Frequency Gain
800 ±200 MHz (tune for minimum): ___.dB
350 ±100 MHz (tune for maximum): _dB
6
. Disconnect the sweep oscillator and the power meter from the amplifier. Connect the equipment
as shown in Figure 4. Set the generator/sweeper for a 10 MHz, CW signal; set the signal level for
—40 dB (read on the voltmeter).
7. Disconnect the voltmeter from the generator/sweeper. Connect the generator/sweeper to amplifier
INPUT; connect the voltmeter, with the 50 ohm termination, to amplifier OUTPUT. Note the volt¬
meter reading. Use this reading to calculate amplifier gain.
EXAMPLE:
—18.5 dB (read in step 7) minus —40 dB (set in step 6) = 21.5 dB (gain)
Gain at 10 MHz:____ dB