HP 8340B Manual page 163

5-9. FM ACCURACY AND FM OVERMOD ADJUSTMENT (Cont'd)
Equipment
Spectrum Analyzer
Digital Voltmeter
Function Generator
Oscilloscope
Adapters:
APC 3.5(f) to TYPE N(m) (2 required)
APC 3.5 (f) APC 3.5 (f) (8340B only)
BNC(f) to dual banana
BNC Tee
Cables:
Semi-Rigid, SMA (in) to SMA
BNC
FM GAIN ADJUSTMENT
1. Connect the equipment as shown in Figure 5-26, FM Accuracy and Overmod Adjustment Setup.
The BNC Tee should be connected directly to the OUT's FM
allow the equipment to warm up for 30 minutes.
2. On the OUT, press
[INSTRPRESET]
[CW] [1] [0] [GHzJ
[POWERLEVEL] [0] [dBm]
[FM]
Use the DOWN ARROW step key to select an FM sensitivity of 1 MHz/V (default condition).
3. Set the DVM to measure ac volts. Set up the function generator for a 100 kHz sine wave. Adjust
the function generator's amplitude for 0.16996 Vrms (measured on the DVM). You may not be able
to set the function generator's amplitude for this exact voltage so adjust the voltage as close as
possible.
4. Press [FM] on the OUT to turn FM off. Adjust the spectrum analyzer to center the OUT's 10 GHz
output (carrier frequency) on the center of the display. Select a frequency span of 500 kHz.
5. Press [FM]on the OUT to turn FM on. Adjust A23R28 FM GAIN to null the carrier (i.e., reduce the
carrier's power level as much as possible).
FM OVERMOD ADJUSTMENT
6. If the YO Loop is already disassembled, proceed to step 7.
Remove the YO Loop from the OUT and remove the cover from the A49 YO Phase Detector
assembly. In order to remove the cover on the A49 assembly, the YO Loop will need to be
disassembled. Reinstall the YO Loop and place it in the service position. Reinstall the ribbon cable
and SMB cables which were removed during disassembly.
5-54 Adjustments
to BNC (2 required)
(in) (in)
(in)
BNC. Switch the OUT to ON and
input
HP 8566B
HP 3456A
HP 3325A
HP 1741A
HP P/N 1250-1744
HP P/N 5061-5311
HP P/N 1251 -2277
HP P/N 1250-0781
HP P/N 08340-201 24
HP P/N 8120-1 840
HP 8340B/41B