HP 8340B Manual page 207

5-16. LEVELED RF OUTPUT ADJUSTMENTS (Cont'd)
Equipment
Oscilloscope
Divider Probe, 2 Required
10:1
Detector
Digital Voltmeter (DVM)
Adapters:
APC 3.5 (f) to APC 3.5 (f) (HP 8340B only)
APC 3.5 (f)
Dual Banana to BNC (f)
BNC (f)
Procedure
MODULATOR OFFSET
1. Connect the OVM to A26TP3 (MOO LVL). Preset A26R88 (MO) fully clockwise (Figure 5-53). Turn
the OUT's LINE switch ON and allow 30 minutes warm up.
2. Press [INSTRPRESET] on the OUT. Press [CW] [8] [GHz].Press [SHIFT] [METER]to bypass
the ALC circuit and allow direct control of the linear modulator circuit.
3. Adjust the front panel rotary knob (RPG) for a DVM indication of 0.00 V + 3 mV, then note the
indication in the POWER dBin display. Adjust A26R88 (MO) counter-clockwise to decrease the
POWER dBin indication by 0.2 dB.
LEVELED BIAS
4. Disconnect the DVM and connect the oscilloscope as shown in Figure 5-52.
5. Set the oscilloscope as follows:
DISPLAY
CHAN A
TRIGGER
TIME/Div
6. On the OUT, press [INSTRPRESET] [STARTFREQ] [7] [GHz] [STOPFREQ] [1] [3]
Press [SHIFT][PWR SWP]
Save this instrument state by pressing [SAVE][2].
7. The oscilloscope display should be similar to Figure 5-54. Adjust A24R12 (MIN) so that all points
on the trace are reduced to the lowest possible voltage level (i.e., maximum negative voltage).
5-102 Adjustments
Type N (HP 8341B only)
(in)
—
Clip Lead
—
[2] [0] [dBm]. Press [SWEEPTIME] [5] [0] [msec].
[-]
HP 1741A
HP 100040
HP 8473C
HP 3456A
HP P/N 5061-5311
HP P/N 1250-1744
HP P/N 1251 -2277
HP P/N 81 20-1292
CHANNEL A
0.02 V/Div DC
COUPLED
EXT. POS.
SinS
[5] [GHz].
[.]
HP 8340B/41B