5-16.
LEVELED RF OUTPUT ADJUSTMENTS (Cont’d)
HIGHEST
PEAK ADJUSTED
FOR MINIMUM
HEIGHT
8. On the OUT, press [INSTRPRESET] [SHIFT][CF] and enter [2] [0] [0]
[MHz]
for a CW step size
of 200 MHz. Press [SWEEPTIME] [5] [0] [msec].Press [SHIFT][PWRSWP] to decouple the RF
attenuator and ALC, and enter
[-]
[2]
[0] [dBm].Press [PWRSWP] [4] [0] [dBm]and [AM]
to turn
the AM on. Press [CW][8]
[GHz].
This puts the OUT in power sweep from —20 to +20 dB at any
frequency selected.
Save this instrument state by pressing [SAVE][1].
9. Preset A24R1 (OFF A) (Figure 5-53),
A24R2 (OFF B), A24R5 (X2C), A24R8 (X3C), and A24R11
(X4C) controls fully counter-clockwise.
10. Set the oscilloscope as follows:
DISPLAY
CHOP
CHAN A
0.05 V/Div DC COUPLED
CHAN B
0.05 V/Div DC COUPLED
The oscilloscope display should look similar to Figure 5-55.
LEVELED POWER SRO BIAS ADJUSTMENT
11. Adjust A24R1 (OFF A) for optimum display as shown in Figure 5-55, Waveforms A, B, and C.
12. On the OUT, press [CW] [1] [3]
[GHz].
Adjust A24R2 (OFF B) for optimum trace as shown in
Figure 5-55, Waveforms A, B, and C.
13. On the OUT, press [CW] [1] [0]
[GHz].
Adjust A24R5 (X2C) to minimize the MOD LEVEL voltage
(Channel A) at the start of the power sweep and keep the MOO LEVEL power sweep trace straight
with no step or bows as it sweep up (see Figure 5-55, Waveforms 0 and E).
Figure 5-54.
Oscilloscope Display at A26TP3 MOD L VL with no Squegging
5-104
Adjustments
HP 8340B/41B