BE-3110
27
Fig. 4-11 Adjustment Waveform Diagram 1
[Adjustment waveform diagram 1] : [Example of Key Modulation Rate (5.5 dB)]
REF 100.9 dB
µ
V
1dB/
VERTICAL
1dB/
ATT 10 dB
A_write B_blank
RBW
1 MHz
VBW
1 MHz
SWP
200 ms
1dB/div
VBW:1MHz
RBW:1MHz
SPAN:1MHz
ST:200ms
SPAN 1.000 MHz
CENTER 41.250 MHz
17. Disconnect the cables connected to IFa in and IFa out of the unit.
18. Adjust the spectrum analyzer so that the compression modulation
peak level can be seen clearly on the spectrum analyzer screen.
(Use this item as the reference level.)
19. Set the variable resistance attenuator to 0 dB.
20. Adjust control VR1 (RV1) of the RF ASSY so that the bottom
level in the compression modulation of the signal comes to the
position set in step 7.
21. Repeat the adjustments in section 4.6 and the adjustments in steps
1 to 20 in section 4.8 three times to raise the accuracy.
*1 Observe the following values when adjusting the modulation
distortion and compression distortion to facilitate the adjustments.
• Clear mode: Meter reading
• 6/10 dB mode: Noise waveform on oscilloscope
*2 The above shows one example of the adjustment waveform. Be
sure to adjust using the attenuator substitution method. Do not
perform adjustment on the screen.
Switch No.
S1
S2
S3
S4
S5
ALL OFF
ALL OFF
0
NA
D
Jumper No.
P1
P3
DE side
Not TEST side
4.9 Setting the Switches of the
LOGIC Assy
Set switches as shown above.
