ANALOG MODULATION MODE
3-55
Selecting pulse modulation
From the
Sig Gen
menu press
[Pulse Mod]
to obtain the Pulse Mod display shown in Fig. 3-54.
The [RF Level Autocal] key will only appear if the CW burst suppression mode has been
enabled in which case a temporary calibration display will appear for approximately 1.5 s
while calibration is undertaken.
Modulation can be enabled with FM but not with AM.
RF
Level
Carrier
Freq.
LOCAL
Pulse
ON/OFF
RF Level
Autocal
Wideband
FM
AM
FM
Carrier :
Freq.
RF Level :
dBm
Single Modulation Mode
Modulation ENABLED
MHz
Int Std: 10 MHz
P U L S E O N
2 700.000 0000
-144.0
ON
C1626
Φ
M
Fig. 3-54 Sig Gen menu with pulse modulation selected
The
[Pulse On/Off]
key can be used to disable or enable the pulse modulator without enabling the
RF ALC system.
The [MOD ON-OFF] key will also disable or enable the modulator; the status being shown on the
display.
With the modulation disabled using this key the RF ALC system is operating.
If the CW Burst Suppression mode has been enabled the
[RF Level Autocal]
key can be used to
recalibrate the RF output level on demand.
Pulse modulation input level
Switch pulse mod on or off with the
[Pulse On/Off]
key. When 'On', the carrier is controlled by
the logic level applied to the PULSE INPUT socket mounted on the front panel. A logical '1' (a
voltage between 3.5 and 5 V) allows carrier output, a logical '0' (a voltage between 0 and 1.0 V)
suppresses it. Turning pulse mod off effectively applies a logical '1' allowing carrier output. Note
that the input impedance is 50
Ω.