OPERATING INSTRUCTIONS
3. Place the
EXT MODULATION
switch in the released position.
4. Connect a suitable modulating signal to the
VCG/MOD INPUT
jack on
the front panel.
5. Adjust the modulation level as described previously.
FM OPERATION
The output of the Model 4040 can be frequency-modulated, either by the
internal 1 kHz internal signal or by an external signal applied to the front
panel
VCG/MOD INPUT
jack.
Internal
1. Set the carrier frequency using the main
FREQUENCY
controls and
RANGE
switches.
2. Engage the
MODULATION ON
switch and release the
MODU-
LATION FM/AM
switch.
3. Engage the
INT MODULATION
switch.
4. The amount of deviation can be varied by rotating the
% M O D U -
LATION
control.
External
1. Set the carrier frequency using the main
FREQUENCY
controls and
RANGE
switches.
2. Engage the
MODULATION ON
switch and release the
MODU-
LATION FM/AM
switch.
3. Place the
EXT MODULATION
switch in the released position.
Figure 6. Examples of AM modulation
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