1b-46
Operation Reference
Function
6. 1 kHz + EXT DC
Press
1 kHz + EXT DC to configure the MOD INPUT/OUTPUT port as a dc-coupled input for
modulating the carrier along with the internal 1 kHz source.
(Refer also to "3. EXT AC EXT DC" for further information about operation and acceptable
ranges.)
NOTE 1 kHz + EXT AC, 400 Hz + EXT DC, and 400 Hz + EXT AC are available only
via GPIB.
Setting the Modulation Level When modulating with both an internal and external
source, the level of the external source should not exceed 0.5 V peak or 0.5 Vdc. This level
will provide one half of the displayed modulation. To set modulation to the level you desire,
set the displayed modulation to two-thirds of the desired setting. The external source, set
to 0.5 V peak or 0.5 Vdc, will provide the additional one-third of the desired setting
(one-half of the instrument’s setting).
For example, to set up the modulation for 3 kHz of FM deviation, set the instrument for 2
kHz of FM. The external source, set to 0.5 V peak, will provide another 1 kHz of deviation.
If the external source is set to less than 0.5 V peak, the modulation level provided by the
external source will be less than one-half of the displayed modulation. The following
equation may be helpful for determining the appropriate modulation level setting for the
instrument when the level of the external source is less than 0.5 V.
Where:
• A = Actual modulation level
• E = External source level
• D = Displayed modulation level
For example, to set up for 3 kHz of FM deviation with an external source set
to 0.3 V peak, the instrument’s displayed modulation level would be:
7. MOD INPUT/OUTPUT
This port outputs a 1 Vpk (into 600 ohms) audio tone when an internal modulation source
is selected. When an external modulation input is selected (
EXT AC, EXT DC or 1kHz+EXT
DC
), it provides the input for a 1 Vpk (into 600 ohms) audio source. (Refer to the preceding
table for acceptable frequency ranges.)
E+
------------
=
0.3 V+
--------------------- 2.3 kH
=
To Next Page
Loading...
Need help?
General
