Wavetek 193 Instruction Manual page 26

3-8
NOTE
Similar waveforms apply
when external signals are
used to amplitude modu-
late the main generator.
Figure 3·9. AM Operation
AUX SYNC OUT (TIL)
SYNC OUT (TIL)
AUX GEN
FUNC:
"v
AUX OUT
FUNC OUT SUPPRESSED
CARRIER:
DEPRESSED
FUNC OUT SUPPRESSED ...,-- - -
CARRIER: - -
RELEASED
MAIN GEN FUNC: AM, AUX GEN MODE: AM
2 AM CARRIER
LEVEUNULL
19
SUPPRESSED
CARRIER 18
Step Control/Connector
Setting
Depressed. Selects sup-
pressed carrier opera-
tion.
Adjusts for equal balance
of modulation envelope
peaks. Balanced peaks
ensures greatest carrier
suppression.
As an actual exercise in operation, perform steps 27
th rough 31 of table 2-1 .
3.2.9 Suppressed Carrier Operation
Operation as a suppressed carrier modulated
generator is the same as for AM operation (ref:
paragraph 3.2.8), except the main generator carrier is
suppressed (figure 3-9). The following steps
demonstrate setting up the controls for suppressed
carrier modulation. (Bold numbers are keyed to figure
3-1. Refer to paragraph 3.1 for explanations of con-
trols and connectors.)
As an actual exercise in operation, perform steps 27
through 30 of table 2-1.
Selects modulation func-
tion
Sets amplitude modula-
tion rate
7 AUX GEN
FREQNERNIER
22
8 AUX GEN
FUNC 21
Select AM.
Select the valley of the
modulation signal.
Set unmodulated output
carrier level.
Select LlM.
Setting
Select AM. FUNC OUT
decreases by 50% to
prevent waveform clip-
ping when amplitude
modulating.
Select SET CARRIER. 2 AUX GEN
MODE 20
3 AM CARRIER
LEVEUNULL 19
4 AUX GEN
MODE 20
5 AUX GEN MODE
WIDTH/LlF/LlM
20
6 AUX GEN
MODE 20
Step Control/Connector
Main Generator
FUNC 12
3.2.8 AM Operation
In amplitude modulation, the instantaneous amplitude
of the output signal varies with the instantaneous ampli-
tude of the modulation signal figure 3-9. The main
generator may be amplitude modulated by an extenal
signal (with MODE set to AUX GEN OFF) applied to the
AM IN BNC connector as well as internally modulated
by the auxiliary generator. For internal AM operation, set
up the generator as for continuous operation (refer to
paragraph 3.2.2). The following steps demonstrate
setting up the additional controls for AM Modulation.
(Bold numbers are keyed to figure 3-1. Refer to paragraph
3.1 for explanations of controls and connectors.)