Ceyear 4992A, User Manual

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Chapter IV Operation Guidance
46
Section 4 Operation Guidance for Call Function
This part describes some operations of 4992A Radio Test Set in the call test.
The instrument will be used for transmission and reception in the call. When two instruments
are involved in the call, the transmitter and receiver signals can be transmitted through the antenna
or connected through the cable. Note that the corresponding carrier frequency, modulation type
and demodulation type of the transmitter and receiver should be the same.
In the call function, the audio signal received after demodulation will be automatically sent to
the audio box port so as to be heard through the audio box speaker. If the PTT switch is pressed in
the call, the MIC signal collected by this instrument will be modulated and transmitted as the
output; and if the PTT switch is released, the received signal will be demodulated and transmitted
to the audio box speaker as the output.

Window opening: four windows, i.e. RF source, modulation source, demodulation meter and
receiver setting, will pop up automatically if the [Call] hard key is pressed. The demodulation
meter window can be maximized by pressing the [Full Screen] hard key in the lower part of
the screen, as shown in Fig. 4-24.
Fig. 4-24 Call Window Display

Call setting:

Transmitter setting: the transmitter is set according to the above setting requirements of the
RF source window. The carrier frequency, modulation type, modulation frequency and
modulation degree should be set the same as those of the receiver. Generally,
“
External MIC
”
is selected as the modulation source.

Receiver setting: set the input port, demodulation type, carrier frequency and reference level
Fig. 4-23 Schematic Diagram of Call Connection
Transmission
Transmission
Reception Reception
Audio
box
Audio
box