H Heuer Instruments UMDT51A, Руководство пользователя

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Testing PLC Systems
LT51 User Manual 20
Figure 4.2: Possible RF Frequency Spectrum for SSB PLC System
To measure the levels of the following 3 RF frequencies:

Tx Pilot at 499.820 kHz

Rx Pilot at 500.180 kHz

External 3.800 kHz tone at 496.200 kHz
1. [Optional] Connect the external 3.800 kHz tone from the LT51 TXa-b
terminals to the VF/AF 600 ohm input of the PLCC equipment.
2. [Optional] Press the key followed by the [f2] soft-key to set the TX
Level. This will automatically change TX Source to ‘SINE’ and output a 10
kHz signal from the TXa-b outputs.
Set the desired TX level using the Knob or Keypad, and press the
button to clear the Dialog box, or appropriate [fx] soft-key if using keypad.
Press the [f4] soft-key to set the TX Frequency to 3800 Hz using the Knob
or Keypad, and then press the button to clear the Dialog box, or
appropriate [fx] soft-key if using the keypad.
3. Press the key, then the [f2] soft-key, and set the centre frequency to
499.820 kHz, then 500.180 kHz and 496.200 kHz using the Knob or Keypad
[the 25 Hz selective BW is chosen by default].
OR
in spectral mode( ), set the centre frequency to 498.000 kHz and
display the 3 frequencies in a spectrum.
When the frequency is entered, press the button to clear the Dialog
box, or [fx] soft-key if using keypad.