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Audio Level Setting
1.
Make the connections between the Test circuit and the LT51 as in Fig. 3.1.
2.
Turn the LT51 ON. [after Reset: Ztx = 600, Zrtx = HiZ 600, TX Source =
OFF, TX Freq =10 kHz, Mode = TX-RX (4W)]
3.
Press the
LT51 RTX (input) impedance is now 600 terminated.
4.
Press the
Use the knob to set the span to 4.5 kHz.
5.
Press the
Hz, using the Knob or Keypad, and press the
box, or appropriate [fx] soft-key if using keypad.
6.
Press the [f2] soft-key to set the TX Level. This will automatically change
TX Source to 'SINE' and output a 0 dBm, 1000 Hz signal from the TXab
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.
7.
Repeat for different levels at 2W / 4W interfaces.
8.
The display will show the received level and frequency over the 4.5 kHz BW
at the LT51 RTXab input terminals. Press
(Numerical) to toggle between displays of the signal.
LT51 User Manual
button, then the [f2] soft-key to set Input to 'Term'. The
key, followed by the [f1] soft-key to set the frequency Span.
key followed by the [f4] soft-key to set the TX Freq to 1000
Testing VF-PCM Multiplexers
button to clear the Dialog
(Spectral) or
12
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