Vdc And Idc When Off-Hook, Level Measurement - H Heuer Instruments UMDT51A User Manual

VDC and IDC when off-hook, level measurement

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
the line connected to the RTXab terminals. The interface Mode is
automatically set to RTX (2W).
4. The DC voltage and current through the 600 termination is displayed.
5. If connected to the PSTN, dial DTMF digits using the keypad to make a
connection.
While TX displays "TALK", use the hands-free telephone to transmit &
6.
receive speech from the line connected to the RTXab terminals.
7. Press the
and transmit a tone to the line connected to RTXab, during Loop-hold.
Press the [f2] & [f4] soft keys to set the TX Level & Freq using the Knob or
Keypad, and press the
[fx] soft-key if using keypad.
8. Press the
terminals.
LT51 User Manual
key to go off-hook (Loop-hold) or DC terminate (with 600)
key followed by the [f3] soft-key to set TX source to 'SINE'
button to clear the Dialog box, or appropriate
key, or to make level measurements at the RTXab
Testing VF-PCM Multiplexers
18