A voltmeter is helpful in determining if your inputs are “wet loops” or dry lines. Wet loops typically carry -48V DC when measured off-hook. Wet loops are used to connect to your telecom provider, to your PBX, or to analog phone extensions. Dry lines such as headsets, radios, microphones and speakers carry audio, but no DC signaling voltage.
After you’ve determined a line type (either wet-loop or dry line), select a recording trigger: either Loop Start or VOX. Outside wet loops and inside analog extensions normally use Loop Start signaling. All dry lines use VOX signaling to trigger recording.
VOX Recording for Dry Lines
To bridge a dry line using Voice Operated Switch (VOX):
• Note: VOX mode is used for dry lines (lines that do not carry signaling voltage). Examples are handset connections, headsets, radios, microphones and speakers.
• Use a punch-down block, handset Y connector, breakout box, or RJ- 11 octopus cable to connect each line (two twisted wires) to the logger. Each of the logger inputs connects in “bridge” fashion across the existing wiring.
• Verify that the line audio level is within telecom specifications. Peak level should not exceed +3dBm. Gain controls should be set so that recording levels do not exceed 0dBm. Use Level Boost only if the input level is below -20dBm. If the VU meter peaks, the line level is too high. Reduce it using the manual gain controls, turn off Level Boost, and/or switch Auto Level on.
• Use Level Boost for handsets, microphones, and low-level signals only.
• Rename the line label by clicking on the line name. Type the new name and press Enter. For example, a handset tap or analog extension connected to LINE 01 might be renamed “Support Desk.”
• Set the line configuration mode to VOX by clicking on the line mode.