The TTX-003 Transceiver comes equipped with a DAP125 capable of monitoring audio tone signals typically sent when identifying cable pairs, and detection of DSL signals without the need to make connections to the cable pair.
The DAP125 has a dual sided probe necessary to pickup signals between the Tip and Ring. The internal high frequency amplifier is designed to receive signals in the audio spectrum as well as RF signals found in DSL circuits.
577 and 987 Hz filters are used to reduce noise and aid in receiving tone when two crews are working in close proximity during restoration operations.
When two signals are similar in amplitude the Squelch feature is used to help determine which is higher. Any signal below the mark will silence the speaker so only higher level tone will be heard.
In addition to audible tone detection the TTX-003 can monitor DSL presence on a cable pair without physical contact. This feature is very useful when determining if a pair has been provisioned with DSL without POTS battery or is merely a vacant pair.