The T164-02 Combined Test Line uses the ringing voltage as a start
and provides a timed disconnect.
Rack Mounted
1010 Hz mW Tone
&#plusmn;.03 dB Stability for all Conditions
Oscillator and Balance Termination Impedance
Automatic Changeover from Tone to Balance Termination
Test Jack Provided
Tone Delay after Initial OFF HOOK
24 V or 48 V Operation Standard
The Model T164-02 is a combined test line which
provides a stable mW, 1010 Hz reference tone for an 8 to 10 second period
followed by a quiet termination.
It is designed for installation in a remote office or PBX, and provides means
for making one-way transmission and noise measurements as required for
connection appraisal surveys. The unit is available as rack mount equipment.
The T164-02 is designed for use with 101 ESS PABX or similar equipment where a
test line control lead, such as the S lead, is not available, and where a dry
circuit cannot be provided. In these cases, the call is initiated by ringing
voltage on the pair.
The T164-02 will answer a call in approximately one half of a ring cycle. Once
answered, the line circuit will remain OFF HOOK for a timed period of 16 to 20
seconds, then it will disconnect, ready for another call.
The T164-02 has a stable 1010 Hz tone generator with a nominal output of 0 dBm,
and a quiet termination of 900 ohms +2.16 MicroF, which is automatically connected
across the line when the tone is not present.
The Model T164-02 provides the following sequence of events after a call is
received:
TIMEOUT INTERVAL
16-20 SECONDS
Idle
Ring
Ring
Tone
Quiet Term
1 Sec
Trip
8-10 Sec
8-10 Sec
QUIET
1 SEC
OFF
DISCONNECT
NOTE: Above figure applies when strapped for combined (Tone and Quiet
Termination) operation. If arranged for Continuous Tone, tone would be present
for 16 to 20 seconds.
Application of the milliwatt tone is delayed 1 second after OFF HOOK to avoid
interference with any equipment which may still be in the line circuit when the
OFF HOOK condition is first established.
The milliwatt tone stays on for 8 to 10 seconds, after which it is removed and
the quiet termination is connected across the line. The circuit remains in this
state until disconnect occurs at the end of the timed period.
The T164-02 may be connected internally for continuous tone following the
initial 1 second delay.
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