Introduction
4
Sonifex HY-02 User Handbook
The MIC INPUT will accept 200 ohm microphone level signals and is balanced/floating with a maximum gain of 74dB. It is
suitable for a wide range of microphones and the available gain is 74 dB to 40 dB preset by the internal gain control. The
microphone channel drives the telephone line through the line limiter with similar overload conditions.
The LINE OUTPUT connection will deliver a balanced/floating low impedance signal of 0dBm from the telephone line. The
output of the digital hybrid unit is normally 0dBu from a balanced source of 50 ohms or less across the useful bandwidth
of the equipment. The bandwidth is restricted by the line conditions between 250 Hz and 4 kHz. The output stage is
capable of driving into 600 ohm loads at up to +8dBu. Termination of the output is not necessary however and direct
connection can be made into the mixer telephone return channel. The output stage has an internal present gain control
which may be set to give 0 dB signals at the output. In addition an output noise gate operates when the telephone signal
is below the noise gate threshold control. This noise gate reduces the output gain by 34 dB under no signal conditions
eliminating the affects of telephone line cross talk. The noise gate is factory set to –26 dBu to avoid interaction with the
equipment null.
Isolation of better than 28dB is created between the input and output connectors when the hybrid unit is functioning on
an exchange line.
Connect the connector labelled “DC POWER” from the back of the hybrid unit to the power supply. The power supply
creates
±
15V dc to power the electronic hybrid processor from a 230V, 50Hz ac supply. The power unit has an
overvoltage protected output and is fully isolated and totally enclosed. Earth bonding from the IEC power connector is
carried through the connection cable and multiway socket to the electronic hybrid processor unit. The earth terminal at
the rear of the equipment provides protection for the user against dangerous line fault conditions.
A remote divert switch may be connected at the REMOTES socket in order to control the LINE CONNECT switch from, say,
the telco channel of a mixing desk.
A remote divert switch may be connected at the REMOTE DIVERT socket. The connector labelled LINE INPUT will accept
0 dB line signals and is a balanced/floating input.
The earth terminal at the rear of the equipment provides protection for the user against dangerous line fault conditions.
Note : The earth bond at the screw terminal must be connected to a technical earth to ensure the safe
operation of the equipment under all line conditions.