DHY-03 User Handbook
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Specified Systems
The DHY-03 is suitable for connection to any exchange line forming part of a Public
Switched Telephone Network, PSTN, or a Relevant Branch system for PSTN lines or any
extension. This equipment is not suitable as an extension to a payphone. A definition of
Relevant Branch System for PSTN is given in BS6789 : Section 6.1 : 1986 Clause 2.9; including
the note to that clause.
Ringer Equivalence Number
The REN=1 marking on the rear of this equipment relates to the performance of the
apparatus when used in combination with other items of apparatus.
The REN indicates the maximum number of items that should be connected
simultaneously to the line. This equipment may be connected with series apparatus
up to REN = 4 maximum.
Accessory Ports
Barriered Ports - The Handset series connection complies with BS6301.
Accessory Ports - Mic/Line Input, Main Output, Conferencing Port, Serial Port & Remotes
Conditions
This apparatus is not designed for use under controlled conditions of temperature and
relative humidity.
Series Connection
When connected into the loop connection between the main apparatus and the PSTN, this
apparatus introduces a voltage drop at a current of 40mA of 0.300V.
The apparatus should not be used in conjunction with other series connected apparatus
such that the aggregate declared voltage drops, together with that of any relevant wiring at
40mA, exceeds 2.0 volts.
Facilities
This apparatus has been approved for use as a telephone hybrid unit (four wire to two
wire converter) and for use with a series connected simple telephone. Any other usage
will invalidate the approval of the apparatus if as a result it then ceases to comply with the
standards against which approval was gained.
Statutory Mark
Approved for connection to telecommunications systems specified in the instructions for
use subject to the conditions set out in them.
TECHNIC
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TECHNICAL SPECIFICATION