DHY-03 User Handbook
7
handset must be replaced, otherwise the line will be double terminated resulting in poorer
performance. To clear the line at the end of the call, press the line connect button. The line
connect button lamp is off in the non-connected mode and illuminated in the connected
mode. The DHY-03 is also capable of making outgoing calls via DTMF dialling by using the
serial port and sending a TEL:nnnnn command.
If the line is not connected to a valid telephone system (determined by no line voltage
present) then trying to connect is invalid. Pressing the line hold button will cause it to flash
twice quickly. If the attempt to connect is via the serial port then the DHY-03 returns an
ERR:08 error message.
Call Established
Level Setting
The DHY-03 hybrid operation is optimised for signals around 0dB. The front panel gain
switches can adjust the signal levels for both caller and sender. The default position for
these switches is receive gain (upper) fully counter-clockwise (-6dB) and the transmit gain
(lower) to be in the middle (0dB). Set the lower switch so that the bargraph normally shows
0dB (second yellow LED) with occasional peak signal levels illuminating s6db
(first red LED). If your mixing desk or source audio is only sent at consumer level then JP1
should be fitted (see Figure 2-5 or Figure 2-8).
DTMF Detection
The caller can use this feature in conjunction with auto answer to force external actions from
the DHY-03. Once again in the case of journalists ringing in a report, they can press
a key on the telephone keypad to switch on an external recorder. The key used is set by
parameter 2 (see Parameter Numbers - Function and Value). The presence of the DTMF tones
in the incoming signal for the chosen key will activate the output on the remote connector.
Integrated Disconnect Detector – Auto Disconnect
The DHY-03 can detect when a call has been dropped by the caller and can release the line.
There are a variety of ways that the central exchange can signal this to remote equipment
and the DHY-03 supports the 3 most common methods: –
.
Momentarily reversing the polarity of the signal (line reversal);
.
Momentarily shorting the tip & ring (K-break)
.
Issuing a tone to the line (tone detect).
The method chosen is initially determined by the country code selected, but this can be
overridden by changing parameter 25, serially.
Conference Calls
The DHY-03 has the ability to conference 2 calls on separate DHY-03 units together so that
you need only use 1 telco module on the mixer. These units are linked by a CAT 5 cable
(wired as shown overpage) via the RJ45 connectors on the rear of the units. The conference
calls record feature is unavailable on the DHY-03.
Note: This is not a standard CAT 5, or CAT 5 crossover, cable.
Establishing calls on both units will allow each caller to hear a mix of the clean-feed station
output and the other caller. The feed to the mixer will contain a mix of both received calls.
INTR
ODUC
TION
INTRODUCTION
1
