4
PL (INTERCOM) CONNECTIONS
The ADX-140 provides a high-quality interface for two channels of RTS-format TW
(wet) intercom. The ADX-140 provides power supplies and four-wire to two-wire
conversion internally, so no additional hardware is required. The PL connections
are available on three male XLR connectors. The first combines PL channel 1 and
PL channel 2 in the traditional RTS two-channel configuration. The other two
channels provide one channel of wet PL and one channel of program (non-interrupt)
audio. This prevents having to use a PL channel just to provide program audio on
the second channel of the beltpacks.
Each IFB and PL power supply is individually protected for shorts and overloads,
with a front panel indication of these conditions. The PL supplies can supply current
for up to three beltpacks on PL 1 or PL 2. The IFB supplies can supply current for
two beltpacks each.
The total number of beltpacks (PL and IFB combined)
should not exceed 6 per ADX-140.
Special care has been taken in the design of the PL sections. The hybrids (two-wire
to four-wire conversion) are carefully designed to provide good bandwidth and noise
performance, as well as a high level of trans-hybrid loss. In addition there are noise
gates implemented in the dsp to provide additional quieting. Because the long-
distance portions of the intercom are transmitted via a digital path and in four-wire
format, the PL performance far exceeds what is typically achieved with two-wire
systems in terms of response, noise, distortion, headroom, etc.
TALKBACK OPERATION
The ADX-140 provides the option of using external talent talkback switches
(handheld switches or foot switches). These may be connected via the remote
connector, and enabled via menu item 15 (GPI enable). When talkback GPI 1 is
activated, MIC 1 is muted, and the mic 1 audio is routed to the MIC 3 (TB1) path.
GPI 2 provides the same function for MIC 2 via the MIC 4 (TB2) path.
See the REMOTE pinout on page 22 for connection information.
POWER
The ADX-140 may be powered in either of two ways: There is a wide-range AC
input on the rear panel (95-250 Volts, 50/60 Hz), or the unit may be powered via the
Cat5 Ethernet cable from an ADX-8000 switch/power supply.
Both methods may be used simultaneously if desired to provide redundancy.
Summary of Contents for ADX-140
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