Studio Technologies 2A 2015 - Manual (Page 15)

Model 2A User Guide Issue 2, March 2015
Studio Technologies, Inc. Page 15
Connecting to the Telephone
Interfaces
Caution: Never install telephone wiring
during a lightning storm. Never install
telephone jacks in wet locations unless
the jack is specifically designed for wet
locations. Never touch non-insulated
telephone wires or terminals unless the
telephone line has been disconnected
at the network interface. Use caution
when installing or modifying telephone
lines.
Overview
The Model 2A contains two telephone
interfaces which can be individually con-
figured to allow connection to a telephone
line or to a standard audio signal. A tele-
phone line is designated as such if it has a
DC voltage (typically –48) associated with
it. This type of telephone line is sometimes
referred to as being a “wet” line. A standard
audio signal is one that is isolated from any
source of DC voltage. Some fax adapters
associated with cellular telephones provide
this type of “telephone” line. A standard
audio signal is sometimes referred to as a
“dry” signal. While this sounds confusing,
contemporary applications sometimes re-
fer to both types of signals as “telco.” To a
large production vehicle that pulls up to do
a 2-week golf tournament, a telco line of-
ten is one provided by the local telephone
company terminated on an RJ11 jack. To
a mobile news gathering (ENG) vehicle, a
telco signal might come from an adapter
associated with a cellular telephone which
in many cases is simply a standard audio
signal.
Some of the important features of the Model
2A’s telephone interfaces include:
Telephone Interface 1
• Telephone line or standard audio mode
select switch on back panel
• Used to receive audio only
• Receive audio can be used as program
and VOX source
• Front-panel ±8 dB receive level trim pot
• Front-panel switch allows manual an-
swer and hang-up (telephone line mode)
• Auto disconnect upon telco-provided
break in loop current (telephone line
mode)
• Front-panel operating mode and loop
current status LEDs
• 6-position modular jack allows input and
output connections for telco interface 1
and an input connection for telco inter-
face 2
Telephone Interface 2
• Telephone line or standard audio mode
select switch on back panel
• Used to receive or send audio
• Receive audio can be used as program
and VOX source
• Front-panel ±8 dB receive level trim pot
• Sends audio from either IFB channel
• Automatic answer of “ringing” telephone
line (telephone line mode)
• Auto disconnect upon telco-provided
break in loop current (telephone line
mode)