Studio Technologies 2A 2013 - Manual (Page 15)

Model 2A User Guide Issue 1, October 2013
Studio Technologies, Inc. Page 15
Connecting Telephone Lines
Words of Caution: As with any product,
installing the Model 2A requires a safety-
first approach.
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 inter-
face. Use caution when installing or modi-
fying telephone lines.
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.
Here is a review of the important features
of the Model 2A’s telephone interfaces:
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)
• Operating mode and loop current status
LEDs
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)
• Front-panel switch allows manual an-
swer and hang-up (telephone line mode)
• Operating mode and ring activity/loop
current status LEDs