Studio Technologies IFB Plus 2005 - Manual (Page 14)

Issue 8, December 2005 Model 2 User Guide
Page 14 Studio Technologies, Inc.
in a desk, console, or other enclosure. Refer
to Figure 3 for a mechanical drawing of the
panel adapter and the required mounting
hole size.
A custom Model 22 installation is any in-
stallation where you devise the mounting
method! Refer to Figure 4 for a mechani-
cal drawing showing the dimensions of the
Model 22. This will assist you in implement-
ing your own mounting method.
Contained on both the Model 2 and the
Model 22 are standard 9-pin D-type female
connectors. A “straight through” cabling
scheme links the units together, with pin
1 connected to pin 1, pin 2 to pin 2, etc.
Shielded cable is required as the two audio
buses linking the Model 22s to the Model
2 are unbalanced. The shield should be
connected to pin 1 on the 9-pin plugs. For
reference, the following chart displays the
signals associated with the access station
connector:
Pin # Function
1 Common/Shield
2 Interrupt Audio, CH1
3 Interrupt Audio, CH2
4 +18 Vdc
5 Interrupt Control, CH1
6 Interrupt Control, CH2
7 Lamp Voltage, CH1
8 Lamp Voltage, CH2
9 Monitor Speaker Mute Control
For ease of installation, each Model 22 con-
tains two 9-pin D-type female connectors
wired in parallel. This allows signals to be
easily “looped through” on their way to the
next Model 22. For short cable runs, stan-
dard 9-pin video monitor extension cables,
commonly used with personal computers,
are an inexpensive and readily available way
to link a Model 2 with a Model 22. Ensure
that any cable assemblies you purchase use
shielded cable, with the shield connected at
pin 1 of both plugs.
For best performance, a maximum total
cable length of 500 feet should be used to
link Model 22s to the Model 2. Minimizing
the cable length reduces the total exposure
the unbalanced audio buses have to noise
pickup, etc. Cable runs longer than 500
feet are possible but should be carefully
checked for correct operation.
The Model 22 Access Station contains
several configuration switches that must be
set. The input select switch allows the unit to
be set for a mic or a line-level input. In most
cases the Model 11 gooseneck microphone,
available from Studio Technologies, will be
used with a Model 22. Setting the switch
to the mic position activates the mic input
terminals. The mic input is configured only
for use with unbalanced electret-type mi-
crophones. The + terminal on the mic input
provides current limited 5 Vdc to power the
electret microphone. Don’t use a dynamic
microphone as damage may occur. The
– terminal is connected to the microphone’s
low signal lead. The connection marked
SHLD is intended for the shield wire of the
microphone cable; it doesn’t carry signal.
The Model 11A Gooseneck Microphone is
an unbalanced electret type, requiring an
external source of DC power. The micro-
phone utilizes a 3-conductor ¼-inch plug
for interconnection. The tip lead brings DC
power to the microphone, as well as hav-
ing microphone audio superimposed on it.
The ring lead is microphone common. The
sleeve lead is a shield connection.
Included with the Model 11A is a mounting
hardware kit. Included with the kit is a
3-conductor ¼-inch jack used to mate with
the microphone’s plug. At the factory a
3-conductor wiring harness assembly is