Studio Technologies IFB Plus 2001 - Manual (Page 17)

Model 2 User Guide Issue 7, November 2001
Studio Technologies, Inc. Page 17
the rack adapter. Plenty of room remains
on the right side of the rack adapter,
allowing you to add custom switches,
lights, or jacks as your installation may
require.
The Model 28A Panel Adapter allows the
installation of a Model 22 and a Model 11A
gooseneck microphone in a “cut out”
made in a desk, console, or other enclo-
sure. 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
installation 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 imple-
menting your own mounting method.
Contained on both the Model 2 and the
Model 22 are standard 9-pin D-type fe-
male 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 +18Vdc
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
contains two 9-pin D-type female connec-
tors wired in parallel. This allows signals
to be easily “looped through” on their
way to the next Model 22. For short cable
runs, standard 9-pin video monitor exten-
sion 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 assem-
blies 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 Tech-
nologies, 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 unbal-
anced electret-type microphones. The +
terminal on the mic input provides current
limited 5Vdc to power the electret micro-
phone. 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 micro-
phone cable; it doesn’t carry signal.