SET-UP and INSTALLATION
Mounting the Intercom to the Aircraft
The 403 and 403d intercoms can be mounted to the aircraft in either of the following ways:
• Standard 2
1
/
4
inch Instrument Hole Mounting
• Through-panel or Under-panel Mounting
Standard 2
1
/
4
inch Instrument Hole Mounting
To mount the intercom with standard 2
1
/
4
inch hole mount:
1. Secure the intercom to the large control panel using the two hex nuts and washers located on each
potentiometer control shaft
(Figure 2 below)
.
NOTE:
this is the only time when the potentiometer nuts and washers can be removed and replaced. Do not
remove or use them to secure the intercom to the aircraft panel or to the small rectangular control panel.
CAUTION:
the potentiometer control shafts are easily damaged after the hex nuts have been removed.
2. Attach the intercom/control panel assembly to the aircraft panel with four 6-32 non-magnetic screws.
3. Attach the
Volume
and
Squelch
control knobs to the screws, so that both knobs point to the 7 o’clock
position when rotated completely counter-clockwise.
Large
Control
Panel
Large
Control
Panel
6-32 Non-magnetic
Screws (4)
Knobs (2)
VOLUME
SQUELCH
INTERCOM
Hex Nuts & Washers
(2 each)
Figure 2
- Large Control Panel-Exploded View
INTERCOM
AIRCRAFT
PANEL
Washers (2)
Nuts (2)
Knobs(2)
6-32
Non-Magnetic
Screws (4)
Through-panel or Under-panel Mounting
The intercom can be mounted in any 5.5 inch deep, 1.2 inch by 2.5 inch space. It can be placed either verti-
cally or horizontally in or under the aircraft instrument panel or in any other accessible location in the aircraft.
For through-panel or under-panel mounting:
1. Leave the two potentiometer nuts in place on the intercom.
2. Place the small intercom control panel on the aircraft panel either vertically or horizontally
(page 2, Figure 3)
,
and use one of the drill templates shown in
(Figure 4, page 2)
to trace the location of the holes for drilling.
• For panels less than .1 inch thick, use a 9/32 inch drill bit for the controls
(use Drill Template #1 in Figure 4,
page 2,)
.
• For panels between .1 and .2 inches thick, use a 1/2 inch drill bit or punch to clear the potentiometer
nuts
(use Drill Template #2 in Figure 4, page 2)
.
Figure 2
- Large Control Panel-Exploded View
1
