4
Mounting Microphone and Headphone Jacks
1. Locate the mounting areas making sure that the jacks will not interfere with any aircraft control compo-
nents. (The jack contacts will expand when a plug is inserted into the jack.)
2. Drill 3/8” diameter holes for the headphone jacks.
3. Drill 1/2” diameter holes for the microphone jacks and install with the
insulating washers supplied. (see Fig. 7 )
Stereo Headphones
The ITC-404SP is designed to work STEREO HEADPHONES. Using MONO headphones could cause
damage to the intercom. If mono headphones are to be used with the intercom, either install a SPST switch
to the RING lead on the Stereo headphone jack or leave the terminal unconnected.
Cellular Phone Jack
The 2.5mm jack terminal diagram is located on page 7 and the intercom connector, J3 is located on page 8.
Auxiliary Audio Stereo Input
The Auxiliary Audio input is available for connecting a portable CD Player or other audio device to the in-
tercom system.
Push-to-Talk Switch
The ITC-404SP will accept both Pilot and Co-Pilot PTT switch installation. SPST push button switch’s can
be used with one terminal connected to ground and the other terminal connected to socket S1-7 for the Pi-
lots PTT and S1-9 for the Co-Pilot’s PTT.
Operation of the ITC-404SP
The ITC-404SP is one of the simplest intercoms available to operate, plug in the headphones, turn on the
power and start talking. It’s that easy!
With the ITC-404SP Enhanced Noise Reduction circuit, there are no squelch controls or functions to con-
tend with. Since there are no squelch function either manual or automatic, it is not necessary to kick-start
the audio with the first spoken word. Also, the missed words due to long pauses are gone. Simply talk.
Volume and Power Control
Turning the Volume control clock wise will turn on power to the intercom and increase the intercom
volume. This controls the amplitude of the headsets microphone heard by the pilot and passengers. The vol-
ume control has no effect of the auxiliary audio or the communications radio audio level.
Pilot/All Switch
The Pilot/All switch controls the audio heard by the pilot and passengers. In the ALL position, the
Pilot, Passengers, Auxiliary audio and Communication Audio can be heard by everyone.
With the switch in the Pilot position, the pilot will hear audio from the communication radio but not the
passengers or the auxiliary audio. There will be no side-tone heard by the pilot.
Headphones and ENRI
As with any intercom installation, the amount of ambient noise heard through the Passive ear cups is
dependent on the quality of the headphones. The better the Passive headphones, the better the nose reduc-
tion.
Summary of Contents for ITC-404SP
Page 9: ...NOTES 9 ...
