PS Engineering PM501 - Manual (Page 4)

PM501 Operation/Installation Manual Page 4 Revision 7, Feb 2008
sette player, etc.) can be connected to the PM501. You
may want to install a ⅛" connector (not provided)
somewhere in the panel so that you can easily connect
an entertainment device.
The entertainment will be automatically muted
when the ICS becomes active. The “Soft Mute™” fea-
ture slowly returns the music to full volume when the
ICS is quiet. NOTE: Aircraft radio reception DOES
NOT mute the entertainment.
External Push to Talk Installation
Part of the installation includes the installation of
PTT (Push To Talk) switches that allow the use of
your aircraft communications radio for transmissions.
There are three configurations that can be used.
You select the case that best fits your installation re-
quirements.
NOTE: Only the person who presses their PTT
switch will be heard over the radio.
CASE I
PTT built into the pilot and copilot yokes
Simply install the plugs from the headset into the
aircraft headphone jacks. Use the yoke mounted PTT
to transmit. No other action is required.
CASE II
Built-in PTT on the pilot side only, but co-
pilot transmit capabilities desired.
This configuration requires a modified external PTT
plugged into the copilot's mic jack. See Appendix A
for modification details. When the copilot's PTT is
depressed, this activates an intercom relay that
switches the mic audio input to aircraft radio to the
copilot.
CASE III
No built-in PTT switch at all
If there is no built-in PTT switch at all, an external,
properly modified PTT switch is required. Both the
pilot and copilot may use an external PTT. (See Ap-
pendix A.)
OPERATING INSTRUCTIONS
With the installation complete, turn the PM501 on
pressing the volume control knob (left knob). This also
engages the automatic fail-safe system.
Adjusting The Volume
The volume control knob adjusts the loudness of
the intercom and music for all headsets. Turning the
control clockwise increases the audio. Many headsets
have volume controls on them. If it becomes necessary
to reduce the volume for an individual passenger, the
three others should be set at maximum, and the unit
volume set for a comfortable level. The individual can
then reduce their volume accordingly.
The radio volume is not affected for the by the
PM501 Volume Control. This gives added flexibility
for communications requirements. Note: Unit volume
is not affected by plugging in other headsets.
Adjusting The Squelch Control
This VOX operated intercom keeps all micro-
phone channels off while the pilot, copilot or passen-
gers are not speaking. This reduces background noise
from the aircraft. Only when someone speaks will their
microphones automatically turn on, passing the audio
through the system.
Set the Squelch control knob by slowly rotating
the squelch knob clockwise until you no longer hear
the engine noise in the earphones. When the micro-
phone is positioned properly near your lips, normal
speech levels should open the channel. When you stop
talking, there is a delay of about a second before the
channel closes. This prevents closure between words
and eliminates choppy communications.
Mode Select
The center switch is a 2- position mode switch
that allows the pilot to tailor the intercom function to
best meet the pilot's needs. Regardless of configura-
tion, the pilot will always hear the aircraft radio.
ISO (Up Position): The pilot is isolated from the
intercom and is connected to the aircraft radios only .
He will hear only the aircraft radio reception and side-
tone (only during radio transmissions). Copilot and
passengers will hear the intercom and music but not
the aircraft radio receptions or transmissions.
PM501 Front Panel Controls
Volume
Control
CW to
Increase
VOX Squelch
Control CW to
increase amount of
voice necessary to
open
Mode
Switch
NOTE: In the event of a power failure to the PM501,
or if the power switch is turned off, the copilot will not
hear the aircraft radio. Only the pilot is connected to
the aircraft radio.