PM501 Operation/Installation Manual Page 6 Revision 5, Jan 2003
All
(Down position): All parties will hear the
aircraft radio reception and transmissions, inter-
com, and music. However, during any intercom
activity, the music volume automatically de-
creases. The music volume increases gradually
back to the original level after communications
have been completed.
The radio traffic will not mute the music.
NOTE
: When either the pilot or copilot PTT
is depressed, all microphones are off except for
the transmitting one.
Warranty
PS Engineering, Inc. warrants this product to
be free from defect in material and workmanship
for a period of one year from the date of installa-
tion. In certified aircraft, an FAA Form 337 must
accompany the warranty card for this warranty to
be in effect. During the warranty period, the unit
must be returned to PS Engineering, Inc. and, at
their option, it will send a replacement at no
charge. The customer is responsible for shipping
charges returning the unit to PS Engineering.
This warranty is not transferable. Any im-
plied warranties expire at the expiration date of
this warranty. WE SHALL NOT BE LIABLE
FOR INCIDENTAL OR CONSEQUENTIAL
DAMAGES. This warranty does not cover a de-
fect that has resulted from improper or unreason-
able use or maintenance as determined by us.
This warranty is void if there is any attempt to dis-
semble this product without factory authorization.
This warranty gives you specific legal rights,
and you may also have other rights which vary
from state to state. Some states do not allow the
Volume control is not affected by plugging in
other headsets.
Adjusting The Squelch Control
This VOX operated intercom keeps all mi-
crophone channels off while the pilot, copilot or
passengers are not speaking. This reduces back-
ground noise from the aircraft. Only when some-
one speaks will their microphones automatically
turn on, passing the audio through the system.
Set the Squelch control knob by slowly ro-
tating the squelch knob clockwise until you no
longer hear the engine noise in the earphones.
When the microphone 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. Regard-
less of configuration, the pilot will always hear
the aircraft radio.
ISO
(Up Position): The pilot is isolated
from the intercom and is connected to the air-
craft radios only . He will hear only the aircraft
radio reception and sidetone (only during radio
transmissions). Copilot and passengers will hear
the intercom and music but not the aircraft radio
receptions or transmissions.
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.
Revision 5 Feb 2003 Page 3 200-118-0005
Installation
The PM501 was carefully inspected me-
chanically and thoroughly tested electrically
before shipment. It should be free electrical or
cosmetic defects. Upon receipt, verify that the
parts kit contains the following:
A. Two # 4-40 Black machine screws
B. One aluminum face plate
C. Two black knobs with white lines
D. One 15 pin Sub-D female connector
with hood
C. Two connector thumbscrews
D. One hole placement template
E. One horizontal face label
F. One vertical face label
1. Drill five holes as indicated in a location
convenient to the pilot position(s).
2. Once the holes have been drilled, insert
the PM501 from behind the instrument panel
through the holes for the knobs and switch.
3. Depending on the panel thickness (<
0.040”) you may elect to use the supplied alu-
minum faceplate to provide additional support.
Place the aluminum plate over the knob shafts,
and secure with the #4-40 screws provided.
4. Next install the two knobs by pressing
them on the shafts.
5. Remove the backing from either the verti-
cal or horizontal face label, carefully align over
the knob shafts, and press on firmly.
6. To complete the installation, a wiring har-
ness must be made and routed as shown at the
back of the manual.
IMPORTANT: You must use separate
shielded cable for the microphone and head-
phone jacks. Combining these two wires WILL
cause loud oscillations and degrade the intercom
functions. The cause of the oscillation is due to
the fact that there is a much larger signal being
carried by the headphone wire than the micro-
phone wire. When these two wires are within the
same shielded cable, cross-coupling allows the
output to get back into the input, causing oscilla-
tions to occur.
If the aircraft already has pilot and copilot
headset jacks installed, you may re-use the hard-
ware. Remove all wires from the copilot jacks
and discard them. NOTE: You may elect to use
the existing pilot headset jacks as the auxiliary
jacks.
To hook the intercom into the system, sim-
ply parallel a set of mic and headphone wires
from this set of auxiliary jacks directly to appro-
NOTE: A custom wire harness can be cus-
tom made to your specifications by the
factory. Call the factory for more details.
2.620
1.600
0.720
Ø0.500
Ø0.130
Ø0.250
Hole placement diagram (NOT TO SCALE)
NOTE
:
Do not remove
the nuts from the vol-
ume and squelch controls.