PS Engineering PM1000 - Manual (Page 4)

PS Engineering Incorporated
PM 1000 FAA TSO Approved Intercom
Installation and Operation Manual
200-190-0002 7 Rev. 2, Jan. 2001
PM1000 was designed in an interference -protected chassis and has internal filter capacitors on all input
lines.
Ground loop noise occurs when there are two different return paths for the same signal, such as airframe and
ground return wire. Large cyclic loads such as strobes, inverters, etc., can inject audible signals onto the
airframe return path. Follow the wiring diagram very carefully to help insure a minimum of ground loop
potential. Radiated signals can be a factor when low level mic signals are bundled with current carrying
power wires. Keep these cables separated.
Insulating washers are required on all mic and headphone jacks to isolate them from aircraft ground. The use
of a conductor instead of a shield for ground return eliminates these ground loop paths.
2.4.2 Power Requirements
The PM1000 was designed to work with 12.8 to 27.5 volt DC negative ground systems. The PM1000 must
be externally protected with a one ampere (1A) circuit breaker or fuse.
2.4.3 Auxiliary Input
An entertainment device can be connected to the PM1000. Install a " stereo jack convenient the pilot to
connect the entertainment device into the system.
A muting system is incorporated in the PM1000 that will mute the music during intercom activity only. Note:
The radio will not mute the music.
WARNING: Local oscillators and other internal signals from CD or radio equipment can cause undesired
interference with VHF navigation and communication equipment. Before takeoff, operate the entertainment
device to determine if there is any adverse effect on aircraft systems. If any unusual operation is noted in
flight, immediately switch the entertainment device off.
2.4.4 Optional accessories
The PM1000 can be interfaced to optional expansion units (11918, 11918R) to add additional capabilities,
such as a crew mode. The interconnect is shown in Appendix D. Because these modules are not TSO-
approved, we recommend that the FAA-approved PM1000II, part number 11920, with crew, be used instead
of the PM1000, in new installations, if these functions are desired.
2.4.5 External PTT hook-up
Part of the installation includes the installation of PTT (Push To Talk) switches that allow radio
transmissions from pilot and copilot positions.
There are three configurations that can be used. You must select the case that best fits your installation.
NOTE: Only the person who presses their PTT switch will be heard over the radio.
CASE I
PS Engineering Incorporated
PM 1000 FAA TSO Approved Intercom
Installation and Operation Manual
200-190-0002 8 Rev. 2, Jan. 2001
The PTT is built into the pilot and copilot yokes
Simply install the plugs from the headset into the aircraft headphone jacks. Then use the yoke mounted PTT
to transmit. No other action is required.
CASE II
Built in PTT only on the pilot side
This configuration requires a modified external PTT switch plugged into the copilot's mic jack. (See
Appendix A) When the copilot's PTT is depressed, this activates an internal relay that switches the mic audio
to the aircraft radio from the pilot to the copilot.
Case III
No built in PTT switch at all.
Two built-in PTT must be installed or two external, modified PTT switches will be required for both the pilot
and copilot. Modifications to the PTT may be required. (See Appendix A)
2.5 Post installation checkout
After wiring is complete, verify power is ONLY on pin 14 of the connector, and airframe ground on pin 1.
Failure to do so will cause serious internal damage and void PS Engineering's warranty.
1. Apply power to the aircraft and avionics.
2. Plug headsets into the pilot, copilot and passenger positions.
3. Verify that the pilot position can transmit and receive with the PM1000 in the OFF position (left
hand volume knob fully counterclockwise).
4. Rotate the pilot volume clockwise, about half way. Verify that the green Power light comes on.
5. Verify that the pilot can transmit and receive on the com transceivers.
6. Verify proper intercom operation for pilot and copilot. For more information, consult Section III.
7. Verify proper transmit and receive operation on the copilot position, noting that the copilot PTT
switch allows proper transmission on the selected transceiver.
8. Verify proper Intercom system operation in the ALL and ISO modes.
9. Verify that the intercom system does not adversely affect any other aircraft system by systematically
switching the unit on and off, while monitoring the other avionics and electrical equipment on the
aircraft.