PS Engineering PMA7000B Installation Manual - Manual (Page 15)

PS Engineering
PMA7000B Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-780-0005 Page 2-8 Rev. 10, December 2012
Interface to the expansion unit is through J2, pins P (audio input from expansion unit), S (audio output to
expansion unit) and C (9 VDC expansion power).
2.5 Marker Beacon Installation
The marker beacon receiver is an option included in the PMA7000B. Non-marker (PMA7000) units can
provide audio interface with the external receiver (see section 2.5.4).
2.5.1 Marker Antenna Installation
A marker beacon antenna, appropriate to the type and speed of the aircraft, is required (not included).
Refer to aircraft and antenna manufacturer's installation instructions, as well as AC43.13-2A (or later
revision), Chapter 3, for information on proper antenna installation techniques. The marker beacon an-
tenna must be mounted on the bottom of the aircraft.
2.5.2 External Marker Lights (Marker version)
For installations that require external marker beacon lights, there are three outputs that can drive 12-Volt
lamps only. The external output lamps are driven high (typically +9 VDC 1.5 VDC unloaded, at MAX
brightness) when active. Maximum source current per lamp is 125 mA. Voltage varies with photocell
dimming.
2.5.3 Middle Marker Sense (Marker version)
A Middle Marker Sense output signal is available from the 7000B to flight control systems. This function
will not operate during the test mode. This output will go to +4.5 VDC ( 1.0 VDC) when a valid Middle
Marker signal is received. This output is J1, pin 2.
2.5.4 Marker Audio Input (non-marker version)
If using an external marker receiver, the audio input is J1, pin 21 (MKR input).
2.6 Adjustments
The PMA7000B is factory adjusted to accommodate the typical requirements for most aircraft configura-
tions. There are five adjustments however, that will allow the installer to tailor the specific functions.
Unswitched input #3 can be attenuated by adjusting VR1 accessible through the bottom of the bottom
board under the black antistatic cover, and labeled “unsw aud.”
COM 3 volume (for cellular phone volume) is adjusted with VR73, located on the bottom board, but ac-
cessible through the top board.
The unit will have to be removed from the tray to make these adjustments.