Specifications
PS Engineering 
PMA8000B Audio Selector Panel and Intercom System 
Installation and Operator’s Manual 
200-890-0100  Page 3-3  Rev. 13, Dec. 2009 
In  ISO  intercom  mode,  when  the  PMA8000B is  in  the  TEL  mode,  the  pilot position  is  in  the "Phone 
Booth." Only the pilot will hear the telephone, and only he will be heard. He will also have access to Com 
1 or 2, and will transmit on that radio using the PTT. All selected audio is provided to the pilot.  
NOTE 
Because the cell-phone uses an intercom circuit, all stations  on that circuit will lose intercom capabi lity 
when the cell phone is in use. 
3.4.1  Cell phone Sidetone 
As  shipped  from  PS  Engineering, the  PMA8000B  does  NOT  provide  cellular  telephone  sidetone  (the 
user’s  voice  fed  back  to  the  headset).  Some  cell  phones  do  not  provide  sidetone.  In  PMA8000B  MP3 
Avidyne audio panels above serial number  W04748, Telephone sidetone can  be enabled by  pressing the 
TEL and ADF buttons  for more than  one second.  For  units with serial  number W04747 and below,   an 
internal modification can be made that will allow the PMA8000B to provide sidetone. Contact PS Eng i-
neering for more information. 
3.5  Speaker Amplifier (5)  
The  SPR  in  the  lower  right  section  stands  for  speaker.  This  switch  will place all selected audio on the 
cockpit speaker when this switch is selected. Except for the unswitched audio, the speaker amplifier is not 
active in the "Split Mode”. 
Unswitched  audio,  (the  inputs  dedicated to autopilot disconnect,  altimeter  warning, etc.)  will come 
through the speaker regardless of the speaker button position. 
Depending on installation, important audio annunciations such as radar altimeter or autopilot disconnect 
will  come over  the speaker  even  if it is not selected, while other  unswitched,  but muted inputs,  such  as 
GPS alerts, will only be present if the SPR button is selected. Consult your professional avionics installer 
for these important configuration details. 
3.5.1.1  Public Address Function 
To access PA function, press the Mute and SPR buttons simultaneously. The pilot 
microphone will be heard on the speaker when the pilot PTT is used. The copilot 
can continue to use the selected com radio while the pilot will now be heard 
over  the  speaker.  During  Public  Address,  the  Mute  and  SPR  buttons  will 
flash. To exit PA mode, push Mute and SPR again. 
3.6  Marker Beacon Operation (10) 
The Marker Beacon Receiver uses visual and audio indicators to alert you when the aircraft passes over a 
75 MHz transmitter. 
The Blue lamp, labeled “O”, is the Outer Marker lamp and has an associated 400 -Hertz 'dash' tone. The 
lamp and tone will be keyed at a rate of two tones/flashes per second when the aircraft is in the range of 
the Outer Marker Beacon. 
The Amber lamp, labeled “M”, is the Middle Marker  lamp and is coupled with a 1300 Hertz tone. It is 
keyed alternately with short 'dot' and long 'dash' bursts at 95 combinations per minute.   
The White lamp, labeled “I”, is the Inner marker and has a 3000 Hertz 'dot'  tone. The lamp and tone will 
be keyed at a rate of six times per second. 
The audio from the Marker Beacon Receiver can be heard by selecting the "MKR" push-button switch. To 
adjust the volume level, there is a service adjustment located on the top of the unit.  
A pushbutton is used to set the receiver sensitivity and to test the indicator lamps mute the marker audio.   
Use  "HI"  sensitivity  initially.  This  allows  you to  hear  the outer  marker  beacon  about a  mile  out.  Then 
touch  the  smaller  MKR  button  to  switch  into Low Sensitivity mode. “LO” sensitivity gives you a more 
accurate  location  of  the  Outer  Marker.  Holding  the  MKR  button  for  one  second  activates  marker  test 
lamp, labeled "T/M" and illuminates all three lamps simultaneously to assure the lamps (intern al and ex-










