PS Engineering PMA7000M-S Installation Manual User Manual
Page 22

PS Engineering
PMA7000M-S Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-070-0012
Page 3-3
Rev. 12, Sept.2000
3.4.1.1 Public Address Function
In PMA7000MS versions above “F” serial number for the top board (2
nd
set of unit serial numbers) a public
address function was added. To access this function, a switch is installed to connect the top connector, pin
18, to ground. This places the pilot microphone on the speaker output (Pin W) when the PTT is pushed. The
copilot can continue to use the selected com radio.
We recommend that the switch transfer the audio from the cockpit speaker to a cabin speaker for public
address. This will prevent feedback.
3.4.2 Key “Click”
The PMA7000M-S is equipped with a “click” function that provides an aural feedback to the user in addi-
tion to the tactile button push. This sound can be enabled or disabled by simultaneously holding the COM 1
and COM 2 buttons in for at least 5 seconds. Any person hearing the radios will also hear the key click.
Allow at least 20 seconds between turning the key click on and off.
3.5 Split Mode
Turning the rotary switch to C
OM
1/C
OM
2 places the PMA7000M-S into "Split Mode." This places the
pilot on Com 1 and the copilot on Com 2. An example of this useful feature is when the pilot may want to
talk to Air Traffic Control, while the copilot may be speaking to Flight Watch. Although this mode has
limitations (see below) we believe you will find this to be a useful feature.
Switching to Com 2/Com l will reverse the “Split Mode” radio selection. The pilot will be on Com 2 and
the copilot will be on Com 1.
Note:
Due to the nature of VHF communications signals, and the size constraints in general
aviation aircraft, it is probable that there will be some bleed-over in the Split mode, par-
ticularly on adjacent frequencies.
PS Engineering makes no warranty about the suitability of Split Mode in all aircraft con-
ditions.
Note: Split Mode does not turn off other (Nav, ADF, etc.) selected audio to pilot. However, the copilot will only hear
the selected communications receiver.
3.5.1 Split Mode ICS
In split mode, the pilot and copilot are usually isolated from each other on the intercom, simultaneously
using their respective radios. Depressing the ICS button in Split Mode will activate VOX intercom between
the pilot and copilot positions. This permits intercommunication when desired between the crew. Pressing
the ICS button again disables this crew intercom function.
3.6 Intercom Operation
3.6.1 IntelliVox® VOX-Squelch
No adjustment of the IntelliVox® squelch control is necessary. There is no field adjustment. Through three
individual signal processors, the ambient noise appearing in all six microphones is constantly being sam-
pled. Non-voice signals are blocked. When someone speaks, only their microphone circuit opens, placing
their voice on the intercom.
The system is designed to block continuous tones, therefore people humming or whistling in monotone may
be blocked after a few moments.