PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010
Page 3-3
Rev. 29, Sept. 2021
3.4.4
Observer transmit selection (part number
–0400 series).
If the installation uses a dual panel, observer configuration, the crew panel serves the pilot and copilot,
while the second audio panel serves the observer.
The pilot and copilot have access to all transceivers. The observer can access any radio but the crew will
have transmit priority. If the crew selects a radio for transmit that the observer has previously selected, all
parties can transmit, but the pilot, copilot, have priority over the observer (in that order).
The crew has priority on all radios. The observer can listen to all radios if desired.
3.5
Receive Audio Selector (1)
Receiver audio is selected through 9 momentary push-button, backlit switches.
Because the microphone pushbutton selector switch controls what transceiver is being heard, you will al-
ways hear the audio from the transceiver that is selected for transmit.
The users can identify which receivers are selected by noting which of the green switch LEDs are illumi-
nated. Push buttons labeled
Nav 1
,
Nav 2
,
MKR
(Marker),
and AUX
(auxiliary), are momentary type
switches. When one of these buttons is pressed, it will place the audio in the headphone or speaker output,
and the LED will illuminate. Press the switch again and will remove that receiver from the audio.
If the aircraft is equipped with an ADF or DME, that audio is available through the AUX button.
NOTE:
On PAC24 –0500 units (Vertical) the AUX is replaced with ADF button and DME audio not present.
Buttons are labeled C1 through C5, NAV is N1, N2
3.5.1
Speaker Amplifier (4)
The 3-position "
SPR
" switch controls the distribution of the audio in the cockpit or external (public ad-
dress) speakers. In the up “SPR” position all selected audio is presented to the cockpit speaker. Unswitched
audio, (autopilot disconnect, altimeter warning, etc.) will come through the speaker regardless of the speak-
er button position.
In PA, the primary (pilot) microphone audio is routed to the PA or external speaker (J3 pin B) when the
PTT is active. The copilot mic input can continue to transmit on the selected radio.
3.5.2
Key “Click”
The PAC24 is equipped with a “click” function that provides an aural feedback to the user in addition 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.
3.6
Split Mode
The PAC24 has a flexible split mode, which allows one pilot to use one transceiver while the other can
communicate on another. There are differences in the Split Mode in a single, or a dual audio panel installa-
tion.
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, particularly on adjacent
frequencies.
PS Engineering makes no warranty about the suitability of Split Mode in all aircraft conditions.
3.6.1
Split Mode, Single panel
The split mode can be activated at any time by pressing the desired combination of XMT buttons. For in-
stance, to activate a Com 1/Com 2 split, press and hold the Com 1 button, and then press the Com 2 button
while holding the Com 1 button. This places the pilot on Com 1 and the Copilot on Com 2.