PS Engineering PMA7000H Installation Manual - Manual (Page 18)

PS Engineering
PMA7000H Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-780-0429 Page 2-11 Rev. 4, Dec 2012
6. Check intercom operation.
7. Check intercom Push-to-talk operation
8. Push the Com 1 Xmt select button (lower row).
9. Verify that both of the Com 1 buttons light. Verify that transmit button LED (Light Emitting Diode)
near the mic selector is not blinking. If the LED is blinking, stop testing and troubleshoot the micro-
phone PTT installation.
10. Verify proper transmit and receive operation from the copilot position, noting that the copilot PTT
switch allows proper transmission on the selected transceiver. Verify that the Com 1 Xmt button blinks
when transmitting.
11. Verify that pushing the C OM 2 button causes the button to illuminate, and the Com 2 receiver to be
heard. Verify operation on Com 1 from the pilot position.
12. Repeat for Com 2 and standard Com 3, (if installed).
13. Press and hold the Com 1 Xmt button. While holding the Com 1 button, press the Com 2 Xmt button.
This places the unit in “split Mode;” Verify that the pilot can transmit and receive on Com 1, while the
copilot transmits and receives on Com 2.
14. If the audio panel is installed with J2, pin J grounded, it is configured for duplex operation on Com 3.
Verify that the pilot headset is connected to the cellular telephone system (if installed). Verify that by
using the pilot side PTT, the pilot can transmit on the other selected radio (Com 1 or Com 2). Verify
that the Com 3 Xmt LED blinks at about twice the rate of com 1, to indicate a duplex mode. The copi-
lot has radio transmit capability in Com3 duplex mode, on the selected Com ( 1 or 2). However, he will
have Com 3 capability if the copilot hook switch is grounded.
15. Verify proper operation of all receiver sources by selecting them using the appropriate button. The but-
ton illuminates to show which source is in use.
16. Push the SPR button. Verify that all selected audio is heard in the cockpit speaker. Verify that the audio
mutes when the mic is keyed.
17. Verify that the appropriate LED in the lower right side blinks when either push to talk is keyed.
18. Verify proper Intercom system operation in the A
LL , I SO and C REW modes (see Table 3-1).
19. Verify that the audio selector panel system does not adversely affect any other aircraft system by sys-
tematically switching the unit on and off, while monitoring the other avionics and electrical equipment
on the aircraft.
2.10.2.1Marker Checkout
1. Connect a ramp generator at the antenna end of the marker coax. With the unit under test in HI sensitiv-
ity, verify that a 160  V, modulated 95% with 1300 Hz, signal will illuminate the amber (M) marker
light, and that marker audio is present in the headphones when the Marker Audio (M) push-button has
been depressed. Select SPR for speaker to verify marker audio availability on the cabin speaker. Verify
that the white (I) and blue (O) lights will illuminate within  3dB of the amber lamp, with 3000 HZ and
400 Hz applied, respectively.
2. Repeat with the unit in LOW sensitivity, with 430  Volts applied.
3. Connect the marker antenna and verify proper operation.
2.10.3 Receiver Sensitivity
Although the receiver meets FAA TSO-C35d sensitivity specifications, the sensitivity has been adjusted to
meet real world requirements (150  V and 430  V, soft). This will usually eliminate the need for the avion-
ics shop to reduce the sensitivity in the field so as to prevent early detection of the marker beacons. If your
particular installation requires more or less sensitivity, see adjustment section 2.6, and figure 2-1.