Nat ASM73, Installation And Operation Manual, Page: 10 / 30

AA30-0xx Expansion Switches Manual SM73 Rev. 4.00
2.3.2 Cautions
In all installations, use shielded cable exactly as shown and ground as indicated.
Significant ground loop and noise problems may result from not following these
guidelines.
The shielding and routing of the MIC LINES used in the AA30-0xx installation is very
critical and poor performance of the aircraft audio system will result if these issues are
not handled properly.
2.3.3 Cabling and Wiring
All unshielded wire shall be selected in accordance with AC43.13-1B Change 1,
Paragraphs 11-76 through 11-78. Wire types should be to MIL-W-22759 as specified in
AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11. For
shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solder sleeves
(for shield terminations) to make the most compact and easily terminated interconnect.
Follow the wiring diagrams in Section 2.6 as required.
Allow 3 inches from the end of the wire to the shield termination to allow the hood to be
easily installed. Note that the hood is a ‘clamshell’ hood, and is installed after the wiring
is complete.
All wiring should be at least 22 AWG, except power and ground lines, which should be
at least 20 AWG. Ensure that all ground connections are clean and well secured.
2.3.4 Post-Installation Checks
2.3.4.1 AA30-013 Voltage/Resistance Checks
Check the following:
a) P101
pin <9> for +28 Vdc lighting buss voltage.
b) P101
pin <22> and <24> for continuity to ground.
2.3.4.2 AA30-014 Voltage/Resistance Checks
Check the following:
a)
P101 and P102 pins <7> for +28 Vdc avionics buss voltage.
b)
P101 and P102 pins <9> for +28 Vdc lighting buss voltage (only one required).
c)
P101 and P102 pins <22> and <24> for continuity to ground.
d)
P101 and P102 pins <11> for continuity to ground when keyed.
Page 2-2 Sep 18, 2006
ENG-FORM: 805-0107.DOT
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