Mic/Audio wiring
Posted: Fri Feb 17, 2012 8:39 pm
All,
Wiring the Mic and Headphone Jacks:
The Mic line is about .25 volts and the Audio is up to 4 volts. Try to keep the Mic wires away from noise makers wires. ( ant. leads, strobes wires ) Best to use Shelded 22/24 gage wire.
Use a "SINGLE POINT GROUND" for the Radio/Intercom Audio low/gnd. wiring near the Radios.
The shields all run to another ground. ( you don't want the noise on the shields getting into the Audio grounds )
The Audio shields are grounded on one end only, near the Radios, and are open (not grounded) at the jack end.
The Audio jacks should float, Not attached to aircraft metal ( this would ground the jack and the Audio Low ). Mount the jacks in plastic, fiberglass to keep the audio low from being ground at the jack end. ( the jack base is audio low) If you ground at both ends you can get a "Ground Loop" and this can put noise on your Mic lines. Headphones/Speaker Audio lines being up to 4 volts are not the problem that the Mic line are.
Hope this helps,
Chuck R176
N225PC
Charles Bailey
Rebel N225PC
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Wiring the Mic and Headphone Jacks:
The Mic line is about .25 volts and the Audio is up to 4 volts. Try to keep the Mic wires away from noise makers wires. ( ant. leads, strobes wires ) Best to use Shelded 22/24 gage wire.
Use a "SINGLE POINT GROUND" for the Radio/Intercom Audio low/gnd. wiring near the Radios.
The shields all run to another ground. ( you don't want the noise on the shields getting into the Audio grounds )
The Audio shields are grounded on one end only, near the Radios, and are open (not grounded) at the jack end.
The Audio jacks should float, Not attached to aircraft metal ( this would ground the jack and the Audio Low ). Mount the jacks in plastic, fiberglass to keep the audio low from being ground at the jack end. ( the jack base is audio low) If you ground at both ends you can get a "Ground Loop" and this can put noise on your Mic lines. Headphones/Speaker Audio lines being up to 4 volts are not the problem that the Mic line are.
Hope this helps,
Chuck R176
N225PC
Charles Bailey
Rebel N225PC
Do You Yahoo!?
Yahoo! Mail Personal Address - Get email at your own domain with Yahoo! Mail.
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