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Old April 12th 09, 02:19 PM posted to rec.aviation.homebuilt
Edwin Johnson
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Posts: 31
Default troubleshooting com's transmission

On 2009-04-12, jan olieslagers wrote:
On my first cross-country solo, I observed everybody was clearly
readable by everybody - except nobody could understand ME clearly.
The radio on the club plane is an Icom A200, quite common I believe and
not too bad quality though it is on the cheap side. But I can't imagine
my poor transmission was due to the radio so next suspect is the
antenna, in comes the buzzword "SWR" . Is there a published procedure


When you say 'couldn't understand', do you mean they could hear you but
it was unintelligible? If that's the case, the audio portion is probably at
fault - microphone (try another microphone or headset) itself or loose
connections, if an audio panel in the plane, problems in that, audio
problems in the radio itself, wiring associated with any of the above.

Avionics antennas are built to interface at 50 ohms to the radio, so no
tuning or anything needs to be done if installed correctly. Loose cables or
ground in the cables (shielding) would cause SWR (standing wave ratio)
problems, but if a contact was intermittent you would probably hear static.
SWR problems would degrade slightly the received audio and definitely effect
transmitted, but the effect would be reduced output, not unintelligibility.

Probably first thing to check is microphone (headset) and connections,
trying another to see if that one works fine.

....Edwin
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"Once you have flown, you will walk the earth with your eyes
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