Narrative:

During taxi to the run up area at the approach end of runway 34 at mev; I heard minden area traffic on the radio. I decided to listen to the destination AWOS on the same radio; thus switching the CTAF frequency to standby. In order to hear the AWOS; I had to pull the squelch button out. When I pushed the button back in; I could no longer hear the AWOS. As a result; I did not realize that the CTAF frequency for mev remained in standby. When I departed runway 34; I first transmitted my intentions (on the wrong frequency); then looked for departing traffic on runway 30. I did not see or hear the aircraft departing runway 30 until his shadow passed overhead. I looked down at my radio; saw my mistake; and switched frequencies in time to hear the other pilot asking if I was on frequency. He stated that I passed 'right below' him. Presumably; he needed to take evasive action. There was no contact. This incident would have been prevented had I not neglected to set the CTAF frequency to active on my radio. At the time of the incident; I was well rested; well hydrated; and not distracted by issues outside of flying. I have over 300 hours in the airplane in question; and am very familiar with the layout and function of the radios.

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Original NASA ASRS Text

Title: A pilot departed MEV Runway 34 without the local CTAF frequency selected and had a near miss with an aircraft which had just departed Runway 30.

Narrative: During taxi to the run up area at the approach end of Runway 34 at MEV; I heard Minden area traffic on the radio. I decided to listen to the destination AWOS on the same radio; thus switching the CTAF frequency to standby. In order to hear the AWOS; I had to pull the squelch button out. When I pushed the button back in; I could no longer hear the AWOS. As a result; I did not realize that the CTAF frequency for MEV remained in standby. When I departed Runway 34; I first transmitted my intentions (on the wrong frequency); then looked for departing traffic on Runway 30. I did not see or hear the aircraft departing Runway 30 until his shadow passed overhead. I looked down at my radio; saw my mistake; and switched frequencies in time to hear the other pilot asking if I was on frequency. He stated that I passed 'right below' him. Presumably; he needed to take evasive action. There was no contact. This incident would have been prevented had I not neglected to set the CTAF frequency to active on my radio. At the time of the incident; I was well rested; well hydrated; and not distracted by issues outside of flying. I have over 300 hours in the airplane in question; and am very familiar with the layout and function of the radios.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.