What was found
IMMEDIATELY AFTER DEPARTURE, WHILE CLIMBING THROUGH 100 FT, PILOT COULD NOT CONTACT DISPATCH VIA FM RADIO AND ALSO SMELLED BURNING ELECTRONICS. DECISION MADE TO ABORT FLIGHT AND RETURN TO BASE. MX CHECKED FM RADIO FOR OPERATION, FOUND AUDIO PANEL SELECTOR SWITCH INCORRECTLY PLACED. OPERATION OF RADIO FOUND GOOD. INSPECTED FOR SOURCE OF ODOR. USING GROUND POWER SUPPLY. ALL ACFT SYS OPERATING PROPERLY. NO BURNED ELECTRICAL ODOR FOUND. ACFT GROUND RUN AND SUBSEQUENTLY CHECK FLOWN WITH NO ODORS FOUND. POSSIBLE THAT THE ODOR CAME FROM BURNING AT A LOCAL REFINERY AND NOT THE ACFT.