Pilot of Lancair 4 PT may have violated Class C airspace when he experienced full scale uncommanded yaw damper deflections shortly after takeoff.

Narrative

Departing DKX VFR in VMC. Experienced abnormal operation of yaw damper. Rudder was moving almost full throw both directions causing rapid heading changes. With attention diverted; probably strayed into Class C airspace around TYS without establishing communications with Approach Control. Was monitoring the appropriate frequency and heard an aircraft inbound to TYS call and perform a TCAS RA maneuver. I had a DC-9 in sight and I was well clear; below and offset to its right. I am not sure if I was the cause of the RA. Departure told the DC-9 that his traffic was at 3;700 FT and I was just passing through 3;000 FT. Hearing the communications reminded me of the Class C airspace. Corrective action was to recycle autopilot and yaw damper control while rechecking geographical position and depart the airspace. Needed better preflight planning of airspace boundaries and better scan to avoid fixation on aircraft control issues. Could have also called Departure Control as the problem developed and informed them of my problem.