General aviation pilot reported being notified that his aircraft was involved in a near miss during daylight; VMC conditions at cruise. The pilot indicated they were not communicating with ATC; in uncontrolled airspace; was not alerted by ADS-B in the aircraft; and not aware of the near miss until being contacted after the event.

Narrative

I departed ZZZ1 east bound and then turned north bound and then west bound to JVL. Approaching JVL there was a lot of traffic both inbound and outbound. After receiving the JVL ATIS; I called the tower approximately 10 miles out giving them my position and that I had the ATIS and I was inbound landing. I did not request the overhead approach as I felt they were too busy. However; the tower controller asked me if I would like the overhead approach and of course I said yes. I was cleared for the overhead with a right break; which I did. After coffee with friend; I called ground control after obtaining the current ATIS with a departure to the west to ZZZ2 for fuel. Airport was still busy as I was #4 in line for departure. Runway 4 cleared for takeoff; I was instructed to proceed west bound with a left turn. Climbing to 3000 FT MSL; I leveled off and clearing the JVL Class D tower advised me of two aircraft in the area. One was well south of my flight path proceeding south west. I had him in sight. The second aircraft was to my left proceeding north. I did not see this airplane and I did not at any time get a traffic advisory from my ADS-B; which gives me an aural warning if traffic is within 1 mile of my airplane. He passed over me; still north bound apparently descending into JVL. If he was well within a mile of me I should have received a traffic alert; but I did not. No evasive action was needed or taken. On this short flight I did not deem it necessary to notify Rockford approach en route to ZZZ2. In fact; I had already entered the frequency for their current AWOS weather and their UNICOM frequency listening for their local traffic. I continued on to ZZZ2; entered a standard left hand pattern landing on Runway XX; fueled the aircraft and continued on to ZZZ1 uneventfully. Yesterday I received a phone call notifying me of a near miss with a 300 FT separation. I then related the above info.