cting on several interference complaints from amateur radio operators in California, the US Federal Communications Commission has issued a warning to a radio operator who has a long history of unlicensed, disruptive and illegal transmissions on a local repeater.

The FCC sent a notice of unlicensed operation in late May to Jack Gerritsen of Bell, California, saying that in March, agents with direction-finding equipment had verified reports of his 2-meter transmissions on a local repeater. The FCC said that agents heard him make statements over the air, using the phrase "Jack is back," identifying himself.

Over the past two decades, Gerritsen's encounters with the the legal system and FCC have landed in him court -- and prison. He received a one-year sentence in 2000 following his conviction in state court of interfering with the highway patrol's radio system. Upon his release, he took and passed his Technician level exam, receiving the amateur radio callsign, KG6IRO. The FCC revoked the license grant days later, in November 2001, after realizing Gerritsen had been convicted of public safety interference and that the license was granted mistakenly. According to various reports, he remained an on-air presence despite that. FCC records show he was later sent a forfeiture order of $21,000 for interfering with Coast Guard Auxiliary Communications with a sailing vessel in distress.

He was convicted in September of 2006, at the age of 70, for malicious interference with radio and unlicensed transmissions. He was fined and sentenced to seven years in prison.

The latest notice from the FCC, dated the 28th of May, gives him 10 days to respond and orders him to immediately halt all transmissions.