has learned of 14 reported malfunctions with the Motorola radio system since 2005, the same year that the city claimed to have worked out most bugs with the $62 million system. Some were minor maintenance issues, but others were far more serious:

_ March 15, 2008: Police Chief Inspector Michael Feeney said that problems with a Verizon T1 line - which ties into the Motorola system - caused a screeching sound in North Philly, making it practically impossible to hear radio transmissions. Later that same night, cops in Northeast Philly couldn't communicate with police dispatchers. The city relied on a backup radio for six hours while Verizon technicians replaced eight electronic cards, which help the system function, in City Hall and at Police Headquarters.

_ Jan. 17, 2008: Police officials said that an officer-assist call caused a citywide band to "go down for a minute."

_ Dec. 7, 2007: An electronic-card failure at a communication tower on Domino Lane in Roxborough forced police officers across the city to rely on a backup radio system and switch to two-man teams from 4:30 to 8 p.m., said Communications Inspector Thomas Lippo. "We never lost contact with them," Lippo said.

_ Nov. 13, 2007: Two undercover narcotics cops were shot in East Frankford. A Highway Patrol officer, who tended to a wounded cop and who drove him to a hospital, said that he couldn't reach anyone on his radio for 30 minutes. Another officer, who responded to the shooting from North Philly, said that she couldn't reach anyone for 10 to 15 minutes. The city attributed the malfunctions to the officers' using the radios improperly.

_ Oct. 11, 2007: A radio tower at 31st and Grays Ferry was struck by lightning, making it difficult for cops to send or receive radio messages. They relied on a backup radio system from 8:15 until 9:40 p.m., Lippo said.

_ June 28, 2007: A radio tower near Philadelphia International Airport was struck by lightning, making it difficult for cops in South, Southwest and West Philadelphia to send or receive messages, Lippo said. They relied on a backup system sporadically from 12:40 until 7:05 a.m.

_ Dec. 14, 2006: Trouble with a Verizon T1 line at City Hall forced police to rely on a backup radio system for two hours, Lippo said.

_ Sept. 11, 2006: A "multiplexer unit" went down on the T1 line at City Hall, forcing cops to rely on the backup radio system - and ride around the city in two-man teams for safety - for three full days, Lippo said.

_ Sept. 5, 2006: A Verizon T1 line near Philadelphia International Airport malfunctioned, causing brief communication problems, Lippo said.

_ March 19, 2005: Communications problems in Southwest Philly and the East Division were tied to another broken electronic card, which helps to operate the radio system, Lippo said. The backup system was used several times between 1 and 8 p.m., and even into the following day.

_ Feb. 23, 2005: Radio bands throughout the city went to the backup system for three minutes, beginning at 8:04 p.m., because of problems with area radio towers.

_ Jan. 5, 2005: A police lieutenant tried six times to use his emergency button - which should have given him 10 seconds of clear air - when he was at a quadruple-assist call in South Philadelphia, Lippo said. He wound up using another officer's radio to get his message across. *

- David Gambacorta