He also warned of past false leads - such as ships detecting their own signals. Because of that, other ships are being kept away, so as not to add unwanted noise.
http://hosted.ap.org/dynamic/storie...ME&TEMPLATE=DEFAULT&CTIME=2014-04-08-08-23-41
The black boxes normally emit a frequency of 37.5 kilohertz, and the signals picked up by the Ocean Shield were both 33.3 kilohertz, U.S. Navy Capt. Mark Matthews said.
Houston said the frequency heard was considered "quite credible" by the manufacturer, and noted that the frequency from the Air France jet that crashed several years ago was 34 kilohertz. The age of the batteries and the water pressure in the deep ocean can affect the transmission level, he said.
http://hosted.ap.org/dynamic/storie...ME&TEMPLATE=DEFAULT&CTIME=2014-04-08-08-23-41
The black boxes normally emit a frequency of 37.5 kilohertz, and the signals picked up by the Ocean Shield were both 33.3 kilohertz, U.S. Navy Capt. Mark Matthews said.
Houston said the frequency heard was considered "quite credible" by the manufacturer, and noted that the frequency from the Air France jet that crashed several years ago was 34 kilohertz. The age of the batteries and the water pressure in the deep ocean can affect the transmission level, he said.