Because wavelengths were short, even very small sonar could produce a relatively narrow beam (15° wide in typical United States sets) which gave adequate definition to control the fire of shortrange weapons, such as depth charges. After World War II, sonar frequency was reduced to improve range.
Dec 18, 2013· In the latter part of the 8th century BC, Greek merchants brought classical civilization to the trade emporiums in Tanais and Phanagoria. Gelonus was described by Herodotos as a huge (Europe's biggest) earth and woodfortified grad inhabited around 500 BC by Heloni and about the 2nd century AD Goths migrated to the Black Sea, and in the 3rd and 4th centuries AD, a semi .
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