Versions
There were large numbers of versions of the system, early models were limited to a single frequency - later ones could switch between 5 frequencies.
Read more about this topic: Rebecca/Eureka Transponding Radar
Famous quotes containing the word versions:
“The assumption must be that those who can see value only in tradition, or versions of it, deny man’s ability to adapt to changing circumstances.”
—Stephen Bayley (b. 1951)