N-2 was similar in heterodyning scheme, but in discrete transistorized " plug-in unit " architecture, while N3 used the same frequency plan but a scheme of using single sideband with a different voice channel on each side of the carrier, a technique first seen on the 16 channel Type " O " open wire short haul carrier of the 1950s.
42.
While 0-0.75 MHz region has two side bands, the region beyond 1.25 MHz has only one side band . ( i . e ., 0-0.75 MHz region is double sideband and the region beyond 1.25 MHz is single sideband ) Thus, the level of the demodulated signal in 0-0.75 MHz region is 6 dB higher than the level in the region beyond 1.25 MHz.
43.
By filtering out unnecessary portions of the radio signal, the mechanical filter ( a kind of " bandpass filter " ) allows the use of a very stable, precise single sideband frequency . ( Previously, single sideband operation required a large, complex piece of equipment . ) The mechanical filter was the heart of Collins single sideband ( SSB ) technology, and made SSB practical for the first time.
44.
By filtering out unnecessary portions of the radio signal, the mechanical filter ( a kind of " bandpass filter " ) allows the use of a very stable, precise single sideband frequency . ( Previously, single sideband operation required a large, complex piece of equipment . ) The mechanical filter was the heart of Collins single sideband ( SSB ) technology, and made SSB practical for the first time.
45.
By filtering out unnecessary portions of the radio signal, the mechanical filter ( a kind of " bandpass filter " ) allows the use of a very stable, precise single sideband frequency . ( Previously, single sideband operation required a large, complex piece of equipment . ) The mechanical filter was the heart of Collins single sideband ( SSB ) technology, and made SSB practical for the first time.
