Video signals are recorded according to the number of tracks corresponding
to the broadcasting system for each basic unit. When control signals are
recorded on a magnetic tape in the longitudinal direction, the duty ratio
of the control signals for every N tracks recorded for each basic unit has
a value different from that of the duty ratio of other control signals. At
the time when the magnetic tape 1 is reproduced CTL signals are obtained
by forming waveforms of the reproduced amplified outputs by means of a
waveform formation unit 6. A CTL signal duty ratio determination unit 9
detects the border of a frame in accordance with the duty ratio. A
broadcasting a system determination unit 10 determines the broadcasting
system based on the counting result of the CTL signals during one frame
that has been counted by the CTL signal counting unit 9. Thereby, it is
made possible to record and to reproduce programs of a differing
broadcasting system by using an information recorder/reproducer of which
the number of revolutions of the rotating cylinder and the transfer speed
of the magnetic tape are the same.
