Model BWD 539D is a portable dual trace oscilloscope
providing a measurement capability that is unique in an
instrument of its class. The identical vertical amplifiers
have a -3db response >25MHz and are useful for signal
monitoring to beyond 30MHz. Stable triggering extending to >
30MHz makes the BWD 539D suitable for use with 27MHz C.B.
and radio control gear. The two vertical amplifiers may be
cascaded for a single channel display over a bandwidth of
12Hz to 100kHz at a sensitivity of 0.5mV/cm.
The time base and trigger facilities complement the vertical
amplifier performance with a sweep range from lOOnSec/cm to
2.5sec/cm whilst waveforms can be triggered from 2Hz to over
20MHz and presented with complete stability. Video displays
are well catered for with an active sync separator supplying
frame or line pulses for stable lock even if the signal is
almost lost in noise. Additional versatility is provided by
the sync separator as it also operates as an AM demodulator
enabling double or single sideband displays to be locked to
the modulation envelope.
Identical X-Y operation is also incorporated in the 539D and
is phase corrected from DC to over 200kHz enabling accurate
phase measurements to be made over this range.
Applications requiring accurate phase measurements to power
line operated equipment can be readily made on a BWD 539D as
it incorporates a zero crossover reference waveform in the
calibrator output. When this waveform is used to provide
external trigger for the time base, the start of the trace
will be within 2° of the power line 0° or 180° cross over
points. Thus firing angles of thyristors or triacs can be
measured to within 2 or 3°.
Application notes relating to all the oscilloscopes
facilities are contained in Section 6 and 7.
To ensure a long and trouble free life certain precautions
should always be observed with electronic instruments. If it
is left standing for long periods or is used in a dusty
atmosphere keep the instrument covered with a plastic dust
cove'r or in a cupboard.
Although this instrument has been designed for reliable long
term use and has been subject to environmental tests and
heat soaked, it is always advisable to store it away from
heat or out of direct intense sunlight to minimise
temperature cycling of components and possible premature
drying out of electrolytic capacitors. Internal temperature
rise of the 539D is low but care should still be taken to
ensure that the cabinet has adequate ventilation.