Description, Data Sheet FCKL 1528 Page -3
Modes of operation
The FCKL 1528 covers the following modes:
w
Manual operation with manual
frequency tuning and reading the
measurement from the meter.
w
Semi-automatic operation using an xy-
recorder for the reading.
w
PC-controlled operation via IEEE-bus
with Schwarzbeck Software.
Manual operation
As no other this mode of operation gives
direct access to the receiver without any
collision with PC or software. Especially in
the measuring field outside of a shielding
room, broadcast signals can be identified
using the demodulator/loudspeaker. CW-
signals can be monitored with 0 kHz and
1 kHz beat frequency.
Reading can be seen clearly on the meter
which gives perfect reading from narrow
band signals down to single click.
§
The meter uses the classic 0 dB centre
of meter scaling for safe measurement
without interpretation.
§
The linear scale gives true linear voltage
reading avoiding problems with slow
pulses.
§
For any interference signal from
continuous distortion to single click 0 dB
centre of instrument is free of overload
problems. For overview a 50 dB scaling
can be used.
Semi-automatic operation
Spectrums can be recorded when the
receiver is used in the scan mode
together with an xy-recorder.
The time consumption is reduced
substantially, because VARISCAN adjusts
scan speed to the signals ahead.
So spectrum can be scanned directly in
CISPR-Quasipeak to avoid switching
CISPR/Peak. The xy-recorder can be
used in manual tuning mode as well. The
xy-recorder then follows the manual
frequency tuning on the encoder. Doing
so, it is very easy to stop on critical
frequencies to find the maximum signal
strength, which will be kept by the xy-
recorder.
PC-controlled mode
Using a standard PC, a IEEE-card and the
Schwarzbeck software Messbase together
with the FCKL 1528 gives PC-controlled
measurement. Modern PCs offer high
speed and high capacity hard disks which
improve considerably storage and
documentation of measurement.
Primary goal of development was safe
measurement of the complete range of
interference signals keeping the high
standard of manual measurement. This
means that there must be no trade off
considering even slow pulses.
The completely new approach using the
fourth demodulator included in VARISCAN
gives fast Quasipeak, CAV and CRMS
measurement without using the Peak
detector. VARISCAN analyses the signal
ahead before it is really measured.
Practical spectrum often shows amplitude
jitter which could be subject to
misinterpretations using the Peak detector
to decide which signal has to be re-
measured in Quasi-Peak or not.
The second step towards safe
measurement is controlling the receiver by
the limits given in the standards.
Basically autorange can catch any signal,
but there are restrictions when slow
pulses occur.
The way out of the problem is to guide the
receiver along the limits in such a way,
that it is centred in the middle between
noise and overload. Even antenna factors
are included in this strategy.