Getting Started |
Limitations of the Signal Hound
5
packets, will be displayed accurately in this mode. Other modes will work, but modulation details may be
masked out by the image rejection algorithm, and pulses and short packets may be missed entirely.
Image rejection is not available in this mode, therefore the image frequency, 21.4 MHz above the signal,
will not be suppressed, and spurious responses may be present.
2.2.3
Zero Span Mode
For modulated signals not exceeding 250 kHz bandwidth, time-domain amplitude, frequency, and phase
information, as well as several modulation measurements, are available in Zero Span mode. See the
Spike
TM
manual for additional information. Image rejection is not available in this mode, therefore the
image frequency, 21.4 MHz above the signal, will not be suppressed, and spurious responses may be
present.
2.2.4
Attenuator, Preamplifier, Intermediate Frequency and
Gain, and ADC Clock Settings
The Signal Hound switches between two intermediate frequencies, four attenuator settings, two
preamplifier settings, two ADC clock frequencies, and three IF gain settings when measuring signals and
performing image suppression. Unless you explicitly disable the automatic settings, the best settings for
your reference level, center frequency, and span will be automatically selected. Simply select a reference
level that is a few dB above the input signal level.
2.3
LIMITATIONS OF THE SIGNAL HOUND
2.3.1
RBW Limitations
The maximum resolution bandwidth (RBW) of the SA44B is 250kHz, and the minimum is 0.1Hz. There
are additional restrictions on RBW depending on span and start frequency.
For spans between 201kHz and 99MHz with a start frequency above 16MHz, the RBW can be set
between 30Hz and 250kHz.
For spans larger than 99MHz or sweeps that start below 16MHz, the RBW can be set between 6.5 kHz
and 250kHz.
All RBWs are available for spans 200kHz or less.
Outside of these limitations, a 5MHz RBW is available through the use of an internal power detector. The
power detector can only be enabled with a start frequency and span above 200MHz.
To measure wider bandwidths, the channel power utility must be used. See the Spike
TM
software manual
for additional information on channel power.