Icom IC-7851 Quick Start Manual page 4

S p e c t r u m S c o p e
Twice the Speed,
Sensitivity, Resolution
and More Control
Improved Spectrum Scope
Following the design linage of the IC-7800, the IC-7851 uses a dedicated
DSP unit for the Fast Fourier Transform (FFT) spectrum. The 2250
MFLOPS DSP processor enables a new dual scope function and signifi-
cantly faster sweep speeds and better accuracy than in the IC-7800.
Scope Comparison
Span Width
Resolution * 1
Sweep Speed
Display Dynamic Range
Noise Floor Level
1
* Number of dots shown at the 60 dB level, when receiving a signal.
* 2
SPAN = More than 20 kHz, SPEED = Slow
* 3
SPAN = Less than 20 kHz, SPEED = Fast
4
* SPAN = 500 kHz, SPEED = Slow
Audio Scope Function
The audio scope simultaneously shows an oscilloscope and FFT for receive
and transmit audio. Adjust your transmit audio by watching your compressor
level, equalization and mic gain settings to give you the audio you want for
SSB. The oscilloscope shows the CW waveform. On receive, you can see the
power of your filtering by watching filtering adjustments take out interfering
signals including filter width and notch filter placement. The processing power
in the IC-7851 allows for dual mini band scopes as well as the audio scope.
Specifications for the audio scope
• Attenuator: 0 dB, –10 dB, –20 dB and –30 dB
• FFT scope with waterfall and FFT scope without waterfall
• Waveform color and drawing (outline or fill) settings
for the FFT scope
Mini spectrum scope and audio scope
3
Scope DSP
TMS320C6745 by Texas Instruments
32-bit floating point
2250 MFLOPS
370 MHz clock speed
IC-7851 IC-7800
5kHz–1000kHz 5kHz–1000kHz
2
1 pixel minimum * 20 pixels minimum *
29.3 frames/Sec * 3 4 frames/Sec *
100dB 80dB
–30dBμ –19dBμ
Specifications for the oscilloscope
• Level: 0dB, –10 dB, –20 dB and –30 dB
• Sample rate: 1ms/Div, 3ms/Div, 10ms/Div, 30ms/Div,
100ms/Div and 300ms/Div, 5 Div width
• Waveform color setting
Mini dual spectrum scope and audio scope
Dual Scope Function
While you can watch both receivers on the scope of the IC-7800, within the
limits of the scope bandwidth, the IC-7851 introduces the new dual scope –
the ability of watching both receivers in separate spectrum scopes. The
dual scope function is vital for watching for multipliers or band openings in
contests, or working all bands/modes on a DXpedition.
Dual scope example (Vertically aligned)
4
High Resolution Spectrum Waterfall Display
3
The waterfall display captures signal strengths over time. This allows
you to see signals that may not be apparent on a normal scope. Addi-
tionally, the combination of the scope attenuator and the wide screen
mode gives you a better view of
weaker signals as band conditions
c h a n g e . F o r t h e u l t i m a t e s c o p e
enhancement, the IC-7851 has a
digital video interface (DVI-I) for a
larger display.
Click Control
By connecting a human interface device (such as a USB mouse, trackball or
touchpad) to the USB port on the rear panel, you gain control over the spec-
trum display pointer for "Click-and-Listen" receiver control. Fix/Center mode,
sweep speed and other settings are controllable.
<For example>
• Left click to change operating frequency
• Click a button (either left or right) and move
right or left side on the screen to increase or
decrease the operating frequency (similar to
rotating the main dial)
• Right click to temporarily change the receive
frequency. Release the mouse button to return.
Dual scope example (Horizontally aligned)
Spectrum scope with waterfall
(wide screen setting)