background image

Twice the Speed, 
Sensitivity, Resolution 
and More Control

Scope DSP

TMS320C6745 by Texas Instruments
32-bit floating point
2250 MFLOPS
370 MHz clock speed

Mini spectrum scope and audio scope

Mini dual spectrum scope and audio 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.

S p e c t r u m   S c o p e

Improved Spectrum Scope

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.

High Resolution Spectrum Waterfall Display

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.

Click Control

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. 

Span Width

Resolution *

1

Sweep Speed

Display Dynamic Range

Noise Floor Level

IC-7851

5kHz–1000kHz

1 pixel minimum *

2

29.3 frames/Sec *

3

100dB

–30dBμ

IC-7800

5kHz–1000kHz

20 pixels minimum *

4

 

4 frames/Sec *

3

80dB

–19dBμ

*

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 

Spectrum scope with waterfall
(wide screen setting)

• 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

• 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

Dual scope example (Vertically aligned)

Dual scope example (Horizontally aligned)

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 Function

Scope Comparison

Specifications for the audio scope

 Specifications for the oscilloscope

<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. 

3

Summary of Contents for IC-7851

Page 1: ...THE TRANSCEIVER...

Page 2: ...the design of the IC 7851 Icom s engineers focused on a new Local Oscillator LO that drastically reduces the phase noise As a result of this design the purity of the LO achieves a Reciprocal Mixing D...

Page 3: ...ssive 20dB improvement is seen with the IC 7851 s 10 kHz measure ment and more than 30dB improvement at a 1 kHz measurement in com parison to the IC 7800 Phase Noise Characteristics Comparisons Receiv...

Page 4: ...r 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 wel...

Page 5: ...851 has multiple AGC loops The AGC voltages detected in front of and behind the digital IF filter in the DSP unit The first AGC loop prevents saturation of the 1st IF amplifier The other AGC loop dete...

Page 6: ...eble The receive audio can be tailored with mode specific Bass Treble or audio passband settings Digital Twin PBT Passband Tuning Once the IF filters have been tweaked the op erator has additional con...

Page 7: ...synthesizer announces the operat ing frequency mode and S meter level Programmed scan memory scan select memory scan VSC scan and f scan Auto tuning step function Dial lock function Main dial tension...

Page 8: ...V 2 V 0 5 V 28 29 9MHz 50 54MHz 0 13 V 1 V 0 32 V SM 50 DESKTOP MICROPHONE IC PW1 IC PW1EURO HF 50MHz 1kW LINEAR AMPLIFIER SP 34 EXTERNAL SPEAKER Automatic antenna tuner and compact detach able contr...

Reviews: