The IC-7851 is the company's new flagship amateur radio and incorporates a new local oscillator (LO) design, an optimized roofing filter, enhanced spectrum scope to name but a few of its many functions. Raising the bar for HF operation, the IC-7851 is ideal for contesters, DXers and the serious amateur radio operator. Icom's new radio features a new LO design which utilizes a Direct Digital Synthesizer (DDS) along with a Phase Locked Oscillator.
HF/50MHz Transceiver - The Pinnacle of HF Perfection
The IC-7851 also features enhanced spectrum scope functionality. A dedicated Digital Signal Processing (DSP) unit is used for the Fast Fourier Transform (FFT) spectrum to provide faster sweep speeds and finer accuracy. Audio scope and dual scope functions, combined with a high-resolution spectrum waterfall display, provide twice the speed, sensitivity and control to give operators a performance edge.
Other radio highlights include USB-enabled click and enhanced PC control. When combined with the optional Icom RS-BA1 software, the IC-7851's internal server promotes remote base station operation. The radio can connect directly to a router and does not require a second computer for audio or rig control. The IC-7851 also continues various benchmarks established by Icom's celebrated IC-7800 such as +40dBm iP3 (3rd order intercept point), 200W output power at full duty cycle and more.
1.2kHz "Optimum" roofing filter
The IC-7851 utilizes a newly developed 1.2kHz roofing filter, greatly improving the in-band adjacent signal performance. This enhancement enables the up-conversion design of the IC-7851 to have excellent filter performance while providing a dynamic range that outperforms the competition in the 10kHz or less separation tests.
New local oscillator design
Breaking tradition, Icom employs a Direct Digital Synthesizer (DDS) along with a Phase Locked Oscillator for the IC-7851’s Local Oscillator (LO). The LO's C/N ratio excels beyond our competitors, and the noise components generated in both receive and transmit signals are reduced virtually below detection.
LO C/N Characteristics Comparisons 1st LO @ 14.1MHz
Improved phase noise
With the latest design of the LO, the IC-7851 will become the new benchmark for Phase Noise with –150dBc/Hz at 10kHz offset and –140dBc/Hz even at 1kHz offset. (Previous mark of Phase Noise excellence was –138dBc/Hz at 10kHz offset and –110dBc/Hz at 1kHz offset.)
Brand A premium model
Improved spectrum scope
By using the dedicated DSP for the Fast Fourier Transform (FFT) spectrum scope, the IC-7851 provides faster sweep speeds and better accuracy than other brand models, even the IC-7800.
Span Width 5kHz–1000kHz
Resolution *1 1 dot *3
Sweep Speed 29.3 samples/Sec *4
Input Dynamic Range 116dB *5
Max. Sensitivity *2 –39dBµ *5
*1 Number of dots shown at 60dB level, when receiving a signal
*2 Recognized level at the Spectrum Waterfall
*3 SPAN=More than 20kHz, SPEED=Slow
*4 SPAN=Less than 20kHz, SPEED=Fast
*5 SPAN=5kHz, SPEED=Slow
Dual scope function
Another scope enhancement in the IC-7851 is the ability to simultaneously “see” activity in both bands. This is useful when searching for multipliers on the Sub band while maintaining your operating frequency on the Main band.
Photo dual scope example (vertically aligned)
Enhanced mouse operation for the spectrum scope
Connect a mouse to the USB port to change the operating frequency, tune the frequency, switch Fixed and Center mode, adjust the sweep speed and more. Also, simply click on a signal on the scope and the frequency is automatically selected as your operating frequency.
Photo depicts specturm waterfall.
Other outstanding features:
-Simplified RS-BA1 Remote Control
-Supports PSK63 as well as PSK31
-SD card slot for voice and data storage
-USB, Ethernet and S/P DIF Interfaces
-Enhanced Digital Voice Recorder
-Comfortable solid feel main dial
-Firmware updates can be made from an SD card or USB flash drive
The number of memory channels
Operating temperature limit
Spurious emission intensity
Carrier suppression ratio
Unnecessary sideband suppression ratio
TX variable range
Receiver sensitivity (TYP)
AM (BW = 6kHz) (when 10dB S / N)
FM (BW = 15kHz) (when 12dB SINAD)
Spurious interference ratio
Low-frequency load impedance
RIT variable range