HF/50MHz Transceiver – The Pinnacle of HF Perfection
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
Brand A premium model
Brand B premium model
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.)
Phase Noise Characteristics 1st LO @ 14.1MHz
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.
|Resolution *1||1 dot *3|
|Sweep Speed||29.3 samples/Sec *4|
|Input Dynamic Range||116dB *5|
|Max. Sensitivity *2||–39dB? *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 to the right depicts 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 to the right 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