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IC-7800

THE ULTIMATE PRODUCT OF 40 YEARS ACCUMULATED RF EXPERTISE
Icom has been developing radio communication equipment for over fortyyears. Our history has been technical challenge and excellence from thefirst analog PLL circuit in the IC-200, to the ground-breaking 32-bit floating point DSP of the IC-756PRO. Icom has always given shape to ideas with this technical accumulation. Recent Ham radio stations increasingly use high power and high gain antennas that raise the field strength of unintended signals, and thus require a wider receiver dynamic range. Icom has developed the new flagship model IC-7800 which is a fusion of forty years analog RF circuit development expertise, withcutting edge digital technology.

The result is 110dB dynamic range, +40dB 3rd order intercept point in HF bands and other phenomenal performance features. The receivers combine various current and new technology, to obtain the +40dBm IP3, a specification never before achieved in Ham radio. Quite simply put, the IC-7800 is the ultimate Ham radio. Nothing else comes close! 

Astonishing +40dBm 3rd order intercept point in HF bands
Two completely independent receiver circuits allowing reception of two different bands in different modes simultaneously
Four 32-bit floating point DSP units (Two for the receivers, one for the transmitter, one for the spectrum scope)
Full power, full duty cycle 200W output
0.05ppm high stability OCXO unit installed as standard

+40dBm IP3 (3rd order Intercept Point)

Dynamic range characteristics
Dynamic range characteristics
Icom's 40 years of analog RF circuit experience combined with cutting edge digital technology results in an astonishing 110dB receiver dynamic range and a +40dBm IP3 in the HF bands. A first in Ham radio! To achieve this superior receiver performance, Icom's engineering team completely reviewed the whole analog circuit and matched it to the DSP units. This allowed us to explore new technical dimensions such as a double conversion super-heterodyne system, mechanical relay BPF switching and two roofing filters.

Mechanical relay BPF (Band Pass filter) switching and two roofing filters
The IC-7800 uses highly reliable and durable mechanical relays for BPF switching instead of non-linear semi-conductors which cause distortion. The mechanical relay prevents 2nd order distortion at the primary stage of signal processing. The IC-7800 has two roofing filters before the 1st IF amplifier stage. One is 15kHz fileter for FM mode and the other is 6kHz filter for SSB, CW, AM and data modes. The IC-7800 switches between these two roofing filters depending on operating mode. Typically, transceivers use only one broad 15kHz roofing filter for all modes. This is not an optimal design for SSB, CW, or AM modes. The two roofing filters dramatically improve the blocking characteristics from strong adjacent signals.

BPF Unit
BPF Unit
Two roofing filters
Two roofing filters

Automatic tracking pre-selector
The pre-selector works from 1.5MHz to 30MHz. The preselector automatically tracks the intended signal, keeping the pre-selectorfs bandwidth centered on the operating frequency at several kHz steps (minimum). The preselector rejects unwanted out of band interference from multi-multi operation or strong broadcast stations, as your first line of defense against interfering signals. The center frequency of the pre-selector is adjustable from the DIGI-SEL tuning knob on the front panel.

Automatic preselector
Automatic preselector
Automatic Preselector Characteristics in 14MHz band
Automatic Preselector Characteristics in 14MHz band

Double conversion super-heterodyne system
While mixers often become a cause of signal distortion and spurious emissions, the IC-7800 utilizes a double conversion super-heterodyne system using a newly developed image rejection mixer. A high performance D-MOS FET array for the 1st mixer stage is infused with a signal from the high-level C/N, high-drive Local Oscillator from the PLL unit. This new mixer reduces signal distortion through IF processing and provides a high-fidelity signal to the DSP unit.

AGC loop management using the DSP unit
The IC-7800 has two types of AGC loops. One of the AGC loops detects the AGC voltage at the BPF input in the DSP unit and feeds back to the 1st IF amplifier. This AGC loop prevents the saturation of the 1st IF amplifier from strong signals out of the BPF bandwidth, and improves the dynamic range against adjacent signals. The other AGC loop detects the AGC voltage at the digital IF filter output which has only passed the intended signal and draws the full potential from the digital IF filter. Combining the digital IF filter, manual notch, and the 1st IF stage, these are all controlled by the DSP unit. 110dB of ultra wide dynamic range in the receiver means the IF amplifier is distortion free from strong signals.


AGC Volume knob for fine tuning
AGC setting screen
AGC setting screen
In addition to the preset AGC time constants (slow, medium and fast), the manual AGC volume provides flexible detailed AGC tuning.

Two completely independent receiver circuits
The ultimate dual receiver performance is at your control; the receivers are completely independent all the way from the 4 antenna jacks, through the pre-selectors, DSP, signal detectors, front panel control, and right into the stereo headphone! The dual receiver allows you to receive two different bands simultaneously in different modes, with each receiver not causing any adverse affect to the other one. This true dual receiver takes your band hopping and contesting experience to the next level!


Digital IF filter
Filter preset screen
Filter preset screen
The digital IF filter has superior filtering performance and a distinguished shaping factor that demonstrates the power of 32-bit floating point DSP. The digital filter is completely free from deterioration due to deviations in band characteristics, temperature change, or mechanical vibration, all of which have likely been seen with analog filters. The digital IF filter also provides excellent ripple characteristics and clean cut that have never been available with analog filters. The filter shape is selectable from soft and sharp, depending on the purpose, operating band, band conditions, etc. It is also possible to set CW and SSB filter characteristics independently, and also select the filter shape while actually receiving a signal.

Manual notch filter with adjustable notch filter characteristics
Manual Notch (Wide/Middle/Narrow)
Manual Notch (Wide/Middle/Narrow)
The IC-7800's manual notch filter shape can be set in 3- steps for the various receiving conditions. The manual notch filter has extremely sharp characteristics for processing in the DSP and provides tremendous performance for attenuation levels of more than 70dB in all shapes. The DSP-based manual notch provides stable performance and completely shuts off undesired beat signals without affecting AGC gain. In addition, an automatic notch filter tracks and wipes off the beat signal and RTTY interference.

Four 32-bit floating point DSP units and 24-bit AD/DA converters
32-bit Floating point DSP chip
32-bit Floating point DSP chip
The IC-7800 uses four pairs of 32-bit floating point DSP units and 24-bit AD/DA converters. One for the transmitter, one for each receiver, and the final one for the spectrum scope. The DSP units deliver the phenomenal performance of the digital signal processing. A powerful combination born of Icomfs analog RF technology and experience.

200W output power at full duty cycle
PA Unit and large heat sink
PA Unit and large heat sink
The newly designed push-pull power MOS-FET amplifiers work with 48V DC and provide a powerful 200W of output power at full duty cycle with low IMD in all bands. The digital PSN modulator using a dedicated DSP unit consistently reproduces an outstanding signal-to-noise ratio, providing clean and clear transmission.

Ultra high stability OCXO unit
Your IC-7800 will be the reference point on the band with a standard stability of &plusml;0.05ppm! Even on the 6m band, that is less than 3Hz error from the Oven Controlled Crystal Oscillator! Also, a 10MHz reference frequency can be the input/output for external equipment.

OCXO Unit
OCXO Unit
Reference input/output connector
Reference input/output connector

RTTY/PSK31 operation without PC connection
RTTY Decode screen
RTTY Decode screen
The IC-7800 has a modulator and demodulator for the 2 major HF ham digital modes. Encode and decode of PSK31 and Baudot RTTY signals are possible by simply connecting a USB keyboard to the IC-7800. The twin peak audio filter improves RTTY reception. In addition, transmitted and received messages can be stored to the CF memory card and transferred to your PC.

 

 



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