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Icom is a pioneer in the amateur radio world. Starting with the first analog PLL circuit in the IC-200 to the ground-breaking 32-bit DSP technology used in the IC-756PRO, Icom’s developed some of the most innovative radio equipment ever made. Continuing with this tradition, Icom announces the ground-breaking IC-7800!
The IC-7800’s somewhat familiar looks will remind many HF operators of the IC-781. The IC-781 set benchmarks back in the 1980’s as that generation’s ultimate HF transceiver. Some of today’s operators still feel the IC-781 is the pinnacle in amateur radio design. They have not seen the IC-7800. It takes amateur radio to a whole new level of performance. The IC-7800 will be viewed as the pinnacle radio for years to come.
The IC-7800 is an artistic fusion of over 40 years analog RF circuit development expertise and cutting-edge digital technology. The result is TWO identical receivers with 110dB dynamic range, +40dBm 3rd order intercept point, and unmatched DSP technology in the HF bands something that has never been achieved in Ham radio!
Simply put, Icom has developed the ultimate Amateur HF transceiver. No one else comes close!
Icom’s considerable 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 re-engineered the whole analog circuit and matched it to the DSP units. This allowed us to explore new technical dimensions.
The IC-7800 uses durable mechanical relays for BPF switching instead of non-linear semi-conductors, like switching diodes which can cause distortion. The mechanical relay reduces secondary distortion at the primary stage of signal processing.
Contesters know how frustrating it is to experience a strong adjacent signal that's blocking the receiver from pulling out a weaker signal. Before the 1st amplifi er, the IC-7800's three Hi-Spec 1st IF filters* (roofing filter) adjacent signals. You can select the filter widths from 15kHz, 6kHz and 3kHz, depending on operating mode. (FM mode is fixed to 15kHz.)
* Icom calls the roofing filters “Hi-spec 1st IF filters”, because their
performance is much better than regular IF filters.
The pre-selector works between 1.5MHz and 30MHz and rejects distortion components derived from out of band interference such as multi-multi operation or strong broadcast stations. It automatically tracks the intended signal keeping the pre-selector’s bandwidth centered on the operating frequency. The center frequency of the pre-selector is manually adjustable from the DIGI-SEL tuning knob on the front panel.
Simple receiver system configuration is the best way to eliminate sources of the spurious signals and distortion from transceivers. The IC-7800 uses a double conversion system composed of a D-MOS FET 1st mixer and a newly developed image rejection mixer for the 2nd stage. The 1st mixer stage is driven with a signal from the high-drive Local Oscillator with excellent C/N. The image rejection mixer for the 2nd stage reduces signal distortion through IF processing and provides a high-fidelity signal to the DSP unit. This system provides wide dynamic range, reducing the distortion from strong signals and lower intermodulation.
The IC-7800 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 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.
The IC-7800 accommodates both the “on-the-fly” operator as well as the most avid “tweaker” operator by providing tunable AGC preset and manual AGC level controls. The AGC time constants can be set in the 3 presets (slow, medium and fast), adjustable from 0.1–6 sec. (0.3–8 sec. at AM) delay. Then the addition of the AGC VR control enables the user to “tweak” or fine tune the AGC reaction time.
The IC-7800 incorporates the “build your own” filter. This allows the operator to adjust filter shaping (sharp or soft), filter bandwidth, and center frequency characteristics, without missing the action. Multiple filter memories store the last used filter settings by using operation mode. This allows the operator to quickly switch filters for constant operating conditions, such as in a contest. Icom’s digital IF filters give you performance that is not possible with crystal or mechanical filters.
Once the IF filters have been “tweaked”, the operator has additional control with the digital twin Pass Band Tuning (PBT). The digital twin PBT allows flexibility of both the IF shift and narrowing of the digital IF passband by moving the IF passband. With the digital IF filters, PBT performance allows you to cut away all the interference and noise to hear the actual signal. In addition to the filter preset menu, the LCD indicates the twin PBT conditions across the top of the screen, so you can still use the lower portion of the TFT display for other radio operations.
In recent years, HF operators have marveled at how well DSP reduces interfering signals and noise. Signals such as heterodynes and AM Carriers can be eliminated with Automatic Notch filter technology. Making interference from RF sources such as beat signals and RTTY signals is a thing of the past. Additionally, the filter shape of the Manual Notch can be adjusted in three steps, with more than 70dB of attenuation!
The 32-bit DSP processing power of the IC-7800 produces real results by separating a signal component from the noise with the variable noise reduction. By suppressing the noise components, an outstanding signal-to-noise ratio is achieved, providing clean, clear audio in all modes without distortion of the target signal.
A newly designed, digital noise blanker significantly reduces pulse type noise. As part of the 32-bit DSP function, there are three adjustments: threshold level, blank time parameter, and attenuation level.
The IC-7800 was designed with the 6m aficionado in mind. Rather than sharing circuits used for HF, a separate preamplifier and mixer was designed especially for 6m. This greatly improves the receiver sensitivity by reducing intermodulation characteristics, enabling weak signal work without distortion or interference from strong signals in the band.
The IC-7800 incorporates four independent, 32- bit floating DSP units and 24-bit AD/DA converters. By having four independent DSP units, the radio will respond to operator changes in an instant, as each DSP unit has a dedicated function. While there is one for each receiver, this includes the AGC and Filter controls, there is a DSP unit for transmit as well as a DSP unit for the Spectrum Scope.
The IC-7800 incorporates two completely independent receivers, from the antenna inputs all the way though to the stereo headphone or individual external speaker outputs. All the performance of the first receiver is duplicated for a perfectly matched set of “Twins”. When connected to external stereo headphone, main and sub receiver audio can be mixed or separated to right and left.
With its introduction in the IC-781, having a spectrum scope in an HF radio changed the way HF operators “see” the band! Due to the DSP unit for the scope, the IC-7800’s spectrum scope provides excellent sensitivity, with 80dB of dynamic range. While the scope rivals many of today’s commercial test sets, there are 7 steps, ranging from ±2.5 to ±250kHz. This is up to 500kHz of spectrum! Also, there is a setting to allow for specific scope edges or center the span on the receiving frequency. In addition to these features, the scope has 3 levels of attenuator (10dB, 20dB, 30dB), 3 types of reference markers (main receiver, sub receiver, transmit), 3 levels of sweep speed (slow, mid, fast), peak hold and main/sub band one touch switch.
The IC-7800 uses the OCXO (Oven Control Crystal Oscillator) unit which is stable to within ±0.05ppm at 0˚C to 50˚C. This specification means that even on the 50MHz band, frequency error is less than 2.5Hz! In addition, a 10MHz reference frequency can be input and output for accurate tuning.
In the heat of a big contest or a DX-pedition, control placement is extremely important as every second counts. So Icom took a proven system, the IC-781, and used the basic front panel design for the IC-7800, incorporating improvements for all the new features and controls. Often used functions, including RF power and key speed have independent large knobs for easy access. The “XFC” button is placed efficiently for holding the button by the left hand, and moving the main dial with the right hand.
While Icom’s RF engineering team reviewed receiver designs for how the IC-7800 hears a signal, close attention was also paid to how the operator sees a signal. Details such as response time, color, resolution, and visibility were extremely important. Thus, an active matrix 7-inch (800×480 pixel) TFT color display was selected for the IC-7800. This large display shows main, sub-band frequencies, including various settings, and operating conditions, as well as the spectrum scope, S-meter, and RTTY/PSK31 decoded messages. The “virtual” S-meter shows smooth and accurate analog-looking needle swings whose response is selectable from 3-steps (fast/mid/slow). In addition to the “virtual” meters, the IC-7800 has digital multi-function bar graphic meters to show various conditions, including transmitter PA temperature and voltage. If a larger display is desired, the IC-7800 has a VGA connector for an external monitor and an S-meter connector for an external analog S-meter.
Another amateur radio first is the capability of receiving and transmitting RTTY and PSK31 without the aid of a computer. While decoded RTTY and PSK31 is shown on the 7-inch display, simply connect a USB keyboard to the IC-7800 to send as well. To reduce errors in receiving RTTY, the IC-7800 has a digital twin peak filter to reduce interference from other signals in the band. In the PSK mode, the AFC function tracks the receiving signal for accurate tuning and the NET function allows you to send at the shifted frequency. In addition, a total 8 channels of RTTY and PSK31 transmit memory stores up to 70 characters of often used messages for each channel.
The newly designed push-pull power amplifiers using power MOS-FETs work on 48V DC. They provide a powerful 200W output power at full duty cycle and low transmit intermodulation. An effective cooling system maintains internal temperatures within a safe range and prevents thermal runaway.
One of the four 32-bit DSP units is used for adjusting the transmit audio. Digitally tweak your transmit audio with the separate bass and treble controls for incredible sounding audio. This built-in audio equalizer has a total of 121 combinations for each phone mode, so you can master the warm, full audio you want. In addition to the equalizer, a new parametric transmit bandwidth for the SSB mode allows the operator to set both the high- and low-pass filter limits. (100, 200, 300, 500 for the high-pass and 2.5, 2.7, 2.8 and 2.9 kHz for the low-pass). Then store the filter settings into the three bandwidth memories. The operator may now go from DX to rag chew audio with the push of a button.
The IC-7800 utilizes the 32-bit DSP for the RF speech compressor providing the maximum punch without the fuzzy sound. It’s great for breaking through the noise and hash to complete the QSO.
Making big scores means keeping your team fresh on those long DX-peditions or Multi Op contests. Swapping out operators usually involves time-wasting radio tweaks, because each operator has their own favorite settings to best match their operating style. This all changes with the CF memory card! Prior to a contest, operators may record their preferred IC-7800 settings such as filter, Digital Voice Recorder (DVR) memories, antenna settings, etc. When it’s their turn to operate, simply insert their CF card into the IC-7800. In a flash, the ‘7800 is now “their rig”, and there’s nearly zero down time!
The IC-7800’s Digital Voice Recorder (DVR) is a very convenient function for contests, DX-peditions, and even normal operation. Record your callsign, CQ, or contest number in up to four memory locations. A total of 90 seconds is available for the four memories, with each memory channel being soft partitioned to allow custom recording sizes. The front panel control of the DVR allows you to record incoming signals up to 200 seconds for 20 channels (Max. 30 sec. per channel). The playback automatically mutes the receiver for clear playback of the previous 15 seconds of recorded audio. It’s the perfect feature for those contest operators wanting to improve their UBN reports.
For the AFSK operators, the IC-7800 automatically adjusts its digital IF filters for optimum settings. When the digital IF filters are adjusted to 500Hz or less in SSB or SSB-D, the sharp CW bandpass filter (BPF) is selected and the 1/4 tuning step is selected.
For the ultimate in antenna control, the IC-7800 has 4 antenna connectors with a programmable automatic antenna selector. Each antenna connector can be customized to the antenna usage type, such as a beam for TX and a beverage antenna for RX, as well as to specific antenna/band configurations.
All of the following CW capabilities are included in the IC-7800: