IC-7800_broch.pdf

From 40 years of RF design expertise comes the Masterpiece Ham Radio Transceiver 90 Phase shifter 90 Phase shifter 1st mixer 1st LO 6kHz BW (Except FM mode) 3kHz BW (Except FM mode) 15kHz BW AGC Loop line DSP Circuit 2nd mixer (Image rejection mixer) A/D D/A AGC DET AMPAMPBPF IFIF AMPAMP IF AMP IFIF AMPAMP IF AMP IFIF AMPAMP IF AMP IFIF AMPAMP IF AMP LPF BPF BPF BPF AGC DET BPF CPU Pre- selector AMP Icom is a pioneer in the amateur radio world. Starting with the first analog PLLcircuit in the IC-200 to the ground-breaking 32- bit DSP technology used in the IC-756PRO, Icoms developed some of the most innovative radio equipment ever made. Continuing with this tradition, Icom announces the ground- breaking IC-7800! The IC-7800s somewhat familiar looks will remind many HF operators of the IC-781. The IC-781 set benchmarks back in the 1980s as that generations ultimate HF transceiver. Some of todays 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! +40dBm IP3 (3rd order Intercept Point) Icoms considerable analog RF circuit experi- ence combined with cutting-edge digital technol- ogy results in an astonishing 110dB receiver dynamic range and a +40dBm IP3 in the HF bands. A fi rst in Ham radio! To achieve this su- perior receiver performance, Icoms engineering team completely re-engineered the whole analog circuit and matched it to the DSP units. This al- lowed us to explore new technical dimensions. Internal distortion reduction The IC-7800 uses durable mechanical relays for BPF switching instead of non-linear semi-con- ductors, like switching diodes which can cause distortion. The mechanical relay reduces sec- ondary distortion at the primary stage of signal processing. Improved blocking Contesters know how frustrating it is to experi- ence a strong adjacent signal thats blocking the receiver from pulling out a weaker signal. Before the 1st amplifier, the IC-7800s three roofing fil- ters block strong adja- cent signals. You can select the fi lter widths from 15kHz, 6kHz and 3kHz, depending on operating mode. (FM mode is fi xed to 15kHz.) Icoms DIGI-SEL The pre-selector works between 1.5MHz and 30MHz and rejects distortion components de- rived from out of band interference such as multi- multi operation or strong broadcast stations. It automatically tracks the intended signal keeping the pre-selectors bandwidth centered on the op- erating frequency. The center frequency of the pre-selector is manually adjustable from the DIGI-SEL tuning knob on the front panel. Less internal phase noise 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 re- jection mixer for the 2nd stage reduces signal dis- tortion through IF processing and provides a high-fidelity signal to the DSP unit. This system provides wide dynamic range, reducing the distor- tion from strong signals and lower intermodulation. Multiple AGC loops The IC-7800 has multiple AGC loops. The AGC voltages detected in front of and behind the digi- tal 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 fi lter output which has only passed the intended signal and draws the full potential from the digital IF fi lter. Combining the digital IF fi lter, 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 am- plifi er is distortion free from strong signals. Full AGC controls The IC-7800 accommodates both the “on-the-fl y” operator as well as the most avid “tweaker” op- erator by providing tunable AGC preset and manual AGC level controls. The AGC time con- stants can be set in the 3 presets (slow, medium and fast), adjustable from 0.16 sec. (0.38 sec. at AM)delay. Then the addition of the AGC VR control enables the user to “tweak” or fi ne tune the AGC reaction time. Digital IF fi lter The IC-7800 incorporates the “build your own” fi l- ter. This allows the operator to adjust fi lter shap- ing (sharp or soft), filter bandwidth, and center frequency characteristics, without missing the ac- tion. Multiple filter memories store the last used filter settings by using operation mode. This al- lows the operator to quickly switch fi lters for con- stant operating conditions, such as in a contest. Icoms digital IF fi lters give you performance that is not possible with crystal or mechanical fi lters. Digital twin PBT (Passband Tuning) Once the IF fi lters have been “tweaked”, the op- erator has additional control with the digital twin PassBand Tuning (PBT). The digital twin PBT al- lows fl exibility of both the IF shift and narrowing of the digital IF passband by moving the IF pass- band. With the digital IF fi lters, PBT performance allows you to cut away all the interference and noise to hear the actual signal. In addition to the fi lter preset menu, the LCD indi- cates 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. BPF unit DIGI-SEL unit AGC setting screen REF0.0dBm30.0dBmMKR 14.16MHzDL 10dB/ 0dB 8.73dBm *A_Write Norm B_Blank Norm START0HzSTOP 30.00MHz RBW300kHzVBW300kHzSWP200msATT10dB DIGI-SEL Characteristics in the 14MHz band MARKER 14.16MHz 90 Phase shifter 90 Phase shifter AGC Loop line DSP unit 2nd mixer Image rejection mixer A/D D/A AGC DET AMPAMP IF AMP BPF AGC DET IF AMP IF AMP IF AMP Filter preset screen. Dynamic range characteristics (in 14MHz band) Audio output level Input level at the antenna connector dBm IP3 (3rd order Intercept Point) 3dB dB 50 40 30 20 10 0 Sensitivity 3rd order Intermodulation Noise floor level Dynamic range 110dB +40dBm Three roofi ng fi lters Digital manual notch fi lter In recent years, HF operators have marveled at how well DSP reduces interfering signals and noise. Signals such as heterodynes and AM Carri- ers can be eliminated with Automatic Notch fi lter 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! Variable level noise reduction The 32-bit DSP processing power of the IC-7800 produces real results by separating a signal component from the noise with the vari- able 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. Adjustable noise blanker A newly designed, digital noise blanker signifi- cantly reduces pulse type noise. As part of the 32-bit DSP function, there are three adjustments: threshold level, blank time parameter, and atten- uation level. 50MHz band preamplifi er and mixer The IC-7800 was designed with the 6m afi- cionado in mind. Rather than sharing circuits used for HF, a separate preamplifier and mixer was designed especially for 6m. This greatly im- proves the receiver sensitivity by reducing inter- modulation characteristics, enabling weak signal work without distortion or interference from strong signals in the band. Quad processing The IC-7800 incorporates four independent, 32- bit fl oating DSP units and 24-bit AD/DA convert- ers. By having four independent DSP units, the radio will respond to operator changes in an in- stant, as each DSP unit has a dedicated function. While there is one for each receiver, this in- cludes the AGC and Filter controls, there is a DSP unit for transmit as well as a DSP unit for the Spectrum Scope. Two completely independent receiver circuits The IC-7800 incorporates two completely inde- pendent receivers, from the antenna inputs all 100 8006004002000200400600800 90 80 70 60 50 40 30 20 10 0 10dB Hz Wide Middle Narrow Manual notch fi lter characteristics DSP Unit the way though to the stereo headphone or indi- vidual external speaker outputs. All the perfor- mance of the first receiver is duplicated for a perfectly matched set of “Twins”. When con- nected to external stereo headphone, main and sub receiver audio can be mixed or separated to right and left. Real time spectrum scope With its introduction in the IC-781, having a spec- trum scope in an HF radio changed the way HF operators “see” the band! Due to the DSP unit for the scope, the IC-7800s spectrum scope pro- vides excellent sensitivity, with 80dB of dynamic range. While the scope rivals many of todays 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 specifi c scope edges or center the span on the receiving fre- quency. In addition to these features, the scope has 3 levels of attenuator (10dB, 20dB, 30dB), 3 types of reference markers (main receiver, sub re- ceiver, transmit), 3 levels of sweep speed (slow, mid, fast),peak hold and main/sub band one touch switch. at 0C to 50C. This specifi cation 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. Central Control In the heat of a big contest or a DX-pedition, con- trol placement is extremely important as every second counts. So Icom took a proven system, the IC-781, and used the basic front panel de- sign 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 effi ciently for holding the button by the left hand, and moving the main dial with the right hand. OCXO Unit The above photo shows actual size. Ultra high stability OCXO unit The IC-7800 uses the OCXO (Oven Control Crystal Oscillator)unit which is stable to within 0.05ppm Example of spectrum scope centered on the receiving frequency. Example of fi xed spectrum scope range. Mini scope screen. 7-inch wide color TFT LCD While Icoms RF engineering team reviewed re- ceiver 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 (800480 pixel)TFT color display was selected for the IC-7800. This large display shows main, sub-band frequen- cies, including various settings, and operating con- ditions, as well as the spectrum scope, S-meter, and RTTY/PSK31 decoded messages. The “virtual” S-meter shows smooth and accurate analog-look- ing needle swings whose response is selectable from 3-steps (fast/mid/slow). In addition to the “vir- tual” meters, the IC-7800 has digital multi-function bar graphic meters to show various conditions, in- cluding transmitter PAtemperature 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. RTTY/PSK31 operation without PC connection Another amateur radio fi rst is the capability of re- ceiving and transmitting RTTY and PSK31 with- out the aid of a computer. While decoded RTTY and PSK31 is shown on the 7-inch display, sim- ply 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 fi lter 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 charac- ters of often used messages for each channel. 200W output power at full duty cycle The newly designed push-pull power amplifi ers 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 tem- peratures within a safe range and prevents ther- mal runaway. Microphone equalizer One of the four 32-Bit DSP units is used for ad- justing 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 fi lter 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 fi lter settings into the three bandwidth memories. The operator may now go from DX to rag chew audio with the push of a button. RF speech compressor The IC-7800 utilizes the 32-bit DSP for the RF speech compressor providing the maximum punch without the fuzzy sound. Its great for breaking through the noise and hash to complete the QSO. CF memory card Making big scores means keeping your team fresh on those long DX-peditions or Multi Op contests. Swapping out operators usually in- volves 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, opera- tors may record their preferred IC-7800 settings such as fi lter, Digital Voice Recorder (DVR)mem- ories, antenna settings, etc. When its their turn to operate, simply insert their CF card into the IC-7800. In a fl ash, the 7800 is now “their rig”, and theres nearly zero down time! Digital voice recorder The IC-7800s Digital Voice Recorder (DVR)is a very convenient function for contests, DX-pedi- tions, and even normal operation. Record your callsign, CQ, or contest number in up to four memory locations. A total of 90 seconds is avail- able 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 play- back automatically mu