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1、HF/50MHz TRANSCEIVER Perfection In its purest form. 1 To Amateurs That Share An Appreciation of Design and Value 2 HF/50MHz TRANSCEIVER The IC-7700 For Operators With A Common Vision of Design and Value. The essential elements for top-of-the-line HF transceiver performance begin with an exceptionall
2、y linear, low distortion design. Starting with electronic component selection, Icom integrates state-of-the-art analog performance with the latest digital technology to achieve superior receiver performance. As a result, the IC-7700 achieves More than 110dB dynamic range More than +40dBm IP3 More th
3、an +110dBm IP2 in the HF bands. Those who choose the IC-7700 will know they have the best receiver performance available. The IC-7700 will change forever what you expect as the normal sound of the HF bands. 110dB dynamic range and +40dBm 3rd order Intercept Point (IP3) The IP3 performance of a radio
4、 can be improved by sacrifi cing sensitivity, but Icom considers this a poor choice. To achieve REAL high-performance, Icom reviewed all of the analog re- ceiver circuitry. The IC-7700 employs mechanical relay BPF switching, a digitally tuned pre-selector, and three Hi-spec 1st IF filters (roofing f
5、ilter) in a clean and simple double-con- version superheterodyne de- sign. By balancing the analog and DSP functions, the IC- 7700 provides superior sensi- tivity simultaneously with a superb dynamic range of 110 dB, and +40 dBm IP3 (even in USB mode with 2.4 kHz filter bandwidth). Better than +110d
6、Bm 2nd order intercept point (IP2) An IP2 point of more than +110 dBm* means the 2nd order dis- tortion from strong broadcast stations will be completely elimi- nated. The endless pursuit of leading analog circuit engineering makes it possible to achieve this leading edge level of perfor- mance. * M
7、easurements were made using custom equipment, due to the limits of normal signal generators (SG) and duplexers to +85 dBm. The IP2 fi gure is a typical value. Double conversion superheterodyne system While multiple IF stages can become a source of distortion products and spurious responses, the IC-7
8、700 utilizes Icoms original image-rejection mixers in a simple double conversion superheterodyne. This reduces distortion and produces a much cleaner audio signal compared to triple or quadruple super- heterodyne receivers. High specifi cation inband IMD In-band IMD (Intermodulation Distortion)creat
9、es undesired spuri- ous signals as a consequence of non-linear processing of mul- tiple signals. All (2nd, 3rd or even higher)orders of IMD performance are superior in the IC-7700. The improvement will be especially evident in CW mode. Youll notice the difference as you copy weak signals without int
10、ernal distortion or noise. Inband IMD characteristics Band pass fi lter While some may lead you to believe that coils and capacitors are all created equal, at Icom we know design excellence. Rather than using switching diodes that can introduce distor- tion, the IC-7700 design utilizes high-grade me
11、chanical relays along with large capacitors and toroidal coils; resistant to mag- netic saturation, providing supe- rior linearity, and greatly reducing distortion. 3 Dynamic range characteristics (in 14MHz band) Audio output level Input level at the antenna connector dBm IP3 (3rd order Intercept Po
12、int) 3dB dB 50 40 30 20 10 0 Sensitivity 3rd order Intermodulation Noise floor level Dynamic range 110dB +40dBm INPUT dBm OUTPUT dB OUTPUT 14012010080604020120100806040200 100 150 200 250 50 IP2 (2nd order Intercept Point) +112.4dBm (224mV)(0.224V) Receiver Performance REF 20.0dBm *A_Write NormB_Bla
13、nk Norm10 dB/ REF 20.0dBm *A_View NormB_Blank Norm10 dB/ START 0HzSTOP 2.000 kHz *RBW 10HzVBW10HzSWP 40sATT 10dB REF 20.0dBm *A_Write NormB_Blank Norm10 dB/ START 0HzSTOP 2.000 kHz *RBW 10HzVBW10HzSWP 40sATT 10dB START 0HzSTOP 2.000 kHz *RBW 10HzVBW10HzSWP 40sATT 10dB S9 equivalent signal input S9 +
14、60dB equivalent signal input S1 equivalent signal input 110dB Dynamic Range and +40dBm IP3 Serious ham operators always try to advance their communication and technical skill and to improve their stations capability to the limit. The IC-7700s astonishing +40dBm IP3 capability will give you further b
15、ackup in these efforts. Contesting and DXing will be the absolute best with the IC-7700! DIGI-SEL (Digital pre-selector) The DIGI-SEL (digital pre-selector) is a very narrow, user ad- justable, pass band fi lter designed to automatically track the op- erating frequency, attenuating interference from
16、 out-of-band signals. While the pre-selectors pass-band remains centered on the operating frequency, on the fl y adjustments are possible via front panel controls. The DIGI-SEL is especially useful for multi-transmitter operation and near strong broadcast stations by reducing the 2nd, 3rd, and even higher order IMD compo- nents from other stations. Pre-amplifi ers The IC-7700 has a total of 4 pre-amplifiers, two for the HF bands and two for the 50MH
