IC-7200 Rugged manpack styling. Two type IF Filters. MAIN UNIT Design and architecture. Link to Test review Radcom Uk

IC-7200: Triple conversion superheterodyne system:
Intermediate frequencies 1st: 64.455 MHz, 2nd: 455 kHz, 3rd: 15.625 kHz.
(Clik for inlarge the MainUnit)

IF Filters type: a) DSF753SBF-D64006GQ 64.455 MHz 1st IF 4 Pole Roofing Filter 6kHz-BW 3dB – b) CFWS455HT 2nd IF Ceramic Filter 6 Elements Ladder Type, 6kHz-BW 6dB/ 18kHz-BW 50dB. —-  The MAIN UNIT is the core of IC-7200.
Test review Radcom UK  IC-7200 by G3SJX -—> Check the Link below

[Note - radiocronache.com®]
The roofing filter and the Ceramic Filter is not a ultimate selectivity on the this tranceiver. The designer uses the DSP process to define the selectivity of the receiver for each supported emission type. The purpose of the 6kHz roofing  filter reduces the statistical likelihood that strong undesired signals well outside BPFs, to suppress images produced in the first mixer. The Ceramic Filter on the 2nd IF 455kHz to suppress images produced in the 2nd IF mixer will enter the IF chain and over-range the ADC Codec. As long as  the ADC is operating in its linear range, the DSP IF filter will do its job.
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Design and architecture:

The RX signals are passed through one of 9 BPFs on the RF UNIT.  The BPF for 50 MHz band contains a separate Pre-amp to make up the loss for high sensitivity on this band. While the Main Pre-amp function is activated, the RX signals from the BPF are applied to the noiseless feedback AMP 2SC5551F. This Pre-amp provides low-noise, high RF gain and good IP characteristic. The amplified or not RX signals are entered to the MAIN UNIT, then applied on the 1st mixer 2SK1740 x4 junction FETs. A quad-structured 1st mixer circuit, provides high enough intercept point. RX signals are mixed with the 1st LO signals from the 1st LO AMP 2SC3357 to be converted into the 64.455 MHz 1st IF signal. The 1st IF signal is filtered by the 6kHz Roofing Filter (FI541 – FL421) to remove the RX frequency signal and 1st LO signals, and amplified by the 1st IF AMP 3SK264. The amplified 1st IF signal is applied to the 2nd duble balanced mixer HSB88WS to converted into the 455 kHz 2nd IF signal.
The 2nd IF signal is filtered by Ceramic Filter CFWS455HT (FI601) and amplified by 3SK264 x2 IF AMP and 2SC4081 BUFF, then applied to the 3rd mixer TS5A2053. – The converted 15.625 kHz 3rd IF signal are entered to the ADSP-BF532SBSTZ400 on the DSP section, passed through the (ADC/DAC) Codec AK4620B. – Digital IF DSP for: Twin PBT, Noise Reduction, Manual Notch, Automatic Notch, NB etc. –[radiocronache.com®]
Link to: Test review Radcom UK Jan. 09 by G3SJX (to-SRSAB.SE) PDF 1.5MB
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DE: IC-7200 moderne technik ZF-DSP. AGC-Schleife. Digitales ZF-Filter. Twin PBT. Digitale Rauschminderung. Der IC-7200 ist ein preisgunstiger, robuster Kurzwellwntransceiver inklusive 6 m im “military look” fur Einsteiger und insbesondere fur den Einsatz unterwegs.

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