IC-R9500

The ICOM IC-R9500 is an wide-band receiver in conventional technology with regard to the frequency conversion structure while it is digital in the last IF for filtering, demodulation and signal processing. It incorporates two 32-bit processors (DSP), one employed in the receiver circuit and the other for the spectrum analyzer function. The LCD display offers indeed a selectable view in two modes. In normal form the excursion can be set in the range between ± 2.5 kHz and ± 5 MHz, this allows to observe in detail the signal even if close to stronger emissions. In the panoramic form, on the other hand, the radio-propagation situation can be determined as well as the evolution in a wide band. The possibility of adjusting the excursion limits or centering it on the reception frequency has also been provided. The positioning function on the peak signal is also available.

There are five filters in the first IF (roofing filters) that depending on the operating mode can be selected between the values of 3, 5, 15, 50 and 240 kHz. The final selectivity is instead determined by the digital IF filter characterized by an excellent form factor, of course the bandwidth can be adapted continuously according to the needs. Two notch filters with an attenuation of 70 dB can be inserted and positioned in order to suppress interference, this manual action is added to the auto-notch function. Even the noise-blank is part of the DSP, the user can create two intervention profiles by choosing the width of the attenuation peak, the depth and the time duration.

The receiver has the synchronous AM mode with the possibility to choose the sideband for demodulation (LSB or USB). Pass-band tuning (PBT) with independent adjustment of the lower and upper cutoff frequencies of the filter. The AGC time constant, IF gain, squelch, audio digital noise reduction (DNR), audio bass / high tones can be adjusted via rotary control. 10 independent VFO where you can record frequency, operating mode, filter width and other settings. Digital audio recorder to store the listened radio traffic, maximum duration of about 1 hour in high quality mode. Memory with a total of 1000 locations grouped in banks, independent controls on the front panel simplify the recall and management while with a standard keyboard connected to the USB port you can type the names to be associated to the various frequencies. The tuning setting can be done by rotary control, with direct input from the keyboard, or even via remote PC. Multiple search options: between band limits, within memories, on a priority channel, according to the mode, with auto-memory write. Scan speed 40 memories per second. VSC function to unlock the squelch in the presence of a modulated carrier. Automatic frequency control in FM mode, automatic tuning capability for CW and AM modes.

IC-R9500 ICOM rear panel

The apparatus is designed to be interfaced with various external systems both for management tasks and in support of reception functions. Fot this the rear panel has several connectors, of various types, intended for specific wiring. It is also possible to customize the parameters for certain lines.

IC-R9500 performance and practical notes :

Undoubtedly the performance in terms of dynamic-range make the ICR9500 very well equipped for every kind of listening, even in the presence of strong signals separated by a few KHz while the wide range of parameters on which the user has the right to intervene allows to fully exploit the potential of RF front-end circuits. An in-depth analysis of the features expressed by the apparatus requires direct experience in various operating conditions and extended over a long period of time. Here we limit ourselves to highlighting some details not sufficiently described in the official notes drawn up by the manufacturer and his distributors.

The ICR 9500 adds in the FM mode an unusual bandwidth obtained with the help of the roofing filter of 50 KHz, this value has been inserted among the options as it adapts to the reception of WEFAX satellite signals (APT meteorological maps). Moreover, from the practical side, this selectivity value allows - for example - to enhance the listening of WFM emissions in the presence of interferences on adjacent channels. The listening technique, which is based on the fact that fragments of the programming modulating the carrier only partially with low frequency deviation, radically extends the possibilities of monitoring in the band 87.5~108 MHz making the receiver an interesting tool for FM DX. Remaining to the specificities of the reception modes, it is useful to remember that the decoding of the P25 format, for which the installation of an optional module is required, is virtually useless in certain country due to the fact that this standard (editor's note: digital system PMR) has its main spread on the North American continent. Another detail worthy of attention is the availability on a line, the connector is positioned on the rear panel, of the clock generated by the oscillator inside the apparatus - in the same way an external clock can become the master reference. Access to this signal makes it possible to wire an integrated system with accessories such as down-converters, expanding reception capacities towards microwaves while maintaining full frequency coherence and stability.