Our model PI-892HF spectrum display processor accepts the 455 kHz intermediate frequency (IF) output from an HF receiver and processes the signal to create an IF pan display on a customer-furnished PC or workstation. The basic elements of the unit include an embedded PC, A/D converter, and a digital tuner that computes averaged FFT, spectra and transfers the spectral data over a network for display. The unit accepts control over the same network. The PI-892HF includes an IF switch that allows the user to select one of up to six receivers to monitor.
The PI-892HF can compute various FFT sizes (1024, 2048, or 4096) and corresponding spectral resolutions, as well as a selectable amount of averaging (1 to 127 spectra in block mode or persistent attack/decay.) Various window functions are available for the FFT, including Boxcar, Hanning, Hamming, and Blackman-Harris. The primary spectral display is 48 kHz bandwidth centered at 455 kHz. A secondary trace displays a 4 kHz segment of the 48 KHz display as selected by the operator. This allows for simultaneous display of the normal and zoom spectra.
The PI-892HF is designed to detect and display short-duration signal bursts. The averaging modes, windowing, and FFT overlapping contribute to optimizing this type of detection. For example, the unit will detect a 250 ms duration CW signal at a level at least 10 dB above the noise floor (within the bandwidth of the display window), and present a display of the signal on the screen for a minimum of one second.
The embedded PC is a PC-104 format board. This format provides an industry-standard ruggedized, compact module that supports a wide variety of peripherals. A high-speed digitizer and digital tuner board comprise the remaining processing elements. The PC runs a Linux operating system that provides for ease of adaptability to new platforms, ease of driver integration, stability, and high performance.
For further information please contact:
Reston Special Programs
Tel: +1 703-476-6500 Fax: +1 703-476-5010
