The WJ-8711A is a fully synthesized, general-purpose HF receiver for monitoring RF communications from 5 kHz to 30 MHz with 1-Hz tuning resolution.
By combining analog and digital signal processing (DSP), the WJ-8711A achieves high performance at low cost.
DSP techniques accomplish functions such as noise blanking, IF filtering, AGC, demodulation, Beat Frequency Oscillator (BFO) and passband tuning.
Filters with superior amplitude and group delay characteristics are achieved with digital stability and repeatability. The receiver has 66 standard selectable IF bandwidths.
Available detection modes are AM, SAM, FM, CW, USB, LSB and ISB. An operator can adjust the tunable BFO in 10-Hz steps over a +8000 Hz range, and the available passband tuning further enhances the reception of CW signals. Gain control is manual or automatic, with fast, medium, and slow AGC modes. An operator can adjust the squelch threshold from 0 to -135 dBm, or disable it. Enabling the noise blanking feature effectively eliminates the adverse effects of impulsive noise.
In addition to fixed-frequency tuning, the WJ-8711A provides fast, flexible scanning in three modes: channel scan, F1-F2 scan and F1-F2 scan with lockouts. Dwell times are available for all scan modes from 0.5 to 20 seconds or infinite. The channel-scan mode provides 100 programmable memory channels. The operator can specify sectors of memory for individual channel
scans, allowing the subdivision of available memory into multiple search scenarios. Operators can specify that the receiver skip certain channels without deleting them from memory. Memory channels can also be single-stepped manually. In both F1-F2 scan modes, the step size is user-selectable from 1 Hz to 25 kHz. The receiver can store up to 100 independent frequency lockouts.
An operator can control the WJ-8711A locally via the front panel or remotely via the serial interface. Measuring 5.25 x 19 inches, (13.34 x 48.26 cm), the microprocessor-controlled front panel provides a user-friendly operator interface with dedicated, logically arranged controls and large, easy-to-read LED displays.
Frequency coverage from 5 kHz to 30 MHz in 1-Hz steps.
High dynamic range: +30 dBm 3rd-order intercept typical.
Digital filtering provides 66 IF bandwidths up to 16 kHz with exceptional shape factors.
AM, SAM, FM, CW, USB, LSB & ISB Detection Modes Standard.
Fast, flexible scanning with 100 memory channels.
3 variable AGC decay settings.
Noise blanking & passband tuning.
Tunable IF Notch Filter.
Internal switchable preamplifier & attenuator.