Heil Sound Parametric Receive Audio System Equalizer (PRAS EQ)

The Heil Parametric Receive Audio System Equalizer (PRAS EQ) is a state-of-the-art audio processor that enhances the internal audio systems of amateur radio, shortwave, commercial, and CB receivers. The PRAS EQ allows radio operators to modify, shape, and improve the audio output of their receivers using three separate equalization controls.

Midrange frequencies are the most critical for achieving clear voice articulation in receive audio. The PRAS EQ allows operators to have unique control over these important frequencies. First, operators can adjust the parametric midrange filter (MID FREQUENCY) from 400 Hz through 4 kHz, with the recommended sweet spot being at 2.5 kHz. In addition, operators can control the presence of these midrange frequencies plus or minus 15 dB using the MID GAIN control. Combined with a low-frequency filter (LOW) set at 160 Hz, and a high-frequency filter (HIGH) set at 6 kHz, the PRAS provides operators unparalleled control and quality of their receive audio.

Featuring three audio input and three audio output connections, the PRAS EQ is an excellent addition to any rig, and is especially useful in pulling out weak or noisy signals in DX and contest work.

The PRAS EQ is intended to be used with the Heil HPS-5 powered speaker (the PRAS EQ must be used with a powered speaker). For headphone use, the PRAS EQ also features two independent headphone amplifiers, each with its own 1/8” output and level control. The headphone outputs do not bypass the external audio out connections.

The PRAS EQ is powered by a 12-volt, 2 amp DC power supply (not included). A 2.5 mm barrel to powerpole adapter cable is supplied that is compatible with common 12-volt, 2-amp DC power supplies.