WiNRADiO G303 Demodulators

G3 - the third generation G303 demodulators are DSP software plug-ins which fit into the G303 control panel. All the last IF (intermediate frequency stage) and the demodulation stage functions are performed in software. Having been freed from hardware constraints, this brings about unprecedented level of flexibility and performance to the receiver.

The G303 is being introduced with two demodulators, with others to follow. The Standard Demodulator is included as a standard part of the package, while the Professional Demodulator is optional.

The G303 Standard Demodulator provides excellent performance with minimum adjustable paramaters, and facilities exceeding those of a demodulator of a conventional shortwave receiver in this price range (such as real-time spectrum scope).

The optional Professional Demodulator goes yet another step further and offers additional demodulation modes, and fully user-adjustable demodulation parameters, complete with interactive block diagrams of the internal structure of the demodulator, an additional dual real-time spectrum scope with vector voltmeter, SINAD and THD measurement, and many other facilities. This is a serious tool for a serious experimenter.


G303 Standard Demodulator

G303 Standard Demodulator

This demodulator is supplied as part of the G303 receiver package. It features AM, AMS (synchronous AM), AMN (narrow band AM), LSB, USB, FM3 (3 kHz FM), FM6 (6 kHz FM), FMN (15 kHz FM) and CW modes, with fixed bandwidths.

There is a real-time spectrum scope which shows the actual situation on the received band.

An interesting feature is Audio AGC (in addition to the existing hardware IF AGC).

Clicking the Setup button, another window opens, making it possible to adjust the necessary minimum number of parameters for optimum performance:

G303 Demodulator Set-up

The user adjustable parameters include the sound card selection, sampling rate (48000 samples/sec is recommended, 44100 can be also used), and the sound card input gain.

A clipping (input level overload) indicator and a CPU usage meter are also provided for the user's convenience.

With a minimum of initial set-up, the demodulator (and so the G303 receiver) are ready to go!


G303 Professional Demodulator

G303 - Professional Demodulator

This advanced demodulator is offered as an optional extra. It adds DSB and ISB modes, additional Audio AGC settings and continuous IF bandwidth adjustment (from 1 Hz to 15 kHz). There are also user-definable IF bandwidth preset buttons at the bottom.

Many more exciting facilities are hidden under the Setup button: Optimized filter settings make it possible to increase the receiver sensitivity typically by 2 dB on AM, SSB and FM; and by up to 10 dB on CW.

G303 - Professional Demodulator Set-up

The left part of the Setup window is similar to the Standard Demodulator. The right one contains some surprises: The demodulator parameters (such as the digital filter length) can be adjusted by the user. There are separate "tabs" for independent setting of each of the eleven demodulation modes.

Clicking on the View Demodulator Structure button discloses an interactive diagram of the demodulator structure:

G303 Professional Demodulator Structure (AM)

At the top there is a block diagram showing the structure of the currently selected demodulator (each modulation mode has its own demodulator). Below, there are also two spectrum analyzers. Left clicking on any of the color points inside the block diagram will connect the left spectrum analyzer to the associated point (the color of the point will change to red). Right clicking will connect the right spectrum analyzer (the point color will turn blue).

At bottom left, there is a Vector Voltmeter showing amplitude and phase differences between the two selected points, at the cursor frequency.

There are also THD (total harmonic distortion) and SINAD (signal-plus-noise-plus-distortion to noise-plus-distortion) meters, to complement this unique instrument.

The G303 Professional Demodulator can be purchased as a separate option, or bundled together with the WR-G303 receiver with a cost advantage. The model number of such bundled product is WR-G303i/PD (PCI version) or WR-G303e/PD (USB version). As a separate option you can order it directly via our Direct Download server.