WR-G31DDC Excalibur | WiNRADiO

WiNRADiO » WR-G31DDC Excalibur

PC controlled direct sampling SDR receiver. Frequency range 0.009-50 MHz all-mode, supports wideband spectrum record/playback up to 2000 KHz bandwidth. Ideated in USA.

Reference market : ham-radio

General :
Frequency coverage 0.0090 ~ 49.9950 MHz
Modulation mode CW / LSB / USB / AM / AM-S / FSK / FM / DRM [1]
Tuning step 1 Hz min
Receiver :
Sensitivity CW
500 Hz
20 uV (0.01 MHz, 10dB S+N/N)
3.2 uV (0.025 MHz, 10dB S+N/N)
0.56 uV (0.05 MHz, 10dB S+N/N)
0.36 uV (0.1 MHz, 10dB S+N/N)
0.16 uV (0.2~50 MHz, 10dB S+N/N)
2100 Hz
0.35 uV (0.2~50 MHz, 10dB S+N/N)
AM 2.0 uV (0.2~50 MHz, 10dB S+N/N)
FM 0.56 uV (0.2~50 MHz, 12 dB SINAD)
MDS (Minimum Detectable Signal) -130 dBm (10 MHz, 500 Hz BW)
Selectivity 0.01 ~ 62.5 KHz user-defined [2]
A/D conversion Freq. 100 Msps
Res. 16 Bit
Sampling out 20 ~ 2000 Ksps [3]
RF attenuator 0 / 3 / 6 / 9 / 12 / 15 / 18 / 21 dB
NF (Noise figure) 14 dB (0.2~50 MHz)
Dynamic range 107 dB
IP3 (3rd order intercept point) +31 dBm
Image rejection > 90 dB
Frequency stability ± 2.5ppm with temperature from 0°C to +50°C
Frequency accuracy ± 0.5ppm at +25°C
Features :
Memory Unlimited memory channels
Antenna SMA 50Ω connector [4]
Power supply 11~13 VDC external
Power consumption 500 mA typ
45 mA power save
Connections USB2.0
Mechanical and environmental data :
Operating temperature from 0°C to +50°C

[1] DRM mode optional
[2] With 1 Hz steps
[3] In 21 steps
[4] SMA / BNC adapter provided

Description :

The EXCALIBUR, or WR-G31DDC, by WiNRADiO is a software-driven receiver (Software Defined Radio) with high performance and moderate cost, developed to cover the frequency range from 9 KHz to 50 MHz. The signal acquisition via DDC takes place in a wide instantaneous bandwidth up to 2 MHz. This segment is available for recording the RF spectrum, for demodulations, and also for further processing by the software. Three independent demodulators can be activated within the acquired band, this allows to follow more radio channels and therefore more signals at the same time. The internal architecture has at its center an analog-to-digital converter (ADC) operating at 100 Msps, in other words 100 million samples per second, with a resolution of 16 bits. The combination of a high dynamic preamplifier at the input of the converter determines remarkable performances on the resistance to the intermodulations, moreover the advanced use of the dithering technique - used to subtract energy from the discrete components generated by the ADC in its operation - allows to eliminate the spurious without conditioning the sensitivity. The spurious free dynamic range (SFDR) reaches as much as 107 dB, a clock phase noise of -145 dBc/Hz @ 10 KHz extends the integrity of that performance even at small frequency offsets.

The EXCALIBUR includes a real-time spectrum analyzer operating in the entire receivable range of 50 MHz with a resolution of only 1.5 KHz. This function in the graphic interface is active together with the analyzer dedicated to the band acquired via the DDC and to the tuned channel band. This feature offers an elegant overview that is very effective in monitoring radio signals and, of course, the user has the possibility to set the various parameters with absolute freedom.

EXCALIBUR, software interface

There are different configurations for the spectrum analyzer, in addition to the standard display you can opt for cascade mode also zooming on limited frequency portions in order to focus on the details. The part acquired by the DDC is shown highlighted in the display, this can be selected via the keyboard or mouse and then shown in another window within which three independent channels can exist. For each channel the user manages selectivity, IF-sfift, PBT, notch and other functions while the demodulated audio spectrum can be observed.

Also being a receiver with articulated functions the WR G31DDC proves easy to use with an intuitive interface that gives access to all the primary functions and control utilities such as noise-blanker, memories, squelch (level or voice activated), various tuning options, modes, support for lists of frequencies in EIBI and HFCC databases. The device has a USB 2.0 port for connection to the computer, integrated in the hardware there is a high-pass filter with a cutoff frequency of 1.8 MHz (attenuation of 60 dB minimum at 0.5 MHz) insertable if in your area are present high-powered medium-wave stations. With the aim of minimizing electrical noise, the EXCALIBUR power supply is linear, non-switching. Requirements for the PC are a dual-core 2 GHz CPU or higher and Windows XP or later operating system.

Performance and practical notes :

This WiNRADiO model brings together many of the real performance that DXers are looking for an advanced SDR HF radio system. Excellent technical features and usability of the controls with their balancing, a sign of a high-end project, give the user great potential in demanding receptions without adding complexity to the allocation of functions. Due to its excellent performance the WR-G31DDC was named best receiver in 2011 by the well-known WRTH publication. The only negative aspect is the lack in the software package supplied with the DNR function, the digital noise reduction through processing algorithms, for which the installation of an auxiliary program is required. For the more demanding it is also available the model WR-G33DDC EXCALIBUR Pro as advanced version of this receiver, the main differences are:

  • Acquired bandwidth from 2 grow to 4 MHz
  • New low-noise preamplifier
  • Addition of a preselector with configurable filter bank
  • Selectivity adjustable up to a minimum of 1 Hz instead of 10 Hz
  • Frequency stability increased to ±0.5ppm
  • Pause function
  • Addition of T&M (measurement) functions
Valuation :

Dynamic range
Spurious response
Signal functions
Control functions
User friendly

Stars: 1=insufficient, 2=just sufficient, 3=mediocre, 4=good, 5=excellent

Review :

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