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In 2014, Expert Electronics from Russia presented their first pure SDR receiver, the ColibriDDC-SDR. A small box with respectable reception performance and good operating software. Now follows the little brother ColibriNano. This is extremely small! Probably the smallest Direct Sampling SDR. At the first sight I thought, already again a RTL stick! But far from it ...

The Hardware

If you hold the "USB stick" in your hand, you will be pleasantly surprised. The housing is made of milled aluminum. It is black anodized and neatly processed. The small one is simple and noble. To get a view of the innards, I opened the ColibriNano. I do not have to lose many words. The electronic board is cleanly processed. The aluminum housing is designed in such a way that the individual modules on the board are located in a separate shielded housing. Cleverly solved! The ColibriNano is a full-fledged SDR, which ultimately turned out to be on closer inspection.

The tiny one gets quite warm during operation. 43C. I measured on the housing. In order to reliably dissipate the produced heat, a heat-conducting foil was placed on the 14-bit A / D converter, making contact with the aluminum housing. Other SDR's are similarly warm at the base. This is not the case, because their housings are considerably larger and the heat is radiated better.



The most important technical data

- Operating modes: LSB / USB / DSB / CW / AM / SAM / NFM / WFM (software dependent)
- Frequency range: 10KHz - 55MHz
- Frequency range in undersampling mode: 10KHz- 500MHz
- Sampling rates with 24-bit resolution: kHz 48, 96, 192, 384, 768 (visible spectrum width)
- Sampling rates with 16bit resolution: kHz 1536, 1920, 2560, 3072 (visible spectrum width)
- Sensitivity: 0.35uV
- Dynamic range: 110dB
- Operating voltage 4.5 ... 5.5V (directly via the USB connection)
- Power consumption: 0.41A
- 14bit ADC
- ADC clock frequency: 122.88MHz
- Stable local oscillator with +/- 0.5ppm
- attenuator / preamplifier in 0.5 dB steps adjustable from -31.5 to + 6dB
- Antenna input with 15 kV ESD protection
- SMA antenna connection
- Dimensions L x W x H: 90х25х17mm
- Operating temperature: +45 ... + 50 C
- Weight: 43 grams

Block diagram of the ColibriNano


Connection and commissioning

Because the ColibriNano is designed as a USB stick, it is connected directly to a USB port of the PC or notebook. In the latter I recommend a USB extension cable with about 30cm length to use. The ColibriNano has a certain weight and could, with a horizontal position over time, the USB jack of the notebook can unclog. I myself use a USB hub, where the plugs are inserted vertically from above. Also for the antenna connection you should get a 50cm long Pigtail adapter from SMA to BNC / PL. Best from RG174 or RG316 to minimize the pressure on the USB port.

Once these preparations are done, the installation of the ExpertSDR2 program for the ColibriNano is done.

This takes a few moments. Normally the software should recognize the ColibriNano and address it. The manufacturer points out that if other USB devices are connected with the same USB chip from FTDI, there might be problems with the detection of the ColibriNano. For this there is a special procedure which is in the installation manual. For me everything worked smoothly on Windows 7 and 10.

The software ExpertSDR2

As with the big brother ColibriDDC-SDR, the proven same software is used here as well. Apart from a few functional restrictions, such as the wideband spectrum, the vast majority of functions are the same. Since the test of the ColibriDDC-SDR in 2014, no more functions have been added. Would not be necessary. The software has all the necessary functions for a successful reception. Only software errors have been corrected.

Communication with external programs often runs via VAC, the virtual audio interface. This time I took CW-skimmer and the interplay between both programs tried. For CW-Skimmer and ExpertSDR2 to talk to each other, a few settings must first be made on both programs and on VAC. Here is a guide. < Link > After the settings are made, the communication between the programs will work smoothly. You can adjust the frequency in both programs. On the ExpertSDR2 everything can be adjusted according to your own wishes. The software can also make tape recordings. The I/Q-files are then played with a separate software which can be downloaded from the manufacturer's website.


The ColibriNano can also be controlled remotely via the Internet. Either you connect it to a PC/notebook, or you have the possibility to connect the ColibriNano to the router via the microcomputer RasperryPi3. Unfortunately I could not test this function for time reasons. Information about this can be found under the link. <Link>

It can also be operated with HDSDR and SDR-Sharp. Expert Electronics provides the required ExtIO's on their website for download. Unfortunately, the provided ExtIO's did not work as they should. There are still many errors. That is why I have not entered into this.

The reception with the ColibriNano

Due to its dimensions it was not to be expected that the ColibriNano had a preselection installed in its housing. It is only a low-pass filter installed at 55MHz. Nevertheless, I treated him like any other candidate. He was operated at the crossloop, at the big loop with 8m circumference with the amplifier NTi ML200 and at the Datong AD370.

The clipping indicator often lit up. This fact is often overestimated and the recipient's performance is unduly diminished. But this is not the case in most cases and leads to a false impression. As long as the clipping indicator does not light constantly and no intermodulations or increased noise are heard, the ADC is not overloaded. During the entire test phase of two months, I have not noticed a single audible intermodulation. It is obvious that such a device has not been designed to be operated on extremely high-frequency antennas such as Beverages or Beam's. The clipping display of the ColibriNano can be deactivated by right-clicking on the S-Meter.

How is the ColibriNano now? Without circumlocution and in short, very good! In almost all situations, the small one could match the comparison device. The sensitivity is almost equal to that of the Winradio G33DDC. From VLF up to the 10m volume all transmitters were received, the G33DDC also received. This is also thanks to the excellent ExpertSDR2 software. It is matured and offers a lot of possibilities for interference suppression. The limiting factor is antenna compatibility. Hobby antennas such as ALA1530, MiniWhip etc., the ColibriNano tolerates. Larger antennas require a solid preselection.

In Undersampling mode the ColibriNano receives up to 500MHz. FM even in stereo. This works quite well, but should be enjoyed with caution. For the frequency ranges above 55MHz, he has not installed any bandpass filters, which can lead to intermodulations.

But now to the reception comparisons! During the tests I took the Winradio G33DDC as a comparison device, although the price difference between these two devices is very high. Actually, the KiwiSDR, which costs almost the same amount, would be the right comparative candidate. Because the KiwiSDR has a different operating concept, I decided to take the G33DDC.

Audio comparisons

Second 00 - 10> Winradio G33DDC
Second 10 - 20> ColibriNano
Some recordings are of very weak, barely perceptible channels. Only in this way can differences in sensitivity and intelligibility be heard at the grass mascara in order to find the DX capability of the device. Therefore, I recommend using a headphone to listen to the subtleties.

At the current lowest active frequency 18.3KHz, the French military transmitter "HWU" is good to hear. Reception antenna here was the Datong AD370. Both devices were able to receive the transmitter. Thanks to its excellent NB's (Noiseblanker), the ColibriNano has been able to provide the better result as far as the visibility of the signal in the spectrum is concerned. The spectrum is largely freed from the horizontal interference bands. The G33DDC delivered the better audible signal with more resolution. The NB's of the G33DDC unfortunately do not affect the spectrum, which led to a poorer signal recognition. However, the spectrum of the G33DDC has a higher resolution than the ColibriNano software.

HWU 18.3KHz


Due to strong local disturbances I could not make clever comparisons on LW and MW.

↓ Hamradio 80m Band.

Hamradio 3752KHz

↓ Radio Rebelde in SAM at 7am.

Radio Rebelde 5025KHz

↓ Radio MiAmigo on 6085KHz with nice Music. Both SDR's in AM-Synchron.

MiAmigo 6085KHz

↓ Hamradio 40m Band.

Hamradio 7150KHz

↓ Echo of Hope from Korea on 9100KHz  in AM-Synchron.

Echo of Hope 9100KHz

↓ ItalCable on 10MHz in USB. Both SDR's on par. Only with slightly different accents.

ItalCable 10'000KHz

↓ RAF Volmet on 11253KHz in USB. Bandwidth 2.7KHz. The ColibriNano brings a somewhat muffled reverberation, but with less background noise.

RAF Volmet 11253KHz

↓ All India Radio on 13605KHz in SAM. The ColibriNano roars a little more. Probably because of the missing preselection.

All India Radio 13605KHz

↓ Hamradio 20m Band.

Hamradio 14157KHz

↓ Radio Pilipinas on 15190KHz in AM without Noiseblanker.

Radio Pilipinas 15190KHz

↓ Voice of America in french on 17650KHz in SAM. No big differences on this signal with S5.

VOA 17650KHz

↓ Hamradio beacon auf 28257KHz in CW.

Hamradio 28257KHz


Expert Electronics has managed to build the smallest direct-sampling SDR. The small device, with the small dimensions of a USB stick, delivers excellent reception performance on hobby-standard antennas. For 300 purchase price you can do nothing wrong.

Top product!

Posted: 24.07.2017


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