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Belka-DSP

A shortwave receiver comes from Belarus which triggers the "must have" effect! The Belka DSP. Various videos have been circulating on YouTube from this device since autumn 2019. Once looked at, the above-mentioned effect occurs. The Belka-DSP is tiny! It is smaller than a credit card. Despite the very small dimensions, it is a full-fledged shortwave receiver with digital signal processing (DSP). This means that the operating modes and the filter bandwidths are software.

Its designer Alexander Buevsky (EU1ME) attached great importance to maximum portability during development. Therefore, no loudspeaker was installed in the Belka-DSP. Only a lithium polymer battery can be accommodated in the housing. The device must therefore be operated with stereo earphones, headphones or a small passive or active loudspeaker. He doesn't have a built-in antenna either. For this purpose, a 70cm long telescopic antenna with BNC connector is included. The Belka-DSP is very robust. The housing is made of high quality, black anodized aluminum. The voting button is on the right. On the left side you will find the BNC antenna socket, the 3.5mm stereo jack socket and a micro USB connection with an LED that shows the charging status. The large, white backlit LC display and four push buttons can be found on the front. The device lies comfortably in the hand and makes a high-quality impression.

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The most important key data of the Belka DSP

- Frequency range: 3.5MHz-30MHz (tunable from 1.5MHz)
- AM, AMS, LSB, USB, NFM, CW
- MDS (smallest audible signal at): -135dBm
- Dynamic range: 80dB
- Bandwidths: 2.4 - 2.7 - 3.0 - 3.5 - 4.0 - 4.7Khz (audio bandwidth)
- High pass to bandwidths: 50 - 75 - 100 - 150 - 200 - 300Hz
- CW bandwidth: 300Hz
- CW pitch: 500 - 600 - 700 - 800 - 900 - 1000Hz
- Frequency stability: 0.5ppm (TCXO)
- Signal strength display in dBV EMF
- 24bit ADC & DAC
- 32 memory locations
- 3.5mm stereo jack
- Operating voltage / charging voltage 5V (via micro USB socket)
- Built-in lithium polymer battery with 3.7V 2200mAh
- BNC antenna connector
- Dimensions: 84x50x20mm (WxHxD)
- Weight: 95g

Scope of delivery:
Belka DSP
telescopic antenna

Block diagram

 

The interior of the device is very neatly processed, which suggests that it is equipped with machines. The practiced eye does not miss the fact that the Belka-DSP reveals a little secret, if you take a closer look at the board. Bandpass filters can be seen on the upper left half of the red circuit board. This means that the small Belka DSP has a preselection in the antenna input. This also shows the block diagram above that the manufacturer provides. The large LiPo battery with 2200mAh has enough capacity for over 24h continuous operation of the device.

Working with the Belka-DSP

Although the Belka-DSP offers some functions and has only a few controls, it is still easy to use. Even inexperienced shortwave listeners will quickly get along with the little one. Experience has shown that similar developments by radio amateurs contained some shortcomings in operation. That is different with the Belka-DSP. Alexander Buevsky (EU1ME) built a device with logical and simple operation. As an example, the operating modes note the step size and the bandwidth that was last used. So you don't have to change the bandwidth every time you switch from AM to USB etc. The operating instructions are only available in Russian and English. I took some time and translated it into German. It can be downloaded from the following link.

Belka-DSP Bedienungsanleitung in Deutsch

 

 

 

The comparison on stationary antennas

Unfortunately I had no other portable receiver available in the test phase to make comparisons. That's why I let the Belka-DSP compete against a "big boy". His opponent was the Icom IC-R8600. Sure, it's like comparing a mosquito to an elephant. The Belka-DSP also had to demonstrate its ability on active station antennas.
So that you can get an idea of the reception performance of the Belka-DSP, I recorded a few audio comparisons.

Test conditions

Antennas: Datong AD370, Kreuzloop-Reuter RLA4 / E2, Sony AN-1
Comparison receiver: Icom IC-R8600
Both receivers are connected to the PC via an audio switch.
Recording software: Audacity - The audio files were not reworked. Cut to length only.

Audio comparisons

Differences between the receivers can best be determined with audio comparisons and not with the written word. Both receivers were set the same if possible. The station received was carefully selected so that it could be received as consistently as possible over the recording period so that the differences can also be assessed. A few audio comparisons are from stations on the sward, which means they are just above the noise floor. I therefore recommend using headphones.

Second 0 - 15: Belka-DSP
Seconds 15-30: Icom IC-R8600

3616khz-LSB
2.4khz
Hamradio
 3975khz-AM
6khz
Shortwaveradio
5025khz-USB
2.4khz
Rebelde.mp3
7850khz-USB
2.4khz
CHU-Canada
8776khz-USB
2.4khz
Olympia-Radio
9990khz-AM
6khz
Radio-Farda
10051khz-USB
2.4khz
Gander-Volmet
11815khz-AM
6khz
Brasil-Central
 
13264khz-USB
2.4khz
Shannon-Volmet

 

13870khz-AM
6khz
FEBC-Manila

 

14205khz-USB
2.4khz
Hamradio

 

15280khz-AM
6khz
Radio-Japan
17630khz-AM
6khz
Voice of Iran
28257khz-CW
0.3khz
Bake-DK0TEN
 

On the road with the Belka-DSP

I often had the Belka-DSP with me on long walks. One thing caught my eye. It is ultra portable! The Belka-DSP literally fits in the tight pocket of your jeans. I don't know of any other receiver that is so small. Of course, the telescopic antenna and the stereo- earphones must be taken along. The reception with the small Belka DSP is really fun. It is low-noise, selective and has a balanced audio reproduction. Battery capacity was not an issue. The battery easily lasts 25 hours. Two things weren't so good after all. If the outside temperature is cold, the response time of the LC display is very slow. During portable operation with a directly connected telescopic antenna, it was noticed that the Belka-DSP had a few more whistling points than with a remote antenna. This is actually normal, but sometimes it was a bit annoying when the whistle was exactly on the transmission frequency of a station.

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Conclusion

The little Belka-DSP surprises and puts you in a good mood! No signs of overload were found during the test phase. And that on stationary active antennas. Despite its very small dimensions, the Belka-DSP has a preselection. The reception quality can be heard. Compared to the Icom IC-R8600, it does not have a particularly high-pitched audio reproduction, which reduces the intelligibility somewhat for weak transmitters, but makes listening more pleasant. The sensitivity is almost at the level of the IC-R8600 and is constant up to 30MHz. Portable operation is fun, except at low outside temperatures. Then the display reacts very slowly. When the telescopic antenna is directly connected, some whistling points are noticeable. For remote antennas, this was largely not a problem.
Top workmanship, very good reception at a very fair price.

Available from: http://www.belrig.by/

posted: 14.02.2020

 

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