I got my hands on the Retekess V115 receiver (also known as the Tivdio V115, Kaimeda SRW-710S Mini, Audiomax SRW-710S, VR-robot WC-710S, and HanRongDa K-603) version F9205A when I ordered it on AliExpress to replace my lost Tecsun PL-310ET. I needed a compact and affordable all-wave MW-HF-VHF-FM receiver with direct frequency input and good sound.

Purchase

I ordered a V115 receiver from the official Retekess store for 1,220 rubles. The hyperlink was removed on August 31, 2023, to avoid violating Federal Law No. 274 of June 24, 2023, "On Amendments to the Code of the Russian Federation on Administrative Offenses," paragraph 16 of the Law (administrative liability: for failure to provide information about online advertising to Roskomnadzor). The law comes into force on September 1, 2023.

Delivery is free. The order was placed on May 6, and the receiver was delivered by courier to my home on May 11. The total delivery time was 11 minus 7 days = 4 days.

Packaging and equipment

The RETEKESS V-115 receiver came in a white cardboard box.

Inside the package - instructions in English, BL-5C battery, MiniUSB cable for charging from an adapter 5V and the receiver itself.

The receiver is small, fits in the palm of your hand and fits in any pocket. It's the size of a pocket dictionary.

Battery - BL-5C with a capacity of 1000 mAh.

It is enough for 10 hours of listening at the average volume. The charging is slow, from the adapter 0.5-1a, takes about 2.5 hours. (Fast charges 2A forbids to use).

At the first turning on, a greeting appears, then the receiving frequency of 4.750 MHz is turned on.

Looking ahead, the receiver has a continuous settings range from 4.750 to 21.8 MHz, without passes. Modulation am, step 5 kHz.
There is also a range of FM 87.5-108, which can be switched through the menu by 64-108 MHz. Step 0.1 MHz.
In the range of medium waves, the step of 9 kHz (for the eastern hemisphere - the ITU region 1).

First of all, the sound for such a small receiver is surprised - pure and with a confident baritone. Noticeable on percussion instruments and double bass. Songs, pop music are also compared to the "flat" sound of Tecsun, on V115 they sound volumetively. Here a small phase -inverter is used on the rear panel of the case. But "tambourine" and resonances of the case are absent, I do not notice them. The maximum volume is high, there is no distortion.

Departure to the nature of May 14, 2022

The tidy of relatives to the garden is May to plant potatoes. At the same time, I checked the receiver when working on the built -in telescopic antenna. Also, it was necessary to learn how to manage the receiver.

The case on the right side face has no buttons - but the rich capacity of connection:

• headphone connector 3.5 mm
• Line input "Line in" (the receiver can work as an external column)
• Memory card slot
• Charging connector from a cellular adaptermicrOUSB
  

On the rear panel - the battery compartment, the ability to install a rack for listening on the table, exit the subwoofer.

RETEKESS V-115 receiver has three settings modes:

• Automatic search for stations throughout the range : it turns on the long -term retention of the central button "playing / pause" with memorization of the frequencies of radio stations in memory (while the old purposes are wiped - this function is not an ETM duga, since the receiver is inexpensive, the search is somewhat simplified).
• Change sq range with the SW button, then scanning up or down inside the range , the stop occurs at the next radio station.
• manual frequency input with a digital keyboard 1.2.3,4,5,6,7,8,9,0 and confirmation by the "input" Pupil / pause with the ** "input" button.

Volume adjustment - key in the form of a swing: " -" down and "+" up.

There are no control handles, like the +5 kHz buttons. Therefore, at the first moment, control makes confusion, but then you get used to setting frequency using buttons you begin to control the receiver quickly. (Frequency introduction with digital frequency buttons and confirmation of the “playback/pause” key). From my point of view, the buttons are more durable than variable resistors or a hallcode.

There is a "menu" button - with long retention, we get into the settings settings. You can change the step in the range of medium waves of 10 or 9 kHz, choose a language - there is Russian. Also, I recently found the possibility of turning on the "Soviet VHF" from 64 to 74 MHz.

At the VHF radio stations are entered when scanning to the Bank of Memory. Each scan that the user launches long -term retention of the "playback / pause" button rewrites the cells of the bank. There is no temporary memory of ETM here, but this is not a remark, given the price. There is a function of removing the contents of the memory cells (if the receiver scored the cells with weak stations or interference, these cells can be cleaned). After removing the frequency from the memory, the remaining cells retain their numbers.

Radio stations can be called as channels in a conventional radio station with buttons, for example 23 and "entry" (playback / pause). Or enter two digits and wait for 6 seconds.

When taking short waves on the built -in pin antenna in the absence of passage, the internal noise of the receiver is heard - a muffling with a frequency of 25 Hz. (At first I was even upset because of this).

The recording was made at 09:33 UTC, frequency of 17650 kHz - Radio China to Europe. Crack is heard - internal interference from the processor and digital lines.

In the future, as it turned out, the reception is excellent in the evening ranges of the SW4-SW5 when the signal force from the antenna crushes the internal interference. This will be described in the next article about use of the external antenna.

Reception of local FM VHF stations is impeccable. Record from the dynamics of RETEKESS V-115 on a mobile phone record without processing.

Add dated May 17 about receiving weak wings transmitters

Sensitivity in the FM range is sufficient for 100% reception in the city of all radio stations. From a room in a deep "shadow" subjectively, taking better than that of Tecsun. In the range of "Soviet" VHF, it is also subjective to take 2-3 times better than that of Tecsun PL-310et.

However, in an open area 10 km from the city, the reception of distant, weak radio stations in the FM range are interfered with powerful local transmitters, from which numerous weak "phantoms" are heard at free frequencies - duplicate, by ear with a level. Obviously, for DX reception at VHF, you need to leave kilometers for 50-60 per city, where the influence of transmitters from the metropolis is reduced. The receiver of a higher class (for example, in a car radio) copes with the reception and in the city, does not overload.

According to ham N9EWO in article on QSL.NET the AKC 6951/6955 microcircuit from the Japanese company ETC is used instead of the American Silicon Laboratories Si 473X.

Sensitivity according to datasheet:
* AKC 6951 - 7 dbuv = 2.2 uv * (at mod = 22.5k ref. Out, sinad = 30 db)
Si 4730 - 1.1 UV ** (with (s+n)/n = 26 db).

Radio recording in mp3

Charging the battery

Charging is best donemicro USB with a slight current charging by a small current - 0.5 ... 1 ampere.

Links:
RETEKESS V115 user manual on English on the official website
V115-EN,DE,FR,ES,IT.pdf.

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