.

The mysterious SFP1000 socket

Put simply, the SFP1000 module allows the RSR200B to be operated either via a standard RJ45 Ethernet cable or a fiber optic cable. With the fiber optic version, a counterpart at the other end of the fiber optic cable is essential so that the light signal can be converted. This is unlikely to be used in the hobby world and is more likely to appeal to professional users.

Block diagram and functionality of the RSR200B

The signals coming through HF1 and HF2 pass through a 66 MHz low-pass filter (LP). VHF has a 66 MHz high-pass filter (HP). These attenuate signals from other frequency ranges to prevent crossovers. An antenna control (RS-232) can be activated upstream, allowing active antennas such as the RLA4 and/or the RAP1 & RAP2 preselectors to be controlled remotely. Conventional active antennas with a 12V operating voltage can also be supplied via this control. The signals then pass through amplifiers and adjustable attenuators before reaching the ADCs. There, the signals are digitized and forwarded to the FPGA. The FPGA preprocesses the signals and then forwards them to the PC via the USB3 and/or LAN interface.

The operating software

It would have been nice if Reuter Elektronik had provided its own operating software for the RSR200B. For a device in the $1,000 class, this would have been desirable. The manufacturer relies on existing freeware programs that allow ExtIO.dll connection, primarily HDSDR. There are other programs such as SoDiRa and SDRSharper. SoDiRa is too complicated and has program windows that are too small for modern high-resolution monitors. SDRSharper is an SDR# clone that is not very stable and crashes at higher bandwidths. However, it is perfectly usable for small bandwidths. Currently, HDSDR remains the only stable option.

The control center for the RSR200B is the aforementioned ExtIO with the designation ExtIO_RSR200B2xx.dll. The program window is named “RSR200 Control.” This program connects the RSR200B to HDSDR. It offers many functions that HDSDR does not have integrated.

The RSR200 Control consists of two windows. The blue window contains the attenuation setting, antenna control, switchover to VHF operation, and the displays for GPS frequency correction, device temperature, and USB3 data flow display in MS/s. When activated, the “on top” function keeps the RSR200 Control always in the foreground.

The green window contains advanced functions such as switching operating modes (diversity, etc.), LO tune frequency, ADC clock rates, sampling rate decimation, IP address for LAN operation, firmware update button, and an error counter.

The operating modes

Parallel
The 16-bit data streams from the two ADCs are combined into a 17-bit data stream. This results in an increase in SNR of approx. 2dB. Channel 2 must be switched to signal input “CH1” for this. When switched to “HF2,” both data streams are also added together. However, an improvement in the SNR can only be achieved if “HF1” or ‘VHF’ and “HF2” receive exactly the same signal.

Diversity
The data stream from channel 2 is added to data stream 1 with variable amplitude and phase. If different signals are fed to the two inputs HF1 and HF2, certain signals can be amplified or attenuated by interference. The “Mix Channel 2” window can be opened to adjust the amplitude and phase.

Use the mouse to roughly find the appropriate position on the blue field. Using the numerical displays on the right, fine adjustments can be made using the mouse wheel or the buttons with the previously selected resolution. Antenna diversity largely corresponds to the signal phasing enabled by the Timewave ANC-4 device.

Seriell Up/Low
Serial addition: Channel 1 is interleaved with channel 2 with a shift of ½ clock period. The combined data stream is filtered at double the clock frequency. This corresponds to a virtual doubling of the ADC clock frequency. It is possible to select whether the upper (“Serial Up”) or lower (“Serial Low”) sideband of the resulting spectrum is further processed. The result is an increase in the SNR corresponding to the parallel addition and an attenuation of unwanted aliasing signals corresponding to the selected sideband. The practically achievable attenuation is approximately 30 dB.

Separate
Separate processing of data from channel 1 and channel 2. Both channels operate completely independently of each other (effectively two devices in one). Their signals can be fed to different interfaces for transmission to one or two PCs.

Operation via USB3 and/or LAN

The RSR200B is normally operated via the USB3 interface. This provides a maximum transfer rate of 5Gbit/s. The LAN interface transfers a maximum of 1000Mbit/s. This means that full broadband operation is not possible via LAN. The RSR200B can deliver data streams to both interfaces simultaneously. However, this is only possible with special evaluation software, which was not available at the time of testing. LAN would be interesting for remote operation. But again, no suitable software was available for this.

Installation of HDSDR and drivers

The installation of HDSDR works smoothly and should be easy for any user to accomplish. Things get tricky when installing the driver for the RSR200B. This requires in-depth knowledge of Windows. In addition, there are two driver versions available for the FTDI USB chip. There are two different drivers for older and newer PCs. But how do you know what is old and what is new? A PC older than 5 years can be considered “old.” For such a computer, you should try the old USB driver.

During installation, I chose the wrong driver and, of course, it didn't work. I kept getting an error message. After consulting with Reuter Elektronik, it worked. My i7 computer is significantly older than 5 years!

The driver for older PCs is called: FTDI_USB.
The driver for newer PCs is called: FTDI3xxWU.

I recommend reading the operating instructions carefully!

Firmware update for the RSR200B

The firmware update worked well, but there is one thing to keep in mind. There are usually two files that need to be updated: the firmware (.Bit) of the RSR200B and the RSR200 Control (.dll), which can be identified as ExtIO_RSR200B2xx.dll. Start the RSR200B with the ExtIO_RSR200B2xx.dll to be replaced and open the update window via the Update button in the green window area. Then select the new RSR200B2xx.Bit and start the update. This can take up to 5 minutes. When the update is complete, switch off the RSR200B for a few seconds. During this time, copy the new ExtIO_RSR200B2xx.dll and FTD3XX.dll files to the HDSDR directory. Then start the RSR200B. Check whether the firmware number matches the ExtIO.DLL.

Working with the RSR200B

First, you have to get used to HDSDR. I use a 34" high-resolution monitor, on which the sliders for spectrum, waterfall, etc. in HDSDR are displayed very small. This means you have to be very precise with the mouse. But after a while, you get used to it. You also have to mentally sort through and understand the many functions offered by RSR200 Control. This is because there are functions and operating modes that the average person is not familiar with and does not understand right away. Only advanced users, such as radio amateurs or professionals who are well versed in SDR technology, can interpret them correctly.

I mainly dealt with the operating modes that were relevant to me: parallel and diversity. The other operating modes were either incomprehensible to me or unusable due to a lack of suitable software.

The reception

As a comparison receiver, I used the Winradio G33DDC Excalibur Pro, which I still consider to be one of the best SDRs. There is also an Extio.dll for this receiver that works well with HDSDR.

To create identical conditions, the HDSDR S-meter had to be calibrated so that both competitors displayed a realistic signal level. For this, I used a signal generator and calibrated both to -73dBm (S9). Volume and threshold were also set to the same values.

The following antennas were used:
-- Datong AD370 horizontal active dipole
-- NTi Megadipol MD300DX vertical active dipole
-- Magnetic cross loop with RLA4/E amplifier
-- Magnetic loop with Wellgood V4 amplifier
-- CB 5/8 lambda antenna 6.20m

I received the RSR200B at the beginning of March 2025. Since then, I have been working with the device almost daily and have been able to contribute a few improvements to the RSR200 Control. Reuter Elektronik was very user-friendly and implemented the ideas and suggestions in a very short time.
The reception was impressive right from the start! Around noon, the alpha signals at the lowest frequency of 11.9 kHz were clear and had less noise than with the G33DDC.
No boredom on longwave! The usual suspects on 153 kHz, 198 kHz, etc. could be received in identical quality. Iceland could also be heard on 207 kHz, but unfortunately only in very poor quality. Constant thunderstorm interference made it impossible to listen for long.

As every night, there is a lot going on on medium wave. Numerous stations, often broadcasting on the same frequency, interfere with each other. A real jumble of stations. The perfect scenario for trying out diversity reception. To be able to use diversity, the antennas should ideally be at least one wavelength apart from each other in order to achieve some diversity gain. Unfortunately, very few of us have that much space available in our front yards. For diversity reception on medium wave, the antennas would have to be at least 160m apart. But with a little patience and luck, it also works if the antennas are only a few meters apart. With SDRSharper and an early version of RSR200 Control, I managed to separate two stations on the same frequency. After a bit of experimentation, I was able to separate “Radio Studio X” from Italy and “Radio Payam” from Iran quite well. You can hear this very clearly in the YouTube video below. This was not possible with the G33DDC because it does not support diversity.

Otherwise, reception performance on medium wave was excellent. No intermodulation was detected.

Click on the image to watch the video on YouTube.

The reception results on shortwave can be summed up quickly: excellent! Everything that could be received with the G33DDC could also be received with the RSR200B. Whether radio broadcasts, amateur radio, utility, etc., everything worked very well and was in no way inferior to the G33DDC. Often, reception of weak stations was slightly better with the RSR200B because it had less band noise. This was true in virtually all reception situations. This is probably due to the RSR200B's more modern and faster ADC. In the YouTube video below, reception of Wiluna Maritime Radio Australia.

Click on the image to watch the video on YouTube.

Click on the image to watch the video on YouTube.

Click on the image to enlarge.

FM reception

The RSR200B can receive frequencies up to 150 MHz. It has a separate “VHF” antenna connection for this purpose.
I did not test this reception range in detail because the RSR200B requires additional external hardware to receive the VHF range cleanly and without intermodulation and crossovers. The RSR200B lacks the bandpass filters and high-pass filters that are absolutely necessary for the various frequency ranges below “VHF.”
-- FM radio
-- Civil aviation band
-- DAB+

Without these filters, the VHF range is as wide as a barn door. In the FM range, FM stations, DAB+ stations, and aviation radio can be heard simultaneously and are also visible on the spectrum/waterfall.

Below: The FM band littered with DAB+ rollovers.

Conclusion:

The RSR200B is a top shortwave receiver that easily beats my reference receiver in terms of noise and sensitivity. It supports features such as antenna diversity, which makes hunting for hidden stations even more interesting. Not only that, but it also offers features that could make the RSR200B appealing even to professional users.
However, the RSR200B also has its downsides. First and foremost, it does not have its own operating software. The manufacturer relies entirely on freeware programs, some of which are not regularly maintained. A big and probably the only hope is that Simon Brown will integrate the RSR200B into his famous SDR Console V3.
In my opinion, the RSR200B has not been fully thought through. The SDR lacks the essential bandpass filters in the VHF range! In its original state, this range is unusable. The manufacturer has now responded to the criticism with the RAP2 preselector. However, this also means additional expenses if you want to treat yourself to the RAP2. Then there is the device design, which is immediately reminiscent of a car radio amplifier. In this price range, I would like to see a device that could be neatly integrated into the shack alongside other SDRs, rather than having cables coming in from both sides.

Nevertheless, the RSR200B offers very high-quality reception.

Posted: September 12, 2025