RDR55 | K&M Burkhard Reuter
The RDR55 is a modular receiver - transceiver with 7'' touch display. It can be adapted to many operating conditions, in the range of 1 KHz up to VHF, thanks to its exchangeable modules. The full metal aluminum housing enables extensive shielding measures. Ideated in Germany.
Reference market : ham-radio / professional
0.0010 ~ 30.0000 MHz
50.0000 ~ 71.0000 MHz 
87.5000 ~ 108.0000 MHz 
136.0000 ~ 154.0000 MHz 
1.8100 ~ 2.0000 MHz
3.5000 ~ 3.8000 MHz
7.0000 ~ 7.2000 MHz
10.1000 ~ 10.1500 MHz
14.0000 ~ 14.3500 MHz
18.0680 ~ 18.1680 MHz
21.0000 ~ 21.4500 MHz
24.8900 ~ 24.9900 MHz
28.0000 ~ 29.7000 MHz
|Modulation mode||CW / LSB / USB / AM / AM-S / DSB / FM / WFM|
0.5 Hz min
User-defined 0.5 Hz ~ 999,9995 kHz
|MDS (Minimum Detectable Signal)||
-136 dBm (0~54 MHz, BW=20Hz, preamp ON)
-150 dBm (144 MHz, BW=20Hz)
2.5 Hz ~ 20 KHz (user-defined)
50 / 80 / 120 / 240 kHz (for WFM)
|A/D conversion||Freq.||83.8 Msps|
|Res.||4 x 16 Bit|
|Sampling out||163.84 Ksps|
|RF preamplifier||15 dB (0~54 MHz)|
|RF attenuator||20 dB|
|IF-filter ultimate attenuation||130 dB|
|Clipping Level||0 dBm|
|Notch attenuation (Manual)||130 dB max attenuation|
|Noise blanker (NB)||
15 adjustable response thresholds
0~99ms adjustable blanking time
|Noise reduction attenuation (NR)||10 adjustable levels|
0.1~99.5 dB/s attack rate
0~99.5s hold time
|Frequency stability||± 1ppm after 10 minute of power-on|
|Audio response||20 Hz ~ 15000 kHz (user-defined)|
|Memory||63 for setting / undo function|
|Display||7-inch TFT, 800 x 480 pixels|
SMB 50Ω connector (0~30 MHz)
SMB 50Ω connector (50~71 MHz)
SMB 50Ω connector (87.5~108 MHz)
SMB 50Ω connector (136~154 MHz)
SMB 50Ω connector (filter-less input)
|Power supply||110~230 VAC|
25 VA max
1 VA standby
2 W (speaker)
13 mW (headphone)
|Audio output||Jack 3.5 mm headphone|
Jack 3.5 mm (S/PDIF digital audio) 
SMB (reference clock)
|Mechanical and environmental data :|
|Operating temperature||from 0°C to +50°C|
|Dimensions||290 (W) x 125 (H) x 245 (D) mm with folded-up feet|
 The measuring and communications receiver RDR55 can be upgraded with the RPA5C module to be used as a transceiver for the amateur bands
The RDR55 is a modular receiver (also transceiver with the RPA5C module) controlled through the touch screen. It can be adapted to many operating conditions thanks to its exchangeable modules, the full metal aluminum housing enables extensive shielding too. The main RAD18E front-end module provides four 16-bit ADC chips for an 18-bit RF data stream. From 1 kHz up to 30 MHz a continuous reception is possible (31 MHz low-pass filter), the 6 meter band of 50~54 MHz is filtered with an LC filter, 3 meter FM and extended 2 meter amateur radio band (up to 150 MHz without attenuation, to 154 MHz with increasing attenuation) are filtered with multi-pole SAW filters. This module achieves very high sensitivity and intermodulation immunity. Signals with double sideband modulation, single sideband, with or without a carrier, keyed signals (CW) as well as FM signals can be received. The receiver bandwidth and gain are adjustable within a wide range, either with a manual gain or via the configurable automatic gain control.
The RDR55 is based on digital signal processing representing an enhanced Software Defined Radio (SDR) approach. After digitization of the received signal a conversion is done from the time domain into the frequency domain using fast proprietary algorithms (no FFT). The result is a spectrum of 163.84 kHz width cut-out with a selectable frequency resolution. Additional signal processing is performed then in the frequency domain, except for FM.
The receiver architecture consists of a base mainframe unit with plug-in modules which are easily replaceable. All major software components are upgradeable via the USB interface, as well as all the hardware configurations used in the programmable circuits (FPGA). Connection to an Ethernet network is possible using an optional module.
Other features :
Dynamic range of signal processing: at least 36 bit linear range, 18~32 bit audio and dB-converted signals range.
DNR Noise reduction system: with 2 algorithms. IQ process and magnitude method.
Level of accuracy: < 1 dB without filter, 1~2 dB with automatic RF Filter.
Gain control range: 140 dB in 0.5 dB steps, manual and automatic.
Resolution time-frequency conversion: 2.5~320 Hz in 8 steps.
Spectral resolution on x-axis (frequency): from 2.5 Hz min.
Spectral resolution on y-axis (level): from 0.05 to 0.5 dB/line, dBuV or dBm scale, 2 markers, S-level display with 0.1S resolution.
Video spectral filters: OFF, arithmetic average, quasi-peak, maximum hold at 0~9.9s, or infinite measurement time.
Antenna high-pass filter: into the signal path of "ANT1" a coupling capacitor to increase the lower limit frequency to about 75 kHz can be switched on.
External synchronization: about ±100 ppm at 0 dBm external oscillator level.
RDR55 price :
We have collected for your convenience the RDR55 K&M sales prices and their trend over time. Of course offers, accessories, warranty terms and conditions can lead to different figures.
Order designation RDR55E1 with module RAD18E and RDR35D.
Order designation RDR55E2 with module RAD17E and RDR35D.
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