REUTER RDR54 Guida utente
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Author: Dipl.-Ing. R.Menn
Receiving Examples
Digital Communication
and
Measurement Receiver / Transceiver
RDR54 / 50
Version: English
First posted: 31/10/2012
Last change: 31/10/2012
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Content
Introduction Page 3
1.) AM broadcast band station Page 4
2.) AM reception with an interfering signal Page 5
3.) Reception of a shortwave station with a strong interference
in one sideband Page 6
4.) SHANNON Volmet 5505kHz with interference Page 7
5. ) Reception of an NDB and decoding the stations ID using
the waterfall diagram Page 8
6.) CW reception and decoding Page 11
7.) DRM reception “Reuter” style Page 12
8.) Reception of a weak SW station right next to a strong one Page 13
9.) Reception of a multiple challenged station, LHASA 4820kHz,
20:30 UTC Page 14
10.) Reception of weak signals close to the noise ground on 2m Page 16
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Dipl.-Ing. R.Menn
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Introduction
Congratulation! You are now in possession of the first stand-alone Software Defined Receiver (SDR) for the
consumer market. As you can see, it works without the need of an external PC or laptop.
The RDR54 and 50 are manufactured by Reuter engineering from Dessau Germany. And when "Dessau"
and "Bauhaus" mean something to you, you will understand why we have only one large knob and a small
amount of pushbuttons because they follow the Bauhaus philosophy that "less is more".
This document is intended to serve as an addition to the Operator Manual. It neither replaces it, nor can the
complexity of the RRD54 or RDR50 receiver be fully understood without reading the manual.
I was given the chance to evaluate the receiver’s fantastic possibilities and the ergonomics of its controls over a
longer period of time. I am not new to receivers of this quality: Kneisner& Döring KWZ-30, Perseus SDR, PM-
SDR and classic boat-anchors like the Collins R390A/URR and rare TELEFUNKEN E-52b “Köln” are among my
daily receivers. An ICOM 8500 was used for reference in the 2m band.
I nevertheless find that the Reuter RDR54 deserves a place in this line-up of top receivers. Its sound on AM with
the Envelope-Detector challenges the legendary sound quality of the Collins R-390A while at the same time the
endless filter bandwidth selection reminded me of a Perseus SDR. It’s incredible sensitivity on 2m made the
ICOM 8500 come second in many direct A/B comparisons.
In addition it serves as a measuring device with an accuracy of under 1dB total, offers more FM IF filter choices
than the best FM tuners ever made and (if that wouldn’t be enough) it is lightweight, compact and a joy to
operate.
Its raw sensitivity and ultra-low noise pushes the technical limits of reception to the absolute thresholds of
physics, e.g. the antenna noise in bands like FM and 2m.
Operating this receivers is different, sure. But after a short while, you will see that you will be much faster than
with other receivers of the classic multi-knob arrangements.
At this point, I would like to thank Mr. Burkhard Reuter for letting me evaluate this fine instrument.
It clearly follows the tradition of excellence in the field of receivers “Made in Germany”.
Saarbrücken, October 2012
Dipl.-Ing. R.Menn
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1.) AM broadcast band station
The display settings are chosen so that the signal can be seen well and an optimal listening experience can be
guaranteed.
Demodulator: AM-E(nvelope), 10 kHz Bandwidth, AGC limit –50 dBm (medium strong station)
The station was received using a loop antenna, a good choice for this band. The next image shows the same
station at the same time using a small active antenna, the SONY AN-1. As you can see, the signal/noise ratio is
less good and the modulation of the signal is weaker at the same time - > no optimal reception possible!
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2.) AM reception with an interfering signal
In the upper part of the spectrum you see a dominant “whistler”, a typical small interference signal which
will be heard as a loud constant tone.
Using the sharp edged Notch Filter, we can blank out the unwanted signal without losing too much information
of the passband. 200 Hz is a good width for such a notch. With the position control window “Position”, it can be
placed precisely around the interfering signal.
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3.) Reception of a shortwave station with a strong interference in one sideband
Shown here is the signal of Radio Rebelde Cuba, 5025 kHz, as it can be received in the early morning hours in
Europe. The lower sideband has a relatively wide interference which we can eliminate in a couple of ways.
First, we can use the SYNC-mode and simply chose the Upper Side Band, thus engage SUSB mode (trivial, not
shown). For a notch filter operation, this interference would be too wide, too much information would be cut out.
A more elegant method would be using the Passband Shift “PBT / Shift” as seen in the screenshot. Please note
that the bandwidth should be narrowed at the same time otherwise the audio gets too bright.
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Dipl.-Ing. R.Menn
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4.) SHANNON Volmet 5505kHz with interference
Intentionally, the RDR54 was set to 10,000 Hz audio bandwidth. As you can see, the signal is displayed quite
compressed, but the interference “hump” can be seen well. In this setting, the audio of the VOLMET is
completely dominated by the interference.
Using the RDR’s options, the reception can be optimized by changing the bandwidth to 3400 Hz, thus cutting
out the interference. A mild Denoising (DNR=4) helps the intelligibility of the signal. In a case like this, it is
recommended to change the spectrum display resolution to 640/display unit.
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5.) Reception of an NDB and decoding the stations ID using the waterfall diagram
In Europe, you can receive a lot of NDBs (=non directional beacons) in the upper LW band. A local station
broadcasts on 343 kHz.
Set the display resolution from 1,280 to 320 to visualize the signal better. Now the two sidebands can be seen
clearly.
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Switching to the waterfall display shows the spectrum as follows. The CW type sidebands can be seen, but the
coloring is quite distracting.
We now shift the color table so that the signal can be interpreted better (+62). It’s still the same signal, but we
“desensitized” the receiver by shifting the color table so that only the peak signals are coded in a color and the
noise stays in black.
Further shifting the color table (+79) lets now the waterfall display the dash and dots quite clearly. Any other
signal other than the peaks are suppressed.
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The station ID is ... -... ... -... ... -... or “SB” “SB” “SB”.
6.) CW reception and decoding
For the CW signal (which is usually very weak) a combination of some of the RDR54’s unique features can be
used to make the signal more intelligible. First, we use one of the highest display resolutions (160 or 320
pixel/unit), then shrink the bandwidth to a super narrow 320 Hz or even smaller. Afterwards we lift the RF
threshold OVER the noise floor of the signal (here –115 dBm).
Questo manuale è adatto per i seguenti modelli
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