At the amateur radio
show Hamradio 2016 in Friedrichshafen, Reuter Elektronik showed for
the first time a prototype of a portable SDR with full range
spectrum "RDR51-Pocket". From the outside, the small device
looked promising. Solid housing, cleanly processed and fast display.
This small device attracted many visitors. As a result, Burkhard
Reuter decided to build the "Pocket" and offer it in a small series.
Burkhard Reuter, the owner of Reuter Elektronik, had set a high goal.
A portable receiver with state-of-the-art SDR technology, which
should also meet high demands. At the beginning of 2017, the first
devices were delivered.
Actually, I should have been one of the first to receive a Reuter
Pocket for testing. But procurement problems with the components and
unexpectedly many pre-orders pushed the lending of the Pocket very
far back. Mr. Reuter contacted me in early November 2017, he could
finally provide me with a fully equipped pocket. It was not a week,
the device was there.
After opening the neutral box, the supplied accessories come to the
fore. Everything well packed in bubble wrap. Then a black protective
bag is fished out of the box. Inside is the Pocket, additionally
packed in a plastic bag.
The trained eye immediately recognizes the perfect workmanship! The
case of the Pocket is made of an aluminum / magnesium alloy. This
has the advantage that the interference of the installed electronics
is significantly reduced and the mechanical stability is increased.
Reuter Elektronik has already shown with other recipients that
high-quality workmanship and the selection of the best materials are
part of the company philosophy.
The operating concept is like the big brother RDR55. All settings
are made via the 4.3 inch touch screen and the scroll wheel. In the
middle of the scroll wheel is the on / off button. If you press this
for three seconds, the device turns on. After a short start-up phase,
the user interface appears. This is largely like that of the
tabletop devices. The Pocket can also be used as an amateur radio if
you order it with the appropriate module. But then you have to do
without FM and DAB +. For both together there is too little space in
the small housing.
The Pocket works on the same principle, the frequency-based way of
working, like its big brothers. This operation has the advantage
that the audio is derived directly from the visible spectrum. This
means that the audio and spectrum are absolutely synchronous, ie
real-time! Time-based SDRs, such as Winradio, Perseus, etc., always
have some delay between the audio and the spectrum. A good
description of the frequency-based working method can be found here
Thanks to its compact dimensions and built-in batteries, the Pocket
becomes a portable device. He can be easily transported in the
jacket pocket. Due to its design principle, the Pocket has no
built-in receiving antenna. Except a WLAN and Bluetooth antenna,
which is integrated in the appropriate modules. This means that for
portable operation you should have at least one telescopic antenna
with SMA connection.
The main features of the Pocket
-- Frequency range : 1KHz - 30 MHz, 50 -
71 MHz, 87 MHz - 110 MHz, 130 - 156 MHz,
174 - 240 MHz (DAB + reception only)
-- Bandwidth filter: 10Hz - 20KHz freely
adjustable in 40Hz steps. Depending on
the audio resolution.
-- Frequency - based modes: Sync - DSB -
LSB - USB - EUSB - SBCW - CW
-- Time based modes: AM-E - FMN - FMW -
USBQ - LSBQ - DIGI - DSBQ
-- Tuning range: arbitrarily adjustable
from 0.5Hz - 999.999.5KHz / direct
selection of preprogrammed step sizes
-- Visibility of the spectrum: Smallest
viewing width: 6.2KHz, widest viewing
width: 52MHz (option)
-- FM mono / stereo with wide function
-- FM filters: 38KHz-S, 50KHz-S,
80KHz-S, 80KHz-HQ,, 120KHz-S, 120KHz-HQ,
240KHz-HQ, 300KHz-HQ (S = Steep filter
edges, HQ = Flatter filter edges for
optimum listening pleasure )
-- DAB + reception in mono or stereo
-- 256 memories
-- Passband tuning
-- AutoNotch & manually adjustable notch
-- AGC: increase and hold time
-- 2x 14bit ADC model B2 (review sample)
- optional 2x 16bit on model C2
-- Real-time spectrum and waterfall
-- Fast and very bright TFT- display
with 4.3 "(109 mm) diagonal, WVGA 800 x
480 pixel resolution
-- GPS module for frequency calibration
and information on altitude, coordinates
and time in UTC.
-- WLAN module for wireless firmware
updates & screenshot functions
-- Bluetooth module for connecting
wireless speakers or headphones
-- Bandpass filter for LMK (1-10MHz,
10-30MHz) or bypass
-- Bandpass filter for the 6m range (50
-- FM bandpass filter (87 - 110MHz)
-- 2m bandpass filter (130 - 156MHz)
-- Bandpass filter for the DAB + range
(174 - 240MHz)
-- 8 GB flash memory for audio
-- SMA connections for LMK, FM & DAB +
reception, as well as WLAN & GPS
-- Lemo socket for the power supply
-- 3.5mm jack sockets for headphones /
speakers, microphone & Morse key (with
-- 2 built-in speakers for stereo output
-- 2 batteries with 2600mAh
-- Dimensions: 158 mm x 110 mm x 30 mm (WxHxD)
-- Weight: 700g
-- Transport bag
-- Adapter from SMA to BNC (Pigtail)
-- GPS antenna with 3m cable
-- Charging and power supply cable with
Lemo and banana plugs
-- CD with software
Put the Pocket in working position
To get the Pocket into a comfortable working position, there are
three options. The first installation aid is from Reuter Elektronik
<Link>. This is a bent acrylic glass. Just put the pocket on the short thigh.
The second variant comes from the 3D printer of a resourceful radio
amateur. The two feet are simply pushed over the shell of the pocket.
These stalls are the smallest and are very suitable for portable use.
These fit well into the bag pocket. The 3D file can be downloaded
The third variant is a universal positioning aid "Modell München"
for many portable devices. It is available at Wellenjagd.de. <Link>
A little tip at the point: With the device stand of Reuter and
Wellenjagd. I recommend to attach the pocket with Velcro to the
stand. This prevents the device from slipping off. Of course you can
also hold the device in your hand ...
Working with the
The inexperienced owner of such a high-tech device should keep the
instructions ready. Because a few functions must first be understood
correctly in order to fully exploit the performance of the Pocket.
Of course you can easily operate the Pocket in the default setting.
If you tap on the button Menu, a dialog opens with submenus. If you
then tap on the button Setup, you get to the most common settings of
the Pocket. Here you can set a variety of function parameters.
Special attention should be paid to the function "Impedance
0-71MHz". Here you can set 0Ohm, 50Ohm and ~~. Default value is
50ohm, for eg active antennas and dipoles. 0Ohm is intended for
small antennas, eg a telescopic antenna for the road. The infinite
setting ~~ is intended for low frequencies in conjunction with a
short antenna, because in this setting the signal is amplified by
14dB. The other special setting is the "Resolution Audio (Hz /
Bin)". This setting affects the sound and setting options of the
spectrum-based demodulators. It determines the audio resolution
associated with the adjustable bandwidth. 3 levels are possible. At
10Hz resolution the maximum adjustable bandwidth is 5.1KHz. 20Hz
results in 10.2KHz and 40Hz results in 20.4KHz bandwidth. The latter
should only be used if you want to listen to strong broadband
channels over 11KHz. Default value is 20Hz / Bin. This is sufficient
in most cases. For extremely weak stations 10Hz / Bin can bring
advantages in the intelligibility. That's the finest resolution.
main discipline of the Pocket is the reception from 1KHz to 71MHz.
For this frequency range and frequency-based operation, the device
provides a variety of functions to optimize reception. One can
confidently call the variety of functions professional. Because
nothing is missing. Various functions are not available in the
time-based mode of operation. For example, the NB, DNR, Notch and
PBT. The bandwidth selection is limited. But the pocket sounds
rounder, fuller. Almost like a tube receiver. The FM band, which
includes the 2m amateur band and DAB +, is not generated by the
frequency-based method, but also by time-based methods (like
traditional SDR's). So here are also certain restrictions that are
not significant. With the HQ (High Quality) filters, which are
optional for FM broadcasting, there are eight bandwidth filters to
choose from, which are absolutely sufficient for demanding
broadcasting enjoyment. For the time-based modes AM-E, FM etc. there
are 15 bandwidth filters available. These filters are not hardware,
but DSP filters!
Due to its compact dimensions, the handling is getting used to. The
touch screen can be operated with the fingers or with a PDA stylus.
The latter is the better choice because some buttons on the display
are very small. The most obvious is of course the fast working and
very sharp spectrum. Even if you tune through the tape, no delay is
noticeable. I do not know any other SDR with such a fast spectrum.
Next comes the Icom IC-R8600.
With the PDA pen tapped on the frequency display, opens the input
and memory dialog. Times a frequency in the 49m band set in the
"Synch" mode. Immediately the station becomes audible. "Synch"
actually means AM-Synchron. This mode is the standard mode, so to
speak, if you want to hear AM station. The signal is detected and
synchronized immediately. A normal "AM" like analogue radios does
not exist here.
The very early models of the RDR devices had a slightly tinny audio.
The Pocket with the latest hardware and software, however, sounds
analog in the frequency-based mode of operation! No artifacts, no
canned sound! What usually only stands out in direct comparison, is
the very low noise of the Pocket. A real treat for the ears. For
very weak and poorly understood broadcasters, one can fall back on a
good tool. The "surround" function. Once activated, it can
significantly increase intelligibility and produce a stereo-like
If the reception is undisturbed, you can switch to the time-based
modes. AM stations can then be heard in "AM-E". The bandwidth
filters have flatter filter edges and sound rounder. The audio gets
more fullness and sounds warmer. Also for the sidebands (LSBQ & USBQ)
there are own demodulator doors.
Pocket on the way
As the name suggests Pocket, the small fits well in the jacket
pocket. To be able to listen to the radio on the go, all you need is
a telescopic antenna with an SMA connection. The Diamond SRH789 fits
very well with the Pocket. The SMA connector of this telescopic
antenna is designed in such a way that the SMA cable gland does not
release itself when turning the antenna. Because the SMA union nut
is free-spinning. Be careful when buying the SRH789! There are fakes
in which the SMA union nut is rigidly connected to the antenna. Only
the original is worth the money.
If the antenna is screwed on, you should set in the menu the input
impedance to "0Ohm", so that the full sensitivity can be used. I
took the pocket on some walks and felt it on the tooth. The
reception was largely impeccable. The feared disturbances by the
device itself, kept within limits. At a distance of about 46KHz,
peaks were seen in the spectrum. These disturbances were mainly
generated by the display. In the power management dialog there is
the function "spread spectrum" which makes it possible to smooth
these disturbances. But that is to the detriment of the background
noise. This increases a bit. The Pocket is really fun with a
powerful antenna. For example, with an active dipole. I put together
a portable set in a suitcase for portable hardcore reception. The
whole thing is set up in 5 minutes. So far from home disturbances, I
can enjoy distant and weak stations. The two built-in rechargeable
batteries last about 5 hours in headphone mode.
The audio comparisons from VLF to 30MHz
Although the Pocket is designed for portable use, it can be easily
operated on the station antennas. The usual hobby antennas he
tolerates easily. Therefore, the audio comparisons were made at home
in the Shack, which was also more convenient.
The Pocket can be tuned from 1KHz. Reception is only possible from
9KHz, because the antennas are not received so far down.
To be able to assess a device, you need a comparison device as a
reference. For this, the proven Winradio G33DDC Excalibur Pro
offered. This is one of the best SDR's, which is under 2000 € to
Below are the audio comparisons between the Reuter Pocket and the
Winradio G33DDC Excalibur Pro. To hear the differences is the use of
a headphone a must. Both devices were operated with the same
settings and were supplied with the antenna signal via the antenna
distributor of Elad ASA-62. The audio was recorded via an audio
switcher with the recording software Audacity. The shots were not
edited, just cut to the appropriate length.
Used Antennas : Datong AD370 & Crossloop-RLA4E/2
Second 0 -
10> Reuter Pocket
Second 10 - 20> Winradio G33DDC Excalibur Pro
The reception of the
alpha signals at 11.9KHz, 12.65KHz and 14.9KHz compared to the
G33DDC Excalibur Pro. Reception antenna Datong AD370.
ERTU Shamal Said
Pocket mit Surround
Radio Cultural Amauta
Pocket mit Surround
Voice of Iran
Voice of Turkey
Radio Habana Cuba
audio comparisons of long, medium and shortwave were made with the
Kreuzloop RLA4E / 2.
The reception on FM
With the Reuter Pocket you can also comfortably listen to FM radio.
It receives from 87 - 110MHz. There are eight bandwidth filters
available. With the "HQ" filters, it is also very good to enjoy
strong incoming stations almost noise-free. With the function
"Stereo Wide", the stereo base can be doubled. This gives the
already good-sounding audio even more sense of space. The RDS
decoder works quite fast and sensitive. It indicates the PI code of
the transmitter, as well as information on faulty blocks corrected
by the decoder. For FM Dxers and specialists an interesting thing!
On a Superdiskone the pocket receives acceptable to good. At times
he overrides something. This is noticeable by the red glowing
frequency display. Also in the spectrum, unwanted peaks appear. With
the attenuator can get this under control. Active antennas can not
stand the VHF receiver. It is best to treat it to a small passive
outdoor antenna or a telescopic antenna on the device itself. Then
the VHF receiver receives perfectly. If you have the antenna history
under control, even FM-DX is possible with the Pocket. With its
narrow bandwidth filters it is possible to make weak transmitters
audible between the thick brads. There are two ways to represent the
spectrum. Either normal, where you can see the stations in 100KHz
grid, or you can set it so that you can represent the MPX
(multiplex) signals. The latter only works with stations that
transmit in stereo or when switched to stereo.
DAB + reception
Besides so many features, the Pocket still offers DAB +! The Pocket
receives the DAB Band III (170 - 240MHz). This does not work the
same way as with the traditional DAB + receivers. In the tested
software version V2B8, the Pocket does not permanently store the
stations. When accessing DAB +, a search is always triggered and
lists all receivable stations in a list. This list can be moved with
the scroll wheel. To call the transmitter is simply typed on the
appropriate field. The search takes between 30 seconds and one
minute. Depending on how many stations are found. The reception
works very well. The playback is absolutely noise-free. In the
tested software version not all data packets are processed yet.
Pictures can not be displayed yet. Text, however, already. When
searching on the Superdiskone 141 channels were found. Outside with
the telescopic aerial, there were still 105 transmitters. In
addition to the station name, data of the ensemble and station
identification are also displayed.
The present device has an 8GB flash memory that can be used for
audio recordings. This takes up in 24bit resolution. A useful thing,
if you want to log very weak signals and the station has not noticed.
These can then be played.
I had the Reuter Pocket over two months in the test. He was present
at the DX-Camp in the Holzerbachtal near Solingen and was tried
there on all antennas. At home, too, I used it intensively and
compared it. Mainly with the Winradio G33DDC Excalibur Pro. The
Pocket could easily handle the hobby-usual antennas. Except the NTi
Megactiv 305 and the MiniWhip caused him some problems. These
antennas caused short-term overloading the ADC. The frequency
display occasionally turned red, but there was no audible
intermodulations or increased noise. The reception differences to
PC-based Winradio were minimal. The Winradio has a slightly lighter
rendering that made very weak signals a little bit more
understandable. The performance of the little pocket has surprised
me completely and convinced! Excellent sensitivity, very low noise,
extreme selectivity and an almost incredible flexibility in signal
processing leave nothing to be desired. Add to that the FM, DAB +
reception and the excellent workmanship. What did not work in the
test phase was the Bluetooth function. The driver was not available
The first pocket-sized portable direct sampling SDR with the
performance of a semi-professional receiver. The Reuter Pocket is an
exceptional device! This device concept is currently unique in the
As you can only say: absolute top class!