The Himalaya DRM 2009 is a multistandard receiver for
AM and DRM on Long-, Medium- and Short-Wave, FM, DAB in Band III and
L-Band. It uses the Radioscape module RS500.This report is mainly based on
the practical usage of the receiver.
The size of the DRM 2009 is 27x12.5x6 cm. Some
significant features from the front include the large display, the two
loudspeakers and the "Multi Function Button/MFB". The case is well shaped
and the foldable handle is very solid compared to other receivers.
The DRM 2009 has the following external connections: DC
Input (7V, 0.7 A) Headphone output, digital audio output, USB Port (Type
Mini-B 5-polig), SD Card and an external Antenna input.
The DRM 2009 works also with 4 baby batteries. After
information of the manufacturer a minimum of 3 hours of operation is
possible. A test with an accumulator was also successful.
Switching ON
After the first switch on the receiver scans
automatically in all modes and bands. This takes some minutes depending on
the amount of stations being found. In the DRM mode only those frequencies
are scanned which have been known and stored in the factory.
The meaning of such scanning is only partly
understandable. The stations found are only a small portion of stations
exist in the bands. The five stations found after scanning in the analogue
AM bands represent only a fraction of those stations found when tuning
manually.
The Himalaya DRM 2009 is mainly
operated by the Multi Function Button/MFB which can be turned and pressed.
Programs can be activated, menus selected and all settings be done. The
operation is intuitive and well supported by the menus. To move back in
the menu only BACK has to be pushed.
All other push buttons are well
identified and don't need an explanation here. One or the other
characteristic will be explained in the following text.
On the top left hand side of the
display the signal strength his indicated, unfortunately with very small
icons. Five icons indicate best reception quality.
The symbol of the used antenna type
is indicated on the right hand side of the icons: Telescopic or internal
Ferrite Antenna. If Long- or Medium-Wave frequencies are received the
symbol of the Ferrite Antenna is displayed.
The audio issue
The audio signal of the DRM 2009 is disturbed. The degree of disturbance
of the audio signal highly depends on the situation in which the receiver
is used and has to be evaluated by each user individually.
In the typical daytime use like in
an office, when deploying DRM with loudspeakers at average volume settings,
the disturbance is not audible. In contrast, at a silent night, when
listening with low volume through the loudspeakers, the disturbance is
distracting.
Using the headphones is not recommended as the audio disturbance is much
more noticeable.
The disturbance is different in each
reception mode. When DRM is received, a buzz is audible, modulated in the
display refresh rate. DAB and FM reception are disturbed by a whistling
noise. This whistle is less annoying in AM reception mode. It is stronger
in the right hand loudspeaker than in the left hand one and, in FM mode,
slightly audible on the right hand loudspeaker, even when the headphone is
plugged in and the loudspeakers should be silent. This could be an
indication of interference in the AF part.
All disturbances are not present in the digital audio output signal, in
this case the reception is flawless.
AM Reception
By
pushing the MODE button different reception modes can be selected one
after another. We start with the classical AM reception.The first scanning
has also found some AM stations which are displayed, only the procedure is
not known why only these stations have been selected. It is better to use
the manual tuning for AM as well as for all other modes.
To tune manually the MFB has to be pushed and kept
down for one - two seconds until the display indicates "Manual Tune". By
turning the MFB the frequency can be adjusted depending on the frequency
range. For Longwave the steps are 3 kHz, for Mediumwave 9 kHz and for
Shortwave 5 kHz. By pushing the MFB again for a short time, the frequency
tuning step can then be set to 1 kHz as a "Fine Tune" option.
It is recommended to store the favourite stations on
the ten positions for fast access.
The reception quality is in general convincing. The
Himalaya is also with the internal Ferrite Antenna sufficiently sensitive.
E.g. the reception of the Youth program of the BR on 801 kHz could be well
received South of Berlin.
But he Medium Wave is not anymore analogue only.
Station names can be displayed thanks to AMSS. This was tested with
Truckradio on 531 kHz and BBC on 648 kHz.
FM Reception
The FM reception with the Himalaya DRM 2009 is solid but not surpassing
ordinary receivers. The FM bandwidth is 200 kHz and the sensitivity is not
overwhelming good with the incorporated telescopic antenna. If an external
antenna is used the reception quality improves considerably.
The display shows the reception of 93.1 MHz with the
Telescopic antenna. The signal is noisy and a RDS reception is not
possible. In the left hand picture the RDS error rate of 75% is shown (very
unstable).
After connecting a simple indoor Dipole Antenna the FM
reception improves considerable with full RDS reception and 0% error rate.
In the FM mode the meaning of the
signal strength indication is not always clear when four bars are
indicated but the reception quality is poor and not sufficiant for
RDS-decoding. The himalaya needs a good receiving signal for perfect RDS
reception.
During the FM reception a disadvantage of the menu
operation becomes obvious: six steps are needed to change in the third
sub-menu from stereo to mono.
DAB Reception
For the DAB test the Himalaya DRM 2009 was compared with the Pure Evoke
1xt. In general it can be stated that the DAB test confirmed what other
tests have shown with receivers based on the RS500 module.
For the first DAB test both receivers were placed at
the same location and the telescopic antenna put in the same direction.
After the scanning both receivers found the same amount of DAB stations.
When receiving a DAB station the Pure starts first with
audio decoding but still interrupted. At a signal indication of 55 on the
Pure display the Himalaya starts also to decode. From signal strength 65
on the Pure display both receivers decode the DAB station without
interruption of the audio quality. It can be assumed that both receivers
are equal.
In a second test both receivers were connected to an
external antenna and the results were the same.
DRM Reception
The result at the beginning: The Himalaya was very convincing when
receiving DRM. According to our experience, it is important to note that
for the best reception quality is achieved by both using the right antenna
selection and using the manual tune.
To tune to a DRM station it is also
possible to scan in the DRM mode. As the success depends on many different
factors, it is recommended to search also for known stations. For this the
MFB has to be pushed until "Manual Tune" appears on the display. Now the
desired frequency can be tuned. As already explained for AM tuning it is
recommended that the most favoured frequencies are stored under the ten
positions.
When receiving DRM the Himalaya
shows all the possibilities. The audio signal is missing some lower
frequencies because of the loudspeakers but with sufficient loudness.
The associated data such as text are displayed as
floating text under the station name. If the EPG button is pressed and
hold for ca. 3 seconds the floating text will be shown in a block.
DRM Reception Test
To evaluate the reception quality under realistic and repeatable
conditions the Himalaya DRM 2009 was compared with different receivers
which were connected to different antennas.
DRM Test with Internal Ferrite Antenna
The test of the internal Ferrite Antenna was done by
comparing the Himalaya DRM 2009 with a DRM modified SONY 7600 G and PC
decoding. Receiving the quasi local station DLF on 855 kHz and the far
away station BBC 1296 kHz both receivers showed stable and equal results.
Left the Display of the
Himalaya, right the Screenshot at the PC. Both receivers are tuned to 1296
kHz.
A real challenge fort his antenna
configuration is the reception of WDR 1593 kHz from Langenberg, some 460
km away. Whereas the reception with the SONY is not stable shows the
Himalaya a constant decoding of the SDC and the station label. Audio could
not be decoded over this long distance.
DRM Test with Telescopic Antenna
Also for this test the comparison was done with the
SONY 7600G. The reception of DW on 3995 kHz was a bit better, maybe
because of the remarkable longer antenna.
When receiving RTL on 5990 kHz and 6095 kHz as well
BR on 6085 kHz both receivers showed identical results. This was
satisfying as all DRM frequencies could be received.
External Antenna (Magnetic Loop)
The first test with an external antenna was done
with a self-made Magnetic Loop antenna. As receiver a very good SDR drb300
receiver was used.
For the Medium Wave comparison the transmitter WDR
Langenberg on 1593 kHz was used. Reception over 460 km distance is for
both receivers a big challenge. A continuous uninterrupted reception would
be South of Berlin only possible with a huge effort.
But surprise: Whereas the receiver drb30 decoded the
audio only with long pauses was the period with the Himalaya 2009 much
longer with less interruptions. This confirms an experience which was made
with the Truckbox that receivers with the RS500 module are decoding audio
in critical reception conditions faster and more reliable. Although the
reception signal arrives in good quality at the PC, the decoding software
not so good.
The RTL frequencies 5990 kHz and 6095 kHz as well as B5
on 6085 kHz were tested with a Magnetic Loop Antenna. The results of the
drb30 and Himalaya DRM 2009 are in general equal.
When receiving Deutsche Welle on
7275 kHz the combination of drb30 with Dream was advantageous. The audio
signal was much longer decoded than with the Himalaya. Obviously the
excellent sensitivity of the drb30 is the reason.
First (Pleasant) Surprise with DRM Reception
A Medium Wave scan during evening hours showed
suddenly the station name "SWR>>cont.ra<<. And really the SWR station on
1485 could be received with its station name over a distance of some 600
km.
The pictures show clearly the station name, date, time
and SNR value of 9 dB. Compared with the receiver drb30 and a magnetic
loop antenna that gave identical values, it proves the Ferrite antenna and
the DRM2009 receiver are both very well done.
Second (Pleasant) Surprise with DRM Reception
The external antenna was disconnected during the
reception of the BBC on 1296 kHz. The signal strength with the telescopic
antenna was not sufficient but after ten seconds the Himalaya indicated
that it is scanning for alternative frequencies and found the BBC on FM
90.20 MHz. It shows the success of AFS implementation.
With this AFS experience, it was tested on another
frequency. The receiver switched from Deutschlandfunk with DRM on 855 kHz
to FM on 97.7 MHz after 10 seconds searching.
AFS functions also with DAB (Inforadio on 8C) switched to FM (Inforadio on
93.1 MHz) or even in DRM mode only with the BBC on 1296 kHz switching to
BBC on 5875 kHz.
Playlist Modus
In the play list mode data from the SDCard can be
played. This worked very well even with mp3 files encoded with different
bit rates.
But this mode is also very good for a completely
different usage: as log book for the DRM reception. The audio recording in
DRM mode can be started at any time by just pressing the record button.
The recorded audio file on the SDCard contains also the station name, date
and time. A nice registration of reception results.
The recording of content as well as the time
shifting both worked perfectly.
Interesting
If "Setting" is selected in the menu and the MFB is
held down, the "Engineering Menu" appears. Here a lot of information and
settings are possible.
But attention! Some functions are not documented and
could reduce the functionality of the Himalaya 2009. Everybody is
responsible for using these functions!
Very interesting ist he
information about each transmission mode. This is achieved via the "Stack
Status".
Whereas for the AM reception only the frequency is
shown are for the DRM reception many information displayed.
Also in the Engineering mode the usage of the internal
Ferrite Antenna can be changed. In the setting by the manufacturer the
Ferrite Antenna is used for all frequencies up to 1710 kHz. If this
function is disabled in engineering menu under "Antenna Setup" the
reception via an external antenna is also possible for lower frequencies.
If the Himalaya DRM 2009 is
connected with a PC via the USB port, the SDCard can be accessed. In this
case the Himalaya works like a SDCard reader. It is not known if this
interface gives also access to the firmware.
Firmware update is possible
with the SDCard. For this the SDCard with the Firmware will be plugged in
the slot. Now the "Update display" appears and the steps for updating can
be followed.
Proposals for
Improvement
If the power plug is taken
out during operation and provided batteries are in place the receiver
starts again to switch on. This does also happen the other way round.
Plugging the power supply in the receiver during battery operation the
reception is interrupted and the receiver starts again. This should be
avoided in one of the next receiver generation for always uninterrupted
operation.
Already with the next firmware upgrade the indication
of reception quality in DRM and DAB mode should be increased. The SNR
value for DRM reception and the quality value for DAB reception should be
permanently or at least if desired indicated. The values are available as
can be seen under the Stack Status in the engineering menu.
Also with software a direct switching to the same
frequency between DRM and AM should be possible. The Truckbox shows that
this is possible. With this feature the listener has the possibility to
check in AM mode if the reception on DRM does not work and can locate a
local noise source.
A third improvement could be the permanent indication
of the reception mode.
If possible a fourth
modification could be done by putting the switching between Ferrite and
Telescopic Antenna directly in the Setting Menu.
The antenna input socket
should be placed at a later version when the hardware is changed on the
side of the box. The present solution is not very good if the receiver is
used in a tilted position as the load of the receiver could damage the
external antenna plug.