Malahit DSP2 Portable SDR Receiver
It's not like I don't have enough radios but I just
had to try
this one. I first stumbled across it on eBay, where there are numerous
clones available (also on Amazon I'm told). Then I did some research and found out that it had
been designed and first built by a group of ham engineers in Russia.
The Russian version was more expensive and hard to order, but had two
bonuses: the firmware was fully functional and the hardware quality is
top notch.
As you can see it is a fully functional SDR recever
with an
amazing display which is also a touch screen. It covers 10 kHz to 380
MHz and 400 MHz to 2 GHz. There are two pushbutton rotary encoders. The
SMA antenna port is on the top, and the power button and headphone jack
is on the right side. There is also a USB socket and an LED on the same
side lower down. The USB port is a USB mini A type, the same as was
used by most mobile devices for years before USB-C became standard, so my years-old cellphone cable works. It
uses one 18650 lithium rechargeable cell* and has a built-in charger,
which uses the LED to indicate the status during charging.
I
odered my unit in March 2021. At that time the original (DSP1) version
was
being made. Months went by and finally in July I was informed I was
being shipped the DSP2 version. The shipment was tracked and my radio
made its way from Ekaterinburg to Moscow and finally New York and
Canada in a few weeks.
I really like this radio although it has
a few quirks. I may add more of a review when I have spent more time
using it. It was a bit frustrating finding documentation since most
information available was for the original version and/or in
Russian. There are a few web sites and youtube videos if you look for
them. (Here is a good overview.) Meantime, the best place for information on the Malahit is
this groups.io page: https://groups.io/g/malahit
. A DSP1/DSP2 user guide in English has been released. There's much
more to be said about this radio, it has tons of features to discover.
(There is also a Telegram group dedicated to the Malahit.) A good place
to find documentation and firmware is here.
And the Malahit team now have a decent web page here, with
ordering information.
Just
a note on the firmware. The DSP2 came with vesion 2.0 but in the
following months there were several updates. The firmware can be
updated but it is a little more complicated than for some devices. You
need the STM microprocessor programming program on your computer. Links
are provided for downloading it. It is not as straightforward to use as
it could be but
there are instructions available. Firmware update is done via the USB
cable. Basically you put the radio in program mode (called DFU), tell
the STM program to connect to a USB device, choose the firmware
file to use, and tell it to download. I have done it
successfully several times so far. If you've done everything right the
radio boots up with the new firmware.
I
found that with the included whip antenna, the reception on MW was very
poor. Especially in the range 800 to 1200 kHz, I couldn't pick
up anything. A post on groups.io by KD9NXV
addressed this problem: the inductor L7 that supplies the bias-T power
to the
antenna port. At first I decided to leave it alone in case I got an
active antenna. However after finding that the available antennas were
too expensive for me I decided to remove L7 as instructed. The improvement on
MW was dramatic and I'm glad I did it. (When using the whip make sure
the antenna is set to Hi-Z.)
After using this radio for a few months I have to say that it is the
best overall portable receiver that I have used. It goes from SW to VHF/UHF
quickly and easily. It is very sensitive and the noise reducer is
excellent. (My RSP1A won't receive anything weak on VHF unless you fuss
with the LNA and gain settings.) The Malahit just works. There are lots
of features you can play with if you like, I ignore most of them and
just enjoy using the radio.
I found that I wanted a holder for the radio to make it easier to use. There was one available here,
but there were a few problems ... It was expensive and payment is
difficult. (Because of events in 2022 it may not even be available
anymore.) Then I saw a youtube video where a tablet holder was being
used. I couldn't find the holder he used, but there were numerous
others available. I found one for C$10 and it works just fine. You just
have to make sure the holder does not cover up the speaker.
* The 18650 I ordered turned out to have
a protection circuit added to the top of the cell. I suppose this could
be useful but my cell was too long and would not fit in the Malahit's
holder. 18650 is not a standard type in my shack and I didn't have
another one to try. Also, 18650s are expensive here and hard to get. So
I cut around the top of the cell and removed the protection circuit.
Then it fit fine and has been working OK since. Presumably the radio
has the necessary charge circuit to match the battery. (FYI there is a
mod available for installing a 2nd cell to extend the run time.)
In 2023, the DSP2 model is replaced with a DSP3 model.
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