N9EWO Review :
 "Malachite-DSP"
"Original" Russian 
Standalone SDR
 
(software defined radio receiver)


  N9EWO's report of the Russian "Original" Malachite / Malahit fully standalone DSP Receiver.
Frequency coverage is 50khz to 250MHz and 400MHz to 2GHz in all popular modes.
Price at the time this report was compiled is € 179 plus shipping (approx $ 210. USD)
sold direct via the developers in Russia. Fully assembled and ready to go (kit versions are available) !
Please do NOT confuse with the Chinese "copy" versions (see text). (N9EWO Photo)


N9EWO Review :  "Malachite-DSP" "Original" Russian  Standalone Radio Receiver (software defined)

Important Notes : This report will be looking at this receiver more on the "Short Wave" HF side of the fence below 30 MHz. However will cover basic performance above HF as well.

Please DO NOT confuse this review text when compared to ANY of the Chinese "almost" copy devices. It very well may NOT (probably NOT) be valid. We have not tested any other of the Chinese devices (one test sample acquired was defective and badly designed, please see yellow block below).

For general reference : "Malachite" is the name for the hardware. "Malahit" is the firmware name used in this SDR.

Model : Radio Receiver "Malachite-DSP"

Country Of Manufacture : Russia Federation

Approx. Serial Number of Test Sample : (none was found on test sample case)
Firmware Version Tested : 1.0d

Optional Accessories Tested :
- CCRANE USB 5 Volt 900 ma Regulated Linear Power Supply [Made in Korea]
- YCSbasics 1 Meter / 3 Foot USB Cable Adapter A5575Q [USB 5 pin micro male to USB mini 5 pin female for use with CCrane Adapter above]
- 3.5 to 30 MHz External "Band Pass Filter" [Made in China]
- Homemade 20 db External Variable Attenuator

Test Antenna's :
- Short 20 foot [6 meter] indoor wire antenna
- Comet DS150S Discone Antenna (30 foot [10 meter] height)
- RF Systems MLBA-MK2 long wire (55 foot length [16.7 meter] - 24 foot [7.3 meter] height at peak)
- Comet H-422 Dipole 31 feet [9.4 meters] in length  (24 foot [7.3 meter] height) - Straight Configuration)

PRO :
- No activation code from developers required to operate with Russian version (as purchased from Russia).
- Solid Robust Anodized Aluminum Metal Cabinet.
- Wide 50 kHz to 2 Ghz Frequency Coverage with only One Gap (see con).
- AM, USB, LSB, FM Wide and FM Narrow Modes.
- Internal Lithium Ion Battery with Built-In 4 Hour Charger.
- Excellent and Super Clean Overall Audio Quality.
- Superb 3.5 inch Color Touchsceen LCD with extremely useful display brightness and sleep management settings.
- Decent Ergonomics.
- Overall Sensitivity Equal to other Better Tabletop Receivers.
- Preamp and RF Gain Adjustment.
- Excellent AGC Performance with "Four" Preset Decay Rates.
- Excellent Stability.
- Excellent SSB and Manual ECSS Performance (see con).
- Direct Keyboard Entry that Allows kHz or MHz entries (also has backspace key).
- Excellent (NR) Noise Reduction Function (that is fully adjustable).
- Three "Preset" Bandwidth Selections that are Fully Adjustable from 50 hz up to 15 kHz (all independent of mode, except FMW).
- Decent Battery Indicator (with separate voltmeter display). 
- LOCK Function (push and hold the main tuning knob).
- Built in 50mm (2 inch) Internal Rear Mounted Speaker that Sounds Good.
- FM Stereo with Headphones.
- All Mode Squelch.
- 50 Easy to Access Memory Channels (5 Banks or 10 Each) that Store : Frequency, Mode, AGC Setting, Bandwidth, Tuning Step, PreAmp, RF Gain Setting. (see con).
- FM RDS (Radio Data Service) Function (FM Broadcast Band).
- 24 Hour Format Clock with Seconds.
- Frequency Display Error Correction and S-Meter Level Adjustments.
- Eight Preset Audio EQ Settings (that work in all modes).
- Built in CW Decoder that works Decently (once mastered).
- 160 kHz Bandscope (with Waterfall) which is more than Wide enough for SW/HF use (see con).
- Includes a well made 19 Inch SMA Telescopic Antenna (perfect for Amateur 2 meter use).

CON :
- Limited Dynamic Range (with larger resonant outdoor antennas).
- Disconcerting LCD Backlight Interference which affects Mediumwave and Shortwave Bands (improved with firmware 1.0f).
- Other Spurious Signals With Whip Antenna in use.
- Local Strong Medium Wave Bleed Into Shortwave Spectrum (see text).
- No Synchronous Detection Mode.
- Bandscope of 160 kHz limits use for FM Broadcast (adequate for MW and HF bands).
- 1 hz digit even if on the LCD Display is not tunable (10 hz is the minimum tuning step / frequency).
- No Protection Feet on Rear or Bottom of Cabinet Provided (easily added).
- Frequency Coverage Gap Between 250 and 400 MHz.
- SMA Antenna Connector Threads are on the Short Side (certain SMA Connectors / Adapters may not tighten up).    

- Mechanical Encoders Quality Questionable (test sample main tuning encoder had a minor tight spot In rotation).
- No Antenna Attenuator (only available with option board).
- Memory Channels Lack Alpha Tags.
- No Manual or Automatic Notch Filter.
- No Fixed "Line Level" Output (see text).
- Updating Firmware Is Not for the Faint of Heart and could Buffalo some (see text).
- Known Firmware bug with 1.0d and 1.0e receiving VHF frequencies (see text, fixed as with firmware 1.0f).  

- No Official English Owners Manual (have to make do with a translated version).
- Purchase Can Only Be Made via the Russian Developers (a couple of months for it to be made and then shipping time).


What is a "Malachite-DSP" Radio Receiver ?

Is a portable near pocket sized STANDALONE (no computer required) "Wide Coverage" DSP radio receiver using SDR software (software defined). Includes it's own color 3.5 inch LCD touch screen , internal lithium ion battery with charging circuit and constructed in a robust lightweight metal case. Also contains a fairly large built in speaker on it's real panel. Most importantly it was designed to be sold at a reasonable price. Yes, it is truly designed and constructed in Russia.

It was developed by :
- Georgy Yatsuk - RX9CIM (Idea, DSP and general circuit design)
- Vladimir Gordienko - R6DAN (GUI and Control)
- Vadim Burlakov - R6DCY (schematic refinement, wiring, construction)
- Igor Naumenko (troubleshooting)

Key Features as listed in the Owners Manual :

1. SDR Architecture - The functionality is determined by on board software.
2. Frequency Coverage : 50 kHz to 250 MHz and from 400 MHz to 2 GHz.
3. Receiving Modes : AM, USB, LSB, NFM, WFM.
4. Additional Features :
RDS function with firmware 1.0b and up. Built in Morse Code Decoder, Variable filter width, adaptive squelch, threshold squelch, Noise Blanker, AGC, equalizer, FM Stereo with headphones.
5. Mirics MSi001 multi mode tuner IC to achieve low cost.
6. Powerful STM32H743 Microprocessor with a clock frequency of 480 MHz.
7. 3.5-inch display with a capacitive touchscreen.
8. Built-in selectable pre-amp.
9. Receiver control is achieved with 2 FRONT mounted rotary mechanical encoders (push in type) with a LCD touch screen.
10. Operational Power provided by internal lithium ion battery and or via USB (charging via USB). Capacity of the built-in battery is at least 1500mAh.
11. Low Power consumption - 300mA when using headphones.
12. Top mounted female SMA jack for use with telescopic or external antennas.
NOTE : For improved HF reception with the (high impedance) telescopic antenna an board is available at an additional cost
This additional PC board adds :
- 4 "Front End" filters:
- LPF 500kHz
- Bandpass filter 500-1500kHz
- Bandpass filter 1500-4500 kHz
- HPF 4500 kHz
- An attenuator, adjustable in the range of 0-30dB with a step of 1dB.
- A source repeater with switching elements.
(The optional board is designed to fit inside the regular receiver case)
13. Micro B USB for connection to a computer with the ability to transfer CAT, IQ and audio.
14. 160 kHz spectrum display span with scalability.
15. Sensitivity - 0.3 μV at frequencies up to 1 GHz.
16. Dynamic range approx. 85dB, due to characteristics of the Mirics MSi001 IC.
17. Robust aluminum body.
18. Display backlight control.
19. Dimensions : 120 x 88 x 39mm (4.72 x 3.46 x 1.53 inches).

First Try Was With Chinese Made Copy - Disaster Result !
First experience with these low cost self contained SDR devices was with a Chinese made "copy" of the original Russian made device that we cover here (see photo below). As this report was being complied there were no fewer then 7 different variants of them in existence on ebay (and elsewhere on the internet). Does not appear that no 2 are the same, and we are talking about the internal PC board that is used not the outer case which also varies greatly. From viewing and comparing the PC board pictures as posted on line it appears that parts count varies greatly.

The acquired REV B.0 marked Chinese test sample was outright disaster from right out of the box. Came with totally unacceptable operational firmware, downright missing stuff that the test firmware should have had and just poor performance on HF.

First off the the Menu > Hard, we only had 4 items (should be 8). We were not able to set the clock, that Menu selection has a totally blank screen. Yes our test sample is downright missing menu items that SHOULD be in the basic test firmware but was not !

Other Issues Include : 
1.-  On AM modes in HF / SW bands the actual received frequency is displayed 25 kHz higher than it actually is. (Example on 6.070.000 MHz is received at 6.095.000 MHz)
At 162.000.000 MHz area (FM Wide mode) it's 30 kHz off (high). We found no way to adjust these display errors. Again was missing menu items to correct this.
2. - USB and LSB modes were totally reversed.
3. - LSB Mode display is off LOW 2.5 kHz
    - USB Mode display is off HIGH 2.5 kHz
(Example : 1.490.000 MHz LSB is zero beat on 1.477.500 and 1.490.000 USB is zero beat on 1.502.000 MHz
(keeping in mind again that the USB and LSB modes are also backwards)
4.- Spectrum Scope is BACKWARDS (low frequencies are displayed high etc.)
5.- Both RUBBISH thumbwheel encoders are loose feeling, extremely fiddly and sometimes make poor contact that is a hit or miss sometimes (PITA). Unacceptable they are !
6.
- Spurious signals were all over the place on HF (external antenna using coax feedline).


Our Test Chinese Malachite (Malahit) SDR Test Sample (REV B.0) was TOTAL RUBBISH !
(click on photo for a larger view) (N9EWO Photo Edit)


Attempted to update the firmware but it locked up and became a brick (it did not even load into it). We were unable to find a EASY way to get into this SDR to flip the "boot" switch with the "soldered together" "PC board material" case without destroying it. A totally unacceptable case design it is ! The Chinese manufacture was totally unhelpful and downright rude (using contact email address as found on it's rear cabinet).


Internal photo of the Chinese Malachite (Malahit) SDR "REV B.0" Test Sample.
  Internal photo shows (compared to other Chinese SDR version photos on ebay/or the original version) that the parts count is FAR LESS less here. (click on photo for a larger view) (N9EWO Photo)

Mr. Saitou in Japan discovered (sadly this information came after the test sample was well in the trash can) that this Chinese B.0 version has major hardware manufacturing defects, as he covers that here with pictures and a detailed description (translator required). This can be repaired by the electronic handy and with the right equipment and good vision (however most will be unable to do this). But life to too short to deal with total rubbish like this, so "Caveat Emptor" (Buyer Beware) is in full effect here with ANY of the Chinese made versions. PLEASE NOTE : We did not test any other "Chinese" version at the time this report was compiled.

A RARE "5 Volt" CLEAN LINEAR USB Power Supply (for general operation)

Before we dig into the details on this receiver first lets cover a nice QUIET non switching power supply to use with it first (for those who use 117 VAC for mains power). We have covered this topic in the past with other radios that use a USB socket for operational power. What to do about the excessive RF noise that ALL switching AC adapters emit for use with a HF receiver ? CCrane in California USA still has available (at the time this report was assembled) an excellent, RARE and fairly inexpensive ANALOG / LINEAR / REGULATED 5 V 900ma USB power supply that provides enough “cool” and CLEAN current for operation with receivers that use a 5 pin MINI USB socket (CCrane Item # CWTPLP, Model: SR0509U). Yes it has a good old power transformer and linear type regulator. If one is handy enough, can add four .01 disc ceramic capacitors across its internal 4 power rectifier diodes to make it even cleaner (kills off diode hum for close indoor antennas, see photo). We just soldered them across the top of each of the diodes. But this is not a requirement of course AND DONE AT YOUR OWN RISK ! Please Note : This adapter only comes in a 117 VAC input USA version. Sorry, we are not aware of any 220-240 VAC version.


Super RF quiet LINEAR 5 V AC Adapter with MINI USB connector (left). Sold by CCrane in the USA.
Hefty 900ma Output. CCrane Item # CWTPLP, Model: SR-0509U (subject to availability).
Right photo shows 4 - 0.01 disc-ceramic capacitors added to
 reduce rectifier hum with indoor antennas on MW and HF.


The downside is that the CCrane power supply has a MINI USB output cable and you need a MICRO USB for this Russian SDR so of course it will not work out of the box. Not to worry as we located a nifty but very rare 3-foot (1 meter) Mini to Micro USB converter cable that does the trick perfectly from YCSbasics also in California USA (Product ID: A5575Q Part Number: U2JH3-B). Having a length of cable and not some adapter right at the radio helps to relive stress off the receiver’s USB socket. Please Note : This patch cable was difficult fro purchase at the this report was being typed (do your own internet searches for an alternative cable or adapter). Alternative adapter here but a warning here that it will be more stressful on the receivers USB socket (so be very careful).


YCSbasics 1 Meter / 3 Foot USB Cable Adapter
USB 5 pin micro male to USB mini 5 pin female
(Product ID: A5575Q Part Number: U2JH3-B)


IMPORTANT - WARNING ! : With the operational current consumption approx. 300ma (as indicated in the manual), normal operation with this CCrane AC adapter is no problem at all. However when charging the internal lithium ion battery, current jumps to around 850 ma PEAK (NOTE : RECEIVER OFF) and makes this supply operate HOT and near it's maximum rating ! It would be a good idea to use a 2 AMP USB switching type adapter when charging the internal battery
to rule out any possible heat failure problems down the road of the linear power supplies regulator.

Solid Case / Front Mounted Encoders / Large Rear Mounted Internal Speaker / Cool Operator

Housed in a solid metal
aluminum body with a very attractive outer anodized black color. It is held together with 8 metal screws for easy access. But of course one only needs to remove 4 of them for EASY rear panel access (say to jumpers 1 and 3 on the PC board). Being in all metal case rules out the use of any MW internal loopstick antenna and it does not offer this.

The two mechanical smooth type "Volume" and "Tuning" encoders are FRONT mounted where they should be. These encoders also have a "push in" function so as normal a bit of "side to side" play exists (but is not of any excessive level). However we have to question the quality of the encoders used, as with the test sample tuning encoder was slightly tight in one area of rotation (time will tell here of course). The 2 different size plastic knobs are of a push on variety (use no set screws).

Internal rear mounted
50mm (2 inch) 4 ohm 3 watt speaker is provided. It is missing any felt or fine mesh screen protection in the front of it for dirt / dust penetration. On the right side of the cabinet is a single dual color LED for charging status (RED and GREEN) of the included internal Lithium Ion battery. a on-off "tac" type button, plastic mini type stereo headphone jack and a MICRO type B USB socket for power and computer connection including firmware updates.

NOTE : One MAY need to plug in the internal battery on receipt to the PC board. This is (was) done deliberately for safety reasons and as covered in the owners manual.

Cabinet remains cool to the touch even after hours of operation. So no heat issues and is nothing to be concerned about.

Arrived Fully Assembled / Kit Versions are Available


Receiver was received fully assembled ready to go out of the box. It normally comes loaded with latest firmware for instant fun (no activation is required).

There are kit versions available and in this case the owner downloads and updates the receiver with the latest firmware (link and procedure both provided in the owners manual). Also it is important to point out that activating the firmware is FREE for those who have fully developed their design or a specific receiver is assembled from a printed circuit board purchased from the authors. For those who have purchased one of the rouge Chinese copies and desire the correct firmware, then a cost is involved ($ 55. USD at the time this report was compiled, see email address at the bottom of this report).  

PLEASE TAKE NOTE : Be sure and FULLY understand the firmware update procedure before hand. What will appear on the LCD screen after the firmware update is completed is : "THE DEVICE SOFTWARE HAS NOT BEEN ACTIVATED" with 32 numbers in green below this text. These numbers are to be forwarded to the developer (email again as given in the owners manual) where you will receive a 16 digit code back to enter in. This only needs to be done once, so will not be a needed for all future firmware updates.
(Please Note : This procedure may have changed by the time you read this).
        
Firmware Updates : Could Buffalo Non Computer Folks / ST Program 64 Bit Driver Bug / 3 Times to Power Up - firmware 1.0d and 1.0e only

Microsoft Windows program that is used to accomplish firmware updates is not intended for consumer use. It's a application that is targeted for developer programming called STmicroelectronics “DfuSe application programming interface”. Finding the required driver located within the software is a bit daunting to install and as we unexpectedly discovered (version  3.0.5). Was unable to install the required driver with a 64 Bit driver at all on a Windows 7 computer with a Intel Processor. The 64 Bit driver is marked as "amd64" ? Anyway in order for us to get it to work, it was required to use a 32 Bit Intel processor computer which a HQ Windows 7 laptop was. Then all was well. NOTE : Your situation may well vary here, but this was our experience in testing.

It is possible to use the alternative Stm32CubeProgrammer as well (as recommended by the developer RX9CIM) . It has been reported to be is more friendly and more simple to make happen (not tested). This information is not found in the owners manual at the time this report was compiled.

Firmware used with the test sample was 1.0d. With firmware versions 1.0d and 1.0e (only) It requires that the power button be pressed THREE (3) times to power ON. This was done to prevent undesired operation when moving it around. However with firmware 1.0f it was returned to just one press to turn on.

To power OFF, one pushes the same "tac" switch for approx. 3 seconds until a CW stream is heard in the speaker.

Firmware Bug with 1.0d and 1.0e - Receiving VHF

A firmware bug as reported with version 1.0e by Vincent Tutor (via Facebook user group) and as also experienced with the 1.0d test sample. When listening to MW (AM Broadcast) signal on say 1120 kHz and then switch to say a VHF frequency (example: USA 162.550 weather channel) using direct keyboard entry the receiver turns dead. If a memory channel where a VHF 2 Meter frequency has already entered is accessed, then AFTER enter the say 162.550 MHz frequency via direct keyboard entry, THEN it receives normally. Oddly this does not effect higher frequencies say in the 460 MHz area. Obviously this is a firmware bug. Another way around this bug is to store one 2 meter frequency and then the desired 162 MHz frequency in Memory (access the 2 meter one first then the 162 MHz one after). Anyway for the record and the way around it for listening in the VHF High Band area. UPDATE : This bug was fixed as with firmware 1.0f.

Basic Architecture using a
STM32H743VIT6 Microprocessor / MSi001 Receiver IC / Internal Speaker / No Line Audio Output

RTL-SDR.COM sums up it's basic circuity layout as :


"This SDR runs on the MSI001 tuner chip, which is the same tuner chip used in the SDRplay line of units. However, unlike the SDRplay units which use a wideband MSi2500 ADC, the Malachite-DSP uses an audio chip as the RF ADC. This provides a 16-bit ADC, resulting in high dynamic range, but at the expense of the available bandwidth which is only 160 kHz. A STM32H743VIT6 with ARM Cortex A7 processor runs what appears to be custom DSP and GUI software. The software doesn't seem to support DRM, but AM, WFM, NFM, LSB, USB are all supported."

The stereo audio codec used is a NUVOTON (or equivalent manufacture) NAU8822. It's integrated BTL speaker driver can provide a hefty 1W output. The TOTALLY independent stereo head-phone driver to it's 1/8 inch phone jack is 40mW (at 16Ω). This does a not allow for anyone to use a external speaker to be directly driven with the headphone output. So if you desire to use a different external speaker it will have to be a stereo amplified type using it's headphone output jack.

Excellent part here is the output can be selected to have either Speaker output on, Headphone output on or OR BOTH (just tap that icon area to toggle). This works out great as the headphone out can also be used for a always connected "defacto" line output to say feed a external audio recorder. One just has to remember that the volume control will affect the output level here (it's not fixed). NOTE : In practice to archive proper "Line Level" this way (without having to turn up the volume control to a excessive level) an external audio preamp was added and then was easily brought up to a proper level without have to blast the speaker audio. Preamp used / tested was the Rolls MP13 (using it's 1/4 inch phone jack inputs/outputs).

Front End Filtering / Optional "high Impedance" Front End Board / Included 19 Inch Whip Antenna

There are seven "front end" filters used.
- 0 to 12 MHz
- 12 to 30 MHz
- 30 to 60 MHz
- 60 to 120 MHz
- 120 to 250 MHz
- 400 to 1000 MHz
- > 1000 MHz

If this sounds vaguely familiar, it has the same identical "front end" filter scheme as used in the "original" SDRPlay RSP1 receiver.

For improved HF reception with a (high impedance telescopic antenna) an add on board is available at an additional cost (approx. € 45. , about $ 55. USD + shipping) and fits inside the regular receiver case (not tested). For more information on this option please contact Vadim Burlakov direct (email : [email protected]).

This optional PC board adds :
- 4 "Front End" filters:
- LPF 500kHz
- Bandpass filter 500-1500kHz
- Bandpass filter 1500-4500 kHz
- HPF 4500 kHz
- An attenuator, adjustable in the range of 0-30dB with a step of 1dB.
- A source repeater with switching elements.

Included 19 inch Whip Antenna use is perfect for use in the 144 MHz amateur and above. Of course it's no good for any MW / HF / SW listening. Also whip use at lower frequencies is awash with microprocessor and LCD noise (external antenna using coax cable is a must).

Near Full Spectrum Frequency Coverage with One Gap / All Modes

This original Russian "Malachite-DSP" frequency coverage is near DC to Daylight from 50 kHz to 2 GHz. Gap exists between 250 and 400 MHz. So for Military Air fans this will be a disappointment. Unlike most scanner receivers sold in United States, there are no gaps in the 800 MHz part of the spectrum. 

Modes provided are standard AM, USB, LSB, FM Wide and FM Narrow. As is the case with most SDR sets, this is totally independent of frequency. So one can use NFM or WFM of HF if desired.

Accurate Battery Indicator

In the upper hand corner on the LCD there is a battery icon that indicates remaining capacity. It's unusually accurate. It has a 3 color status. Green for good, Yellow for mid and Red for limited charge left. if the "Vbat control" in the HARD menu is set at "Standart" (Default) - the receiver will shut off automatically when the supply voltage drops to 3.3V. Prevents total discharge of the battery.
"Battery Low" text is displayed in the Spectrum Scope area when it's about to be shut off. In the "LOW" setting (not recommended) - The receiver will continue to work below 3.3 Volts until it does not allow components to operate. This is not good for the Lithium Ion battery and could lead to premature failure.

TIP : The actual current battery voltage measurement is available in the HARD MENU (upper right hand corner).

It took 4 hours for the internal battery to recharge in testing, receiver OFF (starting with auto shutdown).


From mid-September 2020 the developers mainly use the popular round 18650 type
lithium-ion battery (approx. 2000 mah). The battery holder is custom made using a 3D printer. (RX9CIM Photo)


Beautiful Large 3.5 Inch Color Touchscreen LCD / Spectrum Scope with Waterfall / Excellent Backlight Management / LED Backlight Interference Issue

Beautiful super sharp full color 3.5 inch LCD includes touch screen operation that also works with very little finger pressure. it includes many features for backlight control and for maximum user enjoyment.

Spectrum bandwidth is 160 kHz total with 3 scale settings (X1, X2 and X4). The scale settings allow for more detail and is very useful. This scale setting Is toggled with a tap of the waterfall area. Some will find the 160 kHz maximum bandwidth very limited. While this is true for VHF-UHF frequencies, with MW and HF bands this is of little moment (is more than adequate to be extremely useful).

Translated owners manual information on the backlight :

- Backlight brightness has adjustment - minimum and maximum value.
- The time after which the backlight level will be reduced to minimum (dimmed) value.
- The time after which the backlight will be turned off completely.

To change the settings, go to the VISUAL menu. Changes parameter values are performed using the encoder ENC_VOL.
To set the minimum backlight level, you must select the "BRIGHT MIN" parameter.
To set the maximum (working) value of the backlight level you must select the "BRIGHT MAX" parameter.
To set the time after which the level will change backlight from maximum to minimum, you must select the parameter "REDUCT TIME".
To set the time after which the backlight turns off you must select the "SLEEP TIME" parameter. This time is set relative to the "REDUCT TIME" parameter. Complete shutdown possible only if the backlight is turned off completely.
To turn the backlight off function on or off you must select the "LCD SLEEP" parameter. The value of the "LCD SLEEP ":

- Enable -  Function of completely turning off the backlight is enabled;
- Disable - Function of completely turning off the backlight is disabled.

The sleep function is easily deactivated (reset) by just taping the touch screen.


One can adjust the amount of Waterfall percentage (vs. the Spectrum Scope) viewed on the screen. Also the color of the Spectrum Scope Screen trace (Yellow is Default, the author prefers Green, easily changed) as well as the height (sensitivity) of the Spectrum Scope trace. Spectrum Scope fill can be turned off as well (as default). Called "FFT Fill" in the VISUAL SETTING menu.

"Fly in the Pie" here is with the LCD backlighting. Even using proper coax feedline and battery operation, interference created by the LCD's LED back lighting was experienced in the Mediumwave and lower Shortwave bands (AM Mode). It sounds like a low level constant heterodyne. With strong signals this gremlin will not be detected. Were only able to eliminate this interference completely was to turn up the BRIGHT MAX up 95 or 100 in the VISUAL SETTING menu. Good news is once the BRIGHT MIN kicks in (user adjustable for the time this happens) the interference is reduced with any lower normal backlight settings but keep in mind it does not totally disappear either.

Mind you this is a known hardware issue and at it's price point is not a glaring drawback (not a deal breaker).

UPDATE : This
minor MW / SW backlight interference is less of a problem as one tunes up in frequency. By the time you get to the 31 meter SW broadcast band it’s near non existent. Tends to be in "cluster – blobs" (that is it does not destroy the entire band when it occurs). Also it is indifferent (varies with band conditions). Using manual ECSS mode (zero beat using LSB/USB modes) helps to reject this a bit. Again at it's price point this should not be considered a major drawback.  NOTE : This issue was addressed with firmware 1.0f.


TIP : A quick way to turn OFF the LED backlighting is
one quick tap of the power button. Another tap to turn it back on (NOTE : Also may need to touch the LCD if it does not return after the second tap). 

N9EWO MP3 Audio File : LED Backlight Interference
Here is a 20 Second MP3 recording of "Radio Havana Cuba" (Shortwave Band- 49 meter band at night) made with the test sample that clearly shows this LED Backlight interference. External antenna and not in any overload situation (coax feedline). Signal strength was not super strong here. Most stronger signals will not be affected by this bug which is detected in the Medium Wave and to the lower SW / HF bands (oddly in the AM mode). Backlight as ON and then switched OFF (after the beep). This was with firmware 1.0d (later versions this bug has been improved).
 
Decent Ergonomics / Direct Keyboard Entry / 10 hz is the Minimum Step - Tuning Resolution

Ergonomics are first rate. Everything is logical and straight forward for such a small cabinet. Direct keyboard entry (tap the frequency display area) is a royal treat and will accept entries in kHz or MHz along with a backspace for entry "boo-boo's".

The frequency display shows resolution down to 1 hz. However the receiver will not tune this fine period. So it has 10 hz as it minimum tuning step and display. This is a slight drawback to it's otherwise excellent manual ECSS and SSB performance (more on this later).

Sensitivity / 3 Preset Bandwidth Selections / Extremely Stable
 
Sensitivity is as good as any other modern communications set as compared to at HQ (including the wideband Icom IC-R8600 as reviewed here). See Preamp use as covered later in this report. Excellent.

Selectivity is razor sharp and has a similar scheme to what Icom uses. That is 3 preset fully adjustable selections (NARROW-NORMAL-WIDE). Even if there is no dedicated CW mode, one can archive proper bandwidth with no problem. These can be selected via the "AUDIO SETTING" screen or accessed by pushing in the Volume encoder  knob. Excellent once again.

Each bandwidth setting has "Low Frequency "and "High Frequency" adjustment (in 50 hz steps). Good news here is that one can adjust SSB and AM bandwidths up to 15 kHz for when conditions warrant for greatly improved audio quality.

NOTE : In "FM Wide" mode the filter is fixed at a single bandwidth (not adjustable even if the adjustments can be done in the AUDIO SETTING). Unknown what the lone bandwidth is (guessing around 170~190 kHz ?). In any event it has excellent razor sharp performance.
FM broadcast performance was right on par with the Icom IC-R8600 ! That is near breathtaking with sensitivity and selectivity (external outdoor antenna's).

Rock solid stability was observed from cold start up. Impressive and puts most (if not all) other consumer portables to shame. Not aware of any TCXO being used.

Limited Dynamic Range /
MW Intrusion into SW Local MW Bleed Through Into SW Spectrum / No Attenuator

Dynamic range is adequate on the HF bands under most conditions and using modest outdoor antennas. However during peak nighttime conditions on shortwave-HF, if the RF Gain was up too far
(and or the Preamp on which is big "no no" on MW and most of HF) and using the test 55 Foot MLB antenna, nasty excessive overloading occurred. Backing off the RF gain and or shutting off the Preamp usually cured the nastiness here.

The manual gives this RF Gain Control recommendations (we find sometimes 0 is the best choice during peak nighttime listening with a decent outdoor antenna.):

Recommendations:
1. The "LNA / MIX1 GR" and "MIX / MIX2 GR" parameters inherently work like attenuator and it is advisable to use them when working with long antennas, or in case of receiver overload, which is expressed in the form of receiving false stations.

2. It is not recommended to use RF GAIN more than than 40 when working on short telescope antennas and more than 20 when work with long antennas.
 
A RARE exception to this was with a very strong local amateur station about 1.5 Miles (2.4 km) away using approx. 100 watts that pretty much killed the ENTIRE HF band no matter what we adjusted. T
here is no attenuator provided without the option board. But even adding a good EXTERNAL 20db attenuator did not help cure the problem when this bad. Only switching to lesser (much less) antenna controlled this extreme very local signal overloading. We did not try the "LNA/MIX1 GR " or "Mix / MIX2 GR settings (this may have helped here?) Again this was a very rare situation here mind you, but for the record. This overloading was non existent with the Icom IC-R8600 and on the same antenna.

Receiver is using the same identical front end filtering scheme and MSi001 TV tuner chip as with the discontinued SDRPlay RSP1 (original version not the A). So as it went with the RSP1
we experienced local strong medium wave (MW) stations bleed into the Shortwave spectrum with the larger test antenna's. With an external added 3.5 to 30 MHz bandpass filter it TOTALLY cured this issue. Also the same identical characteristics we experienced with the AFEDRI SDR NET PC receiver.

NOTE : This was not as bad of an issue as with the tested SDRplay RSP1 or AFEDRI SDR NET devices, but it was clearly detected in use. Again this interference will vary with any given location. Many may never experience it depending how close you are and strength of local MW station(s).


Chinese 3.5 to 30 MHz “Band Pass Filter” with SO-239 connectors (check on ebay or amazon).
Depending on where you live and antennas used , this may be a required purchase.
This will keep strong local MW stations out of the SW / HF spectrum.

Preamp - Use Conservatively (MW / HF) / Spurious Signals

There is a nice (20db?) preamp provided and is very useful more so in the upper part of the SW spectrum and above (say 10 MHz). However it's primary use was intended to be used in the VHF and UHF parts of the spectrum.

However under certain conditions is useful in the lower SW bands as well, but more times than not it will just launch the set into overload during nighttime conditions with any proper outdoor antenna in use.

Using this receiver as stock even with a long whip SMA antenna for the MW and SW bands is not so possible. Loaded with spurious signals abound from the Microprocessor and LCD. The optional add on board is supposed to help in this regard (not tested). See information given earlier in this report.

If using any kind of a decent outdoor FM broadcast antenna (and or live in a extremely RF rich large city location), best to leave the Preamp OFF.

Super Clean Audio Quality /
Eight Preset Audio EQ Settings / All Mode Squelch

General audio quality is extremely clean and hiss free. Plenty of punch with it's 1 watt speaker output. Large rear mounted 50mm (2 inch) speaker even gives a bit of Bass response. Volume control has many low settings so can work as a good nighttime radio.

There are no tone controls per say. however In the AUDIO menu there is a EQ TYPE adjustment that allow for eight preset tone adjustments : (EQ-OFF) SOFT, LIVE, CLUB, ROCK, BASS, JAZZ, POP, VOICE. This feature is marked for WFM use only, but in practice it works in all modes even USB and LSB. Yes just what you would see on a MP3 player.

All mode squelch is another useful feature. EQ TYPE and SQUELCH are both located in the AUDIO SETTING menu.

FM Stereo With Headphones / RDS / CW Decoder Function

FM Stereo with headphones or with a set of powered stereo speakers as plugged into the provided 1/4 inch stereo headphone jack. Stereo mode is easily defeated and has a indication for when FM Stereo is being received (when headphones are plugged in).

Firmware 1.0b and above has RDS (Radio Data System) feature. It is toggled on and off by touching the Spectrum Scope and of course only while in WFM mode. As normal it takes a pretty strong signal to properly read the RDS data. Works well enough, however we detected a low level background tone that is added to the received signal when engaged (firmware 1.0d).

While using the RDS mode the Spectrum Scope is switched to very slow rate and the Waterfall is disabled.

Built in CW decoder is also available and operates fine, but it takes a signal with no interference and a bit practice to get it set right. This is toggled in the MODE screen and then a "Min SNR" needs to be adjusted with proper "flash" indication of the white tune line on the LCD. No it's not going to deal well with badly sent CW and cannot expect to that. Still fun to have in it's feature set and very useful.

Frequency Display Error Correction and S-Meter Level Adjustments.

Test sample was only inaccurate about 2 hz HIGH in received frequency to what was actually displayed at 10 MHz which is stellar in such a low cost receiver. Located in the HARD menu is a setting called "F correct". Tune in to a time signal station such as WWV (exactly to it's proper frequency in LSB or USB using a wide bandwidth) then adjust the F correct setting.

As it always goes with many wide band radio receivers it was still slightly off (high) say in the UHF spectrum and above. But was well under it sounding off frequency.

Another extremely neat feature is a adjustment for the S-Meter calibration. User can make it less sensitive to match it up with another receiver / transceiver (less sensitive only not more). S-Meter
calibration was found to be decent out of the box with no adjustment's needed.

Excellent AGC Performance with "Four" Preset Decay Rates that are Fully Adjustable.

AGC performance is simply excellent as well. FOUR preset decay rates are provided (plus OFF) : FAST, MIDDLE, SLOW and LONG (super slow). No AGC bugs here , it's just pleasant overall even with weak fluttery signals in MW and HF bands.

With the "AGC OFF" switched on there is a "MANUAL GAIN" icon that becomes viewable on the screen (works in all modes except WFM). Works extremely well to help pull out the weak ones. Alternatively one can use the "AGC LIM" setting (AGC Fast) to also help in this regard without turning it OFF. Just remember to return this back down after to the 75 default (otherwise the AGC ,may experience pumping issues).
Also setting the EQ TYPE to VOICE helps as well for maximum audio recovery.

"AGC GAIN" is another setting available. It too can help to recover audio out of weak signals.

manual data :
AGC LIM - Maximum output sound level.
AGC GAIN - Amplification of the signal level in the AGC loop.

No Synchronous Detection or Notch Functions  / Excellent SSB and Manual ECSS Performance.

There is no Synchronous Detection mode offered (unlike with the AFEDRI LAN-IQ, current firmware). Good news here is with the extremely accurate tuning and excellent SSB performance along with decent stability, manual ECSS tuning and performance is simply first rate. It even excels MANY more modern tabletop sets here with just the SSB mode performance. So yes, that helps offset the lack of the decent Sync Detector to an extent (but not entirely). Having a 1 hz tuning step would have made this even better.

Also missing is
any kind of Notch filtering (manual or automatic).

50 Memory Channels (5 Pages of 10 Channels Each) / No Alpha Tags

You have 50 total memory channels available. There are spread out in 5 pages of 10 channels each.
Each channel stores : Frequency, Mode, AGC Settings, Bandwidth, Tuning Step, PreAmp, RF Gain Setting. Are very easily viewed and accessed, except for selecting the pages which is a bit slow using the main tuning knob.

No Alpha tags are offered. Having only 50 memory channels will be is a bit skimpy side for many. But having less here is not a bad thing which makes it for easier management (especially with no Alpha Tags).

Noise Reduction and Noise Blanker

One never knows when something near the listening location will be needed to combat local interference. The Malachit has a Noise Reduction (NR) plus Noise Blanker (NB) functions and work excellent.

When properly adjusted the Noise Reduction is simply breathtaking without the "Donald Duck" or garbled sounds. Cleans up static and other band noises decently. Just as with the AGC performance, it rivals or exceeds more expensive DSP sets tested !


Other Operational Notes

To fully reset the receiver : Will reset the current settings to defaults. Exit all menus and when the main screen is displayed, hold down both encoders (Volume and Tuning) until you hear a BEEP. All user settings, including those saved in memory channels cells will be lost.

To Set the 24 Hour Clock  : Clock setting menu is entered by by long pressing the HARD menu icon on the LCD. Moving through the menu items is carried out by clicking on the touchscreen. Parameter change is carried out using the VOLUME ENCODER.To save the set time values the VOLUME ENCODER is pressed IN and held until a BEEP is heard. Exit the general menu list by pressing the HARD button.

N9EWO "Wish List" (Future Models or Firmware Update ?)
- Improved Front end filtering as out of the box (to keep STRONG local MW signals out of SW)
- Add Synchronous Detection.
- Add a second VFO.
- Add 1 hz tuning step.
- Add "Line Out" jack (the
NUVOTON NAU8822  has this output available already)
- More robust on/off switch.
- Optical encoder used for main tuning.
- Less LED Backighting Noise.
- A easy to access audio MUTE Button on the LCD (however the current speaker/headphone toggle can work this way, however is small to access).
- Easier Access of Tuning Step Setting.(now is only pressing in the Tuning knob encoder)
- Auto Notch Function.
- Allow the owner to choose between one or three presses of the power button to turn on (menu selection).

Excellent "Standalone" SDR Performer for Price Point / Not Meant to replace any Modern DSP Tabletop Set / Order Direct From Developers

Some may say that this is a Icom IC-R8600 receiver in a pocket size case ? No, it surely is not and one should not expect that (but was a total surprise is some area's). However with the price point it was designed at this SDR/DSP device certainly does a yeoman's job and equals or excels most (if not all) SW portable radios for performance. SSB performance blows away most portables period if not some tabletop models as well. Overall AGC performance actually is much improved over the Icom IC-R8600 in testing. 

Taking a totally new idea with a "Standalone" SDR portable radio receiving device with a spectrum scope LCD, self contained lithium ion battery and internal speaker. The original Russian Manufactured
"Malachite" delivers this and at a very reasonable price to boot.

The LCD "LED Backlight" heterodyne noise was addressed (and improved) as with firmware 1.0f. If using a earlier firmware version it can be quite disconcerting when receiving weak "AM Mode" MW / SW / HF signals. However as we say again this was not considered a deal breaker if one cares not to update it (minor annoyance for the price point and being it's limited to MW and lower SW bands).

It may only be ordered direct from the developers in Russia. As of me typing this report, there is a waiting period. It can be shipped to most locations on the globe. For more information and current pricing, please contact
Georgy Yatsuk - RX9CIM (email : [email protected])

As comments made above (at the time this review was assembled) it is highly recommend that one should AVOID ANY of the Chinese manufactured "almost copy" versions as sold on ebay, Amazon and elsewhere. That is unless you love pain and grief.

Important Note : Please DO NOT confuse this review text above when compared to ANY of the Chinese "almost" copy devices. It very well may NOT (probably NOT) be valid. We have not tested any other of the Chinese devices (one test sample acquired was defective and badly designed, please see yellow block above).

Dave N9EWO
© N9EWO, all rights reserved
Ver 2.5

Internal PC Board photo of the original Malachite DSP SDR. (N9EWO Photo Edit)

Facebook Pages (English)

"Radio Receiver Malachite-DSP" - User Group Page for Russian Version (public)

"China Malahit / Malachite Users Group" - User Group for Chinese Versions (public)


Links for additional Information (all subject to change without notice)

(RTL-SDR.COM) "THE MALACHITE-DSP: A $195 RUSSIAN MADE PORTABLE WIDEBAND SDR RECEIVER WITH TOUCH SCREEN"

Malahit-DSP radio receiver - sharing experiences! (in Russian)

"General Schematic" (PDF Format)

FIRMWARE : Receiver Malachite-DSP

MALAHIT DSP portable SDR radio (November 2019 announcement via hamfourm.ru / in Russian)

(The SWLing Post) "The new Malahit-DSP: A portable all-in-one wideband SDR receiver" (Nov 2019 with reader updates)

English Operation Manual (August 2020 version)

Acrylic (plastic) "tilt" stand available from "Source One" TUCSON, AZ USA

3M Large Bumpon SJ5023 stick on feet (for rear panel)


You Tube Video's

George Yatsuk - RX9CIM Videos (in Russian)

MEET THE NEW MALACHIT DSP (in Russian)

RDS in Operation on Malahit


Overview of the Malachite DSP receiver (In Russian)

Receiver "Malahit" test CW decoder on 80 meter amateur band

Fenu Radio : Malahit-DSP & Afedri LAN-IQ "Head to Head"

MALAHIT DSP SDR VS SDRPLAY


4930 kHz VOA BOTSWANA

SDR "Visair" 10 Watt QRP Ham Transceiver in Operation  (New Project by the Malachite Developers)


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