This additional PC board adds :
- 4 "Front End" filters:
- An attenuator, adjustable in the range of 0-30dB with a step of 1dB.
- A source repeater with switching elements.
(The optional board was designed to fit inside the regular receiver case. These features and more provided with later DSP2 model as stock. See bottom of this page for details).

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

I will NOT be held responsible for any info that is listed here ALL DONE AT YOUR OWN RISK !

        
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.

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 (or at least were at one point ?) 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).

I will NOT be held responsible for any info that is listed here ALL DONE AT YOUR OWN RISK !

        
Firmware Updates : Could Buffalo Non Computer Folks / 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”. Carefully follow instructions as given in the translated English manual.

Be sure and use a decent quality SHORT USB-Micro cable with NO adapters (say 1m / 3 feet or under in length).

TIP (DfuSe version 3.0.5) : Install the PROPER USB Driver (32 OR 64 bit, Microsoft Windows 7, 8.0 or 8.1) BEFORE attempting any firmware upgrade. They are located in "Bin > Driver". Drivers are all "exe" installs. We used Windows 7 with a 32 Bit OS and had no driver or installation issues (going from firmware 1.0d to 1.10b and to 1.10c / 1.10c Rev2). Using a 64 Bit OS was not tested but reports that the 64 bit driver can have installation issues (if it can be installed at all?) on certain computers with DfuSe.

It is possible to use the alternative Stm32CubeProgrammer as well (as recommended by the developer RX9CIM). Not tested and may require Java (JRE only) to be installed. This information is not found in the owners manual at the time this report was compiled (see You Tube video link below). But via Mark KD9NXV this is the answer for 64 bit computers (and it's driver) including windows 10 computers. Again we have NOT tested this programming software with Windows 7 (or any other Windows operating systems).

IMPORTANT : Before performing any firmware updates , it is a good idea to shut off any anti-virus programs. This is especially important with the Stm32Cube program as it uses Java. Also be sure that a properly charged battery is installed before you start (of course any external USB battery cannot be used when doing firmware updates).

WARNING : FIRMWARE IS NOT INTERCHANGEABLE BETWEEN DSP1 and DSP2 VERSIONS !


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 and above it was returned to just one press to turn on. Later firmware has a way to restore the 3 presses power on but requires PC Board soldering. In testing we found ONE press to be MUCH more preferable.

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 ONLY - Receiving VHF

A firmware bug as reported with version 1.0e by Vincent Tutor 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 TOTALLY 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


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 (was?) available at an additional cost (not tested).


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, more information on this later).

With the later DSP2 version these features were integrated into the updated design (all added onto a single PC Board). Additional PC Board shielding was also added and other improvements. NOTE : We have NOT tested this DSP2 version. Please see photo's at the bottom of this page for internal PC board comparison and general parts layout differences as well as photo / additional information.

Near Full Spectrum Frequency Coverage with One Gap / All Modes

This DSP1 and the later DSP2 version of the Russian "Malahit - Malachite" 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 (CW / DSB and Sync added with later firmware). As is the case with most SDR sets, this is totally independent of frequency. So one can use NFM or WFM on HF if desired.

Accurate Battery Indicator / Charge Time

In the upper right 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). With firmware 1.10c and above this is displayed over the top of the battery charge icon in the upper right hand corner of the LCD.

It took 4 hours for a 2200 mah 18650 installed battery to recharge in testing, receiver OFF (starting with auto shutdown).


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 (so be it may need a extra 1/2 second to take, BUT only use a light touch). It includes many features for backlight control and for maximum user enjoyment.

Spectrum bandwidth is 160 kHz total with 3 scale settings. 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 :


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 (NOTE : Testing here based using EXTERNAL ANTENNAS with shielded coax feedline). 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. IMPORTANT NOTE : This issue was addressed with firmware 1.0f and reduced (more like nearly eliminated) with the later tested 1.10b. Downside is the LCD touch sensitivity has been reduced. So it takes a slightly LONGER touch to make happen (NOT HARDER).

PLEASE NOTE : If you make use of a whip antenna and or close indoor antenna's around the receivers cabinet then you will receive disconcerting noises emitting from the microprocessor and LED backighting circuity on the MW and SW bands. Our test sample did NOT have the optional PC Board for proper testing with whip antennas and plus we used external antenna's (with shielded coax feedline) for most of this hands on test report. But were easily able to detect excessive RF interference even without the option board (so less less sensitivity) with whip use as attached on the top of the receiver.

Firmware 1.10d added a "EMI Reduction" toggle in the HARD menu.

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 with coax feedline and not in any overload situation. 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 greatly reduced).

 
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".

Some may call it's general operation difficult or "finicky". But most owners should adjust to that with some use ?

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 (UPDATE : CW mode was added with later firmware versions), 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.

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 / 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 :

 
A RARE exception to this was with a very strong local amateur station about 1 Mile (2.4 km) away using approx. 100 watts that pretty much killed the ENTIRE HF band no matter what we adjusted. There 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. As recommended above using the "LNA/MIX UP GR" and or "MIX GR" settings in HARD / Setting Mode cured any overloading but of course with much less sensitivity. 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).

TIP : In testing when receiver overload was detected we found to activate the "LNA/MIX UP GR" and or "MIX GR" and carefully increase the "RF Gain" to recover some of the loss sensitivity. Yes this is downright weird but was very effective in testing ("PREAMP" OFF).
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 (as covered above). Loaded with spurious signals abound from the Microprocessor and LCD backlight. 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, downright excellent it is. 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.

We found connection to a AMPLIFIED set of computer speakers GREATLY improves the audio and can hear how fantastic the overall audio quality really is ! This is highly recommended for any home use.

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

With FIRMWARE 1.10c a "Audio out" selection was added in the main menu. Allows for easy toggle between the INTERNAL SPEAKER (Speaker) or HEADPHONES (phone) or BOTH (Ph+Sp). Nice touch but one can still select these on the touch screen as difficult as that can be as it's sure a tight area.

FM Stereo With Headphones / RDS is Mixed Bag / 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. PLEASE NOTE : It takes a extremely STRONG signal in order for RDS to function (firmware 1.10c). We detected a low level background tone that is added to the received signal when engaged with firmware 1.0d (thankfully this was completely fixed with later firmware).

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 it to do that. Still fun to have in it's feature set and very useful but keep in mind it will take some adjustment to make work.

Frequency Display Error Correction and S-Meter Level Adjustments.

Test sample was only inaccurate about 2 hz HIGH (with firmware 1.0d, was 26 hz HIGH with firmware 1.10b and 1.10c for some reason) 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 (plus OFF).

AGC performance is simply excellent as well. FOUR preset decay rates are provided (plus OFF) : OFF, FAST, MIDDLE, SLOW and LONG (super slow). No major 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" that can still be adjusted (works in all modes except WFM) that works extremely well to help pull out very weak signals. Alternatively one can use the "AGC LIM" setting (in AGC Fast) to also help in this regard without turning it OFF. Just remember to return this back down after use 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.

TIP : When turning OFF the AGC completely , be sure and return the "MANUAL GAIN" back to ZERO when finished. Otherwise the audio may blast when you go to use it next time.


FIRMWARE 1.10c added a new PGA selection (PGA BST) and PGA Gain adjustments (unknown what these are for, so no touch and leave alone).

Excellent Double and Selectable Synchronous Detectors (with second firmware 1.10c Rev2) / Auto Notch Filter (all modes with firmware 1.10c) / DSB

With 1.10b firmware "Double Sideband" Synchronous Detector was added. After careful listening and scratching our head for a long awhile if it was dong much of anything, have determined that it's wash (it does not do anything). Does not even appear to be even a "SynchroPhase" type of a detector ? Good news is any fading distortion is very low anyway in the standard AM mode.

Firmware 1.10c added "Selectable Sideband" Synchronous Detector (selectable Upper and Lower). Sadly this was also a complete wash. That is it's completely useless to reject ANY adjacent channel interference (also does not do anything at all in fact, maybe raises the audio high end up slightly). Even the ICOM IC-R8600 fairs MUCH better here (it works to at least tame co-channel interference decently.). Just use the excellent manual ECSS as covered below.

IMPORTANT UPDATE : Good news is that with a second 1.10c firmware update on July 26, 2021 (what we call 1.10c Rev2), Double / Selectable Synchronous Detection is NOW working and performs excellent as well. Holds lock on the weakest of signals too. Now able to tune out interference from the adjacent sideband as well as decreasing fading distortion. PLEASE NOTE : What I call Rev2 of the firmware 1.10c is my own marking. This updated version of 1.10c has no different file name to indicate the revision.


A "DSB" mode was also added with 1.10b firmware, however I do not see the purpose / use for this  ? It can be activated with AM or SSB modes. If someone can enlighten me on this, please let me know.

Auto notch filter was also added with firmware 1.10b. Works excellent with CW/SSB modes. We were unable to get to work with AM signals. However starting with firmware 1.10c AM mode auto notch was added and also works excellent.

Excellent ECSS Performance with firmware 1.0d only to get zonked with 1.10b (fixed with a simple menu adjustment tweak)

Excellent (manual) ECSS performance was experienced with firmware 1.0d (no issues at all). This is of course using LSB or USB mode zero beating a AM mode broadcast station. However that took a dive with the also tested 1.10b firmware. A nasty BUZZ was heard with any medium or strong signal. We tried to decrease signal level / RF gain etc. with no difference. Have a listen to the audio file below as recorded from the HQ test sample. This can be a bit indifferent and cannot be detected with weak signals . We hope this bug gets fixed with a future firmware release ? NOTE : For some strange reason when DSB is selected with LSB or USB this buzz disappears. But then there is now a out of phase like sound that is present (weird it is).

TIP : The cure that eliminates this bug entirely is to be sure that the  IF filter "Low Freq"  settings are adjusted up to at least to 150 hz (not at zero where I was using it at) . This issue then completely disappears ! Yes strange it is !

N9EWO MP3 Audio File : ECSS Buzz with  Firmware 1.10b / 1.10c

Here is a 21 second MP3 recording (Shortwave Band- 49 meter band at night) made with the test sample that clearly shows this ECSS Buzz (SW AM mode broadcast station in LSB - zero beat) ! External antenna and not in any overload situation (coax feedline). Most WEAK signals will not be affected by this bug. This was with firmware 1.10b and 1.10c (earlier tested 1.0d firmware was perfect with ECSS use, had none of this). See the tip above for the simple MENU tweak to fix this bug.

  
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 / SDR sets tested !

Watch Out for Stress on Internal U.FL / IPX Antenna Connector

Just as with the SDRPlay family of receivers the Malachite / Malahit uses a extremely TINY and very fragile "U.FL / IPX" female plug to bulkhead female SMA patch cable. With the SDRplay products they use a fairly long and flexible cable from the SMA female socket to the PC board. On the other hand our Russian Malachite / Malahit test sample used a very short and EXTREMELY STIFF jumper cable. This oversight led to bad INTERMITTENT connections over a few months of use with no reception with the test sample.

We were able to CAREFULLY shape (bend) this extremely stiff cable enough to relive the great stress off of it to make work again, however (depending on what your sample is using here, this could be variable?) one is probably best to source a more flexible replacement connection cable here (just a tad longer say 6 inch length cable would be a good idea as well) ?). PLEASE NOTE : The FEMALE U.FL / IPX connectors only have a 30 mating cycle rating before replacement. So keep that in mind as well.

I will NOT be held responsible for any info that is listed here ALL DONE AT YOUR OWN RISK !

        

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. (IMPORTANT NOTE : DO NOT have it connected to a USB port on a PC when this is attempted.)

To Set the 24 Hour Clock  : Clock setting menu is entered by by long pressing the HARD menu icon on the LCD (firmware 1.10b). 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.

To turn OFF the Spectrum Scope and Waterfall : This toggle can be handy for reducing or eliminating self generated interference as well as increasing battery life. This is accomplished in the VISUAL menu, then select "Pan&Wtf" to "Disabled".