Tag Archives: Dan Robinson

Radio Waves: 20K Hz & The Buzzer, Cuba Jamming, Rugby Radio Station soon a school, HRO Opens a store in FL, Police Use Morse, Tool Box Spy Radio, and “Einstein Listened”

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Paul, David Goren, Pete Polanyk, Ulis Fleming, Troy Riedel, Tracy Wood, Dan Robinson, and Kris Partridge for the following tips:


The Buzzer (Twenty Thousand Hertz podcast)

This episode was written and produced by Olivia Rosenman.

Since World War I, countries around the world have been broadcasting mysterious numerical messages via shortwave radio. Though concrete evidence is hard to come by, the general consensus is that these coded messages are meant for undercover agents operating abroad. And one particular Russian station may have an even more sinister purpose. Featuring computer engineer Andrus Aaslaid, historian Maris Goldmanis, and documentary photographer Lewis Bush.

Cuba Jamming Ham Radio? Listen For Yourself (IEEE Spectrum)

A public SDR network triangulates the island as the source of mystery signals

By Stephen Cass

As anti-government protests spilled onto the streets in Cuba on July 11, something strange was happening on the airwaves. Amateur radio operators in the United States found that suddenly parts of the popular 40-meter band were being swamped with grating signals. Florida operators reported the signals were loudest there, enough to make communication with hams in Cuba impossible. Other operators in South America, Africa, and Europe also reported hearing the signal, and triangulation software that anyone with a web browser can try placed the source of the signals as emanating from Cuba.

Cuba has a long history of interfering with broadcast signals, with several commercial radio stations in Florida allowed to operate at higher than normal power levels to combat jamming. But these new mystery signals appeared to be intentionally targeting amateur radio transmissions. A few hours after the protest broke out on the 11th, ham Alex Valladares (W7HU) says he was speaking with a Cuban operator on 7.130 megahertz in the 40-meter band, when their conversation was suddenly overwhelmed with interference. “We moved to 7170, and they jam the frequency there,” he says. Valladares gave up for the night, but the following morning, he says, “I realize that they didn’t turn off those jammers. [Then] we went to [7]140 the next day and they put jamming in there.”[]

New school at home of former radio station on track for autumn launch (Coventry Telegraph)

Houlton School, where Rugby Radio Station once stood, is set take its first influx of pupils in September

Plans for a new school at the historic former home of Rugby Radio Station are being fine-tuned and remain on track for a September start.

Houlton School, which will be named after the town in America that received the first transatlantic voice broadcast from Rugby Radio Station in 1927, will take its first influx of 180 Year 7 pupils this autumn.

The school, which forms part of the 6,200-home urban extension in Houlton, east of Rugby town centre, will take a new year group of 180 pupils every 12 months.

Michael McCulley, the school’s Principal Designate, said: “Whilst building a fantastic £39m new school during three lockdowns has had its challenges, we are also acutely aware that we have had a completely blank page from which to develop our exciting curriculum and pastoral programme.

“This freedom has been important as we have needed to evolve to the changing needs of our first group of students.[]

Ham Radio Outlet to open store in Florida (Amateur Radio Newsline)

Ham Radio Outlet, the nationwide amateur radio retailer in the US, has announced that its ongoing expansion plans will include a store in the state of Florida. The new store will join 12 already open in such states as California in the West, where the company is based, to Delaware in the East, Arizona and Texas in the South, New Hampshire in the North. The company’s announcement on social media set off a wave of speculation about the new location, especially on Instagram where the company wrote, “We’re not telling yet! We’re open to suggestions.” The closest Ham Radio Outlet to Florida is in Atlanta, Georgia. The company, which calls itself the world’s largest supplier of amateur radio equipment, is also known for shipping internationally.

Old is gold: In times of satellite & internet, Pune cops keep Morse Code in use as a robust stand-by communication mode (The Indian Express)

Every Sunday, an operator with Pune Police’s wireless wing sends a Morse Code message to the office of the Director General of Police, Maharashtra.

IN THE era of satellite communication, which involves transmitting signals into space and back, and internet based systems transferring gigabytes of data in a flash, police have kept alive the age-old system of Morse Code – a primitive method of sending messages in the form of dots and dashes.

Every Sunday, an operator with Pune Police’s wireless wing sends a Morse Code message to the office of the Director General of Police, Maharashtra. While this is their way of paying tributes to one of the earliest modes of telecommunication, it is primarily a way of maintaining a robust stand-by mode of message delivery in case all other means of communication fail.

Pune City police have recently started a series of tweets featuring the communication systems used by the police and their evolution till date. On Sunday, Pune Police Commissioner Amitabh Gupta tweeted, “As an ode to the beginning of wireless communications, the Commissioner’s Office still uses Morse Code to transmit Messages every Sunday.”[]

Antiques Roadshow: Spy radio disguised as toolbox found in garden shed worth huge sum (The Express)

ANTIQUES ROADSHOW saw a World War II spy radio which was disguised as a toolbox fetch a huge valuation when it travelled to Kenilworth Castle.

Antiques Roadshow’s expert Mark Smith marvelled at the ingenuity of a spy radio which was used in World War Two in a recent episode. The item, from the outside, was made to look like a toolbox but when opened, displayed a detailed radio which could be “powered by any source”. So how much was it worth? Mark put a £10,000 to £15,000 price tag on it.[]

Einstein Listened (WNYC)

Former WNYC director Seymour N. Siegel suggested that WNYC once received fan mail from Einstein. As I continue to look far and wide for evidence of this alleged bit of praise, I can’t help but wonder, what broadcast prompted the great man to write? Alas, so far, the document has eluded me. But, we do know that the father of the theory of relativity was a subscriber to both the WNYC and WQXR program guides. And we have no less than Erwin Panofsky, the noted German-American art historian and friend of Einstein’s, to thank for that.

It all began when the distinguished gang at the Institute for Advanced Study in Princeton, New Jersey decided to chip in and build the Nobel laureate a “high-fidelity” radio for his 70th birthday. The 1949 gift included subscriptions to the WNYC, WQXR, and WABF program guides.[]


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Malahit DSP-2 Review Update: Dan recommends holding off until issues resolved

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:


UPDATE: Malahit DSP-2 (July 24, 2021)

RECOMMENDATION: Hold Off Until Issues Are Resolved

I thought it important enough to write this update to my earlier extensive review of the Malahit DSP-2, the second version of the Russia-made receiver. Earlier incremental updates can be seen on the main article.

In concluding my main review, I spoke about being on the Malahit “train” and “roller coaster” – and my experiences since have shown that to be true.

As noted in one the updates, further testing confirmed the observations of Malahit users that when voltage of a 18650B battery drops below 3.7 v the receiver did indeed shut down. And the battery icon was still showing 50%.

Georgiy at the Malahit team confirmed this as a software bug, and in a test firmware update, the voltage issue was, according to him, corrected. The result, in a test firmware upgrade (2.10) could be seen with remaining voltage displayed in the battery icon itself. But I was unable to confirm that this actually resolved the issue of inaccurate voltage displayed before yet another problem emerged.

After performing the update from 2.0 to 2.10 Test firmware (more on that a bit later)
I thought things were fine until I noticed that all signals had vanished from the Malahit. This applied to the strongest signals from U.S. religious broadcasters, and down through FM.

In a combination of Telegram and Skype chats, Georgiy was extremely helpful – we went over seemingly every possible cause for this problem and focused on the SMA cable which from observing conversations online appears to be an issue in some units.

We went to the point of disconnecting the SMA from the PCB to test if anything brought back any level of signal, which it did not. With my basic knowledge of electronics, I believe that some problem may have developed on the PCB – whether that is directly related to the firmware upgrade process remains unknown.

On the firmware, the Malahit-recommended PC app is SMT32CubeProgrammer, which is easily downloadable, and instructions for the firmware update are on the Malahit You Tube channel. The process and app look difficult at first.

But things get interesting, as they always do, in using these Bootloader apps as I have found on several occasions in trying to upgrade my AFEDRI LAN-IQ.

Instructions on the Malahit You Tube channel direct you to power off the radio, then plug in a micro-USB cable to the receiver and to your PC. The rough Russian translation says push in and hold both main and smaller encoder knobs, and then press power either once or 3 times, and then watch for the LED to go off. The LED actually doesn’t really go off– in the process of the firmware update, flashes on and off.

I managed to get through the process of upgrading – it was quite smooth. The test 2.10 firmware according to Georgiy is supposed to correct the issue with voltage readings, though again I was unable to test this fully because my DSP-2 quite literally went quiet over its entire range.

As of now, and despite the best efforts of Georgiy which I appreciate, I have a dead DSP-2. Whether signal loss was due to some issue with the SMA connector, or whether the firmware process (I reverted back to 2.0 after noticing the signal loss) itself caused something on the PCB to fail, remains unknown.

Given all of this new information, and though I had made no BUY recommendation on my original review, I would have to advise anyone considering a DSP-2 to hold off for a while until the Malahit team is able to thoroughly iron out all the hiccups with the receiver, whether in firmware or hardware. This includes the question of the SMA connector, and the issue of voltage monitoring.

Based on the conversations that were taking place on Telegram, I would also be urging Malahit team to quickly come up with a clear English translation of the Malahit manual, and to review instructions contained in You Tube videos showing the firmware upgrade process.

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Guest Post & Review: Test Driving the Russia-Made Malahit DSP-2

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:


 

Test Driving The Russia-Made Malahit DSP-2

Poised on Edge of Greatness?  (Some Challenges To Overcome)

by Dan Robinson

By now, the Malahit SDR is well known in listening hobby circles.  We have the made-in-Russia original, and those manufactured in China with various firmware and some physical differences such as location of the tuning encoders.

News about the Malahit began to spread in 2019, with articles here on the SWLing Post, including two in February and April of 2020 (https://swling.com/blog/2020/02/the-malahit-dsp-a-potential-holy-grail-portable-sdr/ and one in which the Malahit was put up against an Afedri LAN-IQ SDR (https://swling.com/blog/2020/04/fenu-posts-a-malahit-dsp-afedri-lan-iq-head-to-head-comparison/ ).

At the same time, we saw the development and appearance of the Belarusian Belka SDR.  I consider the latest Belka DX to be the ideal portable – a sensitive diminutive miracle that has become a must-have device for many of us.

As for the Afedri LAN-IQ, I held off on purchasing one until the “Standalone” version was available.  It is made in Israel by a Russian developer who supports the receiver with fairly frequent firmware revisions (though upgrading remains a bit of a challenge involving some obscure boot-loading software).

I waited and observed reviews of the original versions of the Malahit.  When its designer, Georgiy (RX9CIM), announced availability of the new DSP-2 version of the receiver, with expanded coverage to 2 GHz and a claim of improved performance, I finally purchased one.

As was observed in one of the early SWLing Post articles “It seem[ed] the project is open source, the schematic, PCB and software are available to download. . . we hope [these] receivers become popular and available world wide [and that] this new project “shakes” a bit the industry of shortwave receivers.”

Malahit project authors RX9CIM George, R6DAN Vladimir, and R6DCY Vadim, had the apparent objective of “designing a low-cost portable SDR radio, using only easily obtainable components and to become the natural successor of the popular Degen and Tecsun radios.”

At the time, the price for a finished Malahit, with an ARM chip at its center was about $195 US.  Coverage was to 1 GHz – this has since been extended to 2 GHz.  Synchronous AM mode was added, and the DSP-2 also comes with an internal battery tray for a single 18650 Li-on battery.

This is a change from the original flat Li-on cell, and in my opinion a welcome one  since 18650s are easily obtainable.  Being able to easily change out a battery is important, rather than messing around with soldering (the famous Reuter Pocket receiver made in Germany should take a hint).

In this age of the SDR, we’re all familiar with the SDRplay series and various AirSpy receivers, along with other SDRs such as the RX666/888.  Before that, we had the famous Perseus, which still has a strong following, and numerous WinRadio receivers.

See the articles here on the SWLing Post assessing the performance of these, as well as reviews at eHam.net, and numerous SDR dongles all over eBay, coming from China.  There is also an SDR group on Groups.io.

Of course, receivers and transceivers with panoramic displays began to appear some years ago – the ICOM IC-R8600 and IC-7300 are examples of how this technology was integrated into the listening and amateur radio markets.

What we had not seen was integration of this kind of technology into portables.  Even in its latest iteration, the Belka DX has a small screen without any PAN display.  So, the advent of the Malahit has made this kind of advanced display widely available.

The price, by the way, for my DSP-2 as of July 2021 was 19,500 Russian rubles, with an extra 2,000 rubles for express delivery via Russian Post (though due to COVID Georgiy stressed that no guarantees could be made as to timing).  That’s $263 – not a small investment and rivaling the cost of a Tecsun ATS-909x and H-501x.

According to the description I received when ordering, the Malahit DSP-2 was improved over the previous version with the following differences:

  • Frequency range – from 50 kHz to 380 MHz, and 400 MHz to 2 GHz
  • Improved RF shielding and hardware improvements to reduce interference
  • Changes in software functions
  • Dimensions changed to 140x 88x 39mm
  • 18650 battery

The DSP-2 is in a thin black metal cabinet with dimensions 5 x ½ by 3 x ½ by 1 x ½.

A power button and headphone jack are on the right along with a power LED.  On the top, we find the SMA antenna input, and a small telescopic whip is included.

The speaker, capable of some decent audio, is located on the inside rear of the receiver – audio level exceeds that of the Belka DX with its very small speaker, but the Belka has a clarity that often exceeds the Malahit.

My first testing of the DSP-2 was indoors, in a far corner on the top floor of my home, using just the included whip antenna.   For comparisons, I used a Tecsun PL-368 with its whip antenna and a Belka DX in the same location.  I find that indoor testing tends to identify some issues that would not be apparent outdoors.

In this, the Tecsun PL-368 and other Tecsun portables consistently performed best, followed by the Belka DX and the Malahit.  This may be surprising, but shows that radios specifically designed for shortwave reception, often provide better reception because they are matched better with their internal telescopic antennas.

Now, when I say “best” I mean best basic audio quality, using auto-memory and ETM functions on the PL-368 and 990x.  But what those radios can do with the signal after that point is pretty limited – there is no NR (noise reduction), you’re limited to a handful of set bandwidth selections, and SYNC mode leaves much to be desired.

Which is where the Malahit comes in with its numerous levels of flexibility, accessed through MENU icons on the lower part of the screen:  HARD, AUDIO, VISUAL, NR, MODE, and BAND.  I refer the reader to the Malahitteam site links showing the user manual (this is still a bit in the rough, with translation from Russian) and another link with a Quick Start guide written by John Pitz (KD8CIV).

KEY HIGH POINTS ON MALAHIT

SUPERIOR COLOR DISPLAY

The color display, also seen on numerous China-made clones, is the best on any handheld SDR.  Where the Belka LCD is a basic utilitarian tool that performs well for that receiver, the Malahit display is an invitation to the wonderland of what this receiver offers.

At the top are small icons for:  SQ, NB, NR, AGC, ANT, PRE, MODE.  Right of center, and controlled with pushes of the small volume encoder knob, are ATT, VOL, FILTER, and the battery icon.  Below those are headphone and speaker icons and an excellent, if small, frequency window.  Pushing the small encoder knob selects/controls volume, attenuation, and main filters.  The large tuning knob, with a press, selects step increments.

EXCELLENT NOISE REDUCTION

Noise reduction on the Malahit is superb, as many users have observed.  It’s activated directly with a front panel icon and Threshold is adjustable with an icon under AUDIO, with 0 to 30 increments.  NR is so good that I compare it with the latest firmware version on the ICOM IC-R8600 – it’s actually probably better than the ICOM even near and at the highest 30 level.

EXCELLENT FILTERING

Whereas the Belka DX offers fixed audio filtering values accessible via its front panel, the Malahit DSP-2 offers continually variable LOW FREQUENCY adjustment from 0 Hz to 2350 Hz, and HIGH FREQUENCY adjustment from 100 Hz all the way up to 150,000 Hz.   This is in addition to standard NARROW, NORMAL, and WIDE filter options selectable with the volume encoder knob.  This is nothing short of extraordinary for a handheld portable receiver.

The latest (and possibly last) Tecsun receivers offer set value multiple bandwidths, which is excellent but is a throwback to radio design from years ago.  So, the DSP-2 capabilities can be compared to the kind of filtering that a Watkins Johnson or Cubic receiver have, but in the palm of your hand.

As I often observe, what we would have given in gold to have this kind of capability in consumer receivers during the glory days of international broadcasting!

AGC / MGC FLEXIBILITY

The Malahit allows the listener to use AGC, with choices of SLOW, MEDIUM, and FAST.  But it also allows, again through the AUDIO settings menu, control of AGC GAIN 0 to 60, and AGC LIMITER 40 to 90 db.  Wow – priceless!  So even if you prefer, as I do, to listen to shortwave using AGC, you still have amazing flexibility.  You can still switch to MGC with 0 to 60 range.

NOISE BLANKER FLEXIBILITY

Just as the Malahit delivers on AGC, so does it deliver with its regular noise blanker function.  With NB activated, there are 3 configurations with a separate THRESHOLD icon adjustable for each of these.  Amazing.

RF GAIN FLEXIBILITY

RF GAIN is adjustable from 0 to 59, and there is a separate icon for adjusting gain for the PRE-AMPLIFIER.  Where the PREAMP comes in very handy is when one has the Malahit indoors – it provides a more sensitivity in situations where one is using the telescopic whip antenna, though care must still be taken not to overload the receiver and distort signals.

FCORRECT FUNCTION MAKES FOR EASY RE-CALIBRATION

The Fcorrect function located under the HARD settings menu enables one to re-calibrate the receiver to correct for error.  This is similar to the capability that Tecsun added to its 330, 909x and 501x receivers (there are indications Tecsun has or will enable this ability also in the PL-368) but seems, based on my testing of the Malahit to be more effective.  After I corrected my DSP-2 to about +57, calibration was pretty much on the money up and down the HF bands.

SQUELCH FLEXIBLITY

The Malahit not only has SQUELCH, but SQUELCH THRESHOLD control, another example of the tremendous flexibility in this receiver’s firmware.  Since I do not do much listening outside of the HF bands, or have the antenna for it, I have not extensively tested the Squelch above 30 MHz and up to the maximum range at 2 GHz.

There is yet another feature described as adaptive noise canceling that allows the user to significantly improve the intelligibility of the received station under conditions noise and interference.

[From the manual]:  The squelch uses different algorithms [depending] on filter bandwidth.  With a bandwidth of more than 1 kHz, a squelch of more than suitable for speech type signal.  With bandwidth less than or equal to 1 kHz, the squelch is suitable for tone type signals.  Choice of algorithm is carried out automatically, depending on bandwidth.  Meanwhile, squelch for speech signals can be used with NR (see further details on this in the manual).

FM RECEPTION WITH RDS

What the Belka DX lacks, namely reception of the FM range, the Malahit delivers in droves.  FM sounds excellent to me, on the same level perhaps of the Afedri LAN-IQ Standalone receiver.

RDS is enabled by touching the waterfall area of the display which brings up the RDS information.  The speed with which station information appears varies depends on position of your antenna and signal level.

As one user (Harold Hermanns) on the Facebook Malahit group observed:  “ I don’t think it works very well. I just checked mine, and went to about 25 stations. The RDS or station name came up on only 5 stations. Letters I get are PS, PT, and PTY. When you tune a strong station, give it a minute or so, that’s what I did, and the RDS feature does work, but again, it’s not 100%.  Maybe will be improved with firmware?”

The RDS information could be better organized – currently the name of the station, and name of the program scrolls on different lines.  Another touch of the screen brings up an old style FM scale – this is nice, but I prefer the PAN display.  Yet another touch returns the screen to the PAN display and waterfall.  Mode options include NFM and WFM, and another option provides FM-STEREO.  Also in FM, there is an auto-search function and station labeling

MISCELLANEOUS FEATURES

There are some other features in the mind-boggling list of options in various menus:

  • In FM (WFM) there is an eight position EQUALIZER function with SOFT, LIVE, CLUB, ROCK, BASS, JAZZ, POP, and VOICE positions.
  • A voltage monitoring function allows the user to turn off the receiver when voltage drops lower than 3.3 volts.  As explained in the manual this is intended to preserve battery life and avoid full discharge.
  • Antenna selection can be 50 ohms or Hi-Z (preferred for telescopic antenna use).
  • As the Malahit manual details, internal gain of the receiving chip can be adjusted.  Accessed from the HARD menu, this is too much for me to go into here, but it’s another example of the detail that went into designing the Malahit.
  • Brightness of the display backlight is adjustable as well as time after which backlight level is reduced to minimum and turned off completely.  Rate of change of the display spectrum is adjustable as is spectrum display range, color, ratio of waterfall and speed and brightness of waterfall.  Spectrum scale and view are adjustable.
  • There is a 5 page memory system, with M1 to M10 in each, so a total of 50 storable memories.

LOW POINTS OF THE MALAHIT

NOISE FROM THE DISPLAY

Example of noise on 1,000 kHz

As I was testing my Malahit DSP-2 it quickly became clear that there is one major low point, and thus a challenge for Georgiy and other members of the design team.

There’s no other way to say this:  internally-generated noise remains the major issue keeping the Malahit from achieving greatness.

 

The developers of the Russian version receiver have not attempted to hide this, and users noticed it from the beginning, with one writer identifying “internally generated noise, which peaks at various frequencies” as one of the key drawbacks of the Malahit.

I had hopes that the DSP-2 version of the Russian-originated Malahit might have less of this problem.  There are numerous internally-generated noise/buzzing spikes, some stronger than others, by my estimation at intervals between 125 and 200 kHz throughout the HF bands.

Example of noise on 6,000 kHz (RHC)

In the case of one huge noise spike appearing at or around 6,000 kHz – right over Radio Havana – it ruins any chance of hearing clear signals at, below and above that point.  As you can see in my video, the Belka DX does not have this problem (note: apologies for mis-spelling Malahit as Malachit).

VIDEO: Malahit With Display Generated Noise

Click here to view on YouTube.

Via Telegram, Georgiy asserted to me that when using an external antenna, noise is not as serious, and notes differences between the Malahit and Belka.  The Belka, he says, is a simpler device that concentrates only on shortwave, while Malahit is a wide band receiver with more complex DSP and user functions.

“When Belka cannot receive something, Malahit can.  And where Belka does not have noise, Malahit has it.  These devices are in different classes.”

The result is that a major workaround is often necessary – to disable the VIEW PAN&WTF option, a key feature that is a major highlight of the radio.

Georgiy says that this problem is mainly linked to telescopic antenna antenna operation because of the antenna’s proximity to the display.  But as you can see in my video, when testing the Malahit and Belka on 6,000 kHz it’s a night and day situation.

A quick push of the power button blanks out the display completely – and seems to completely resolve the noise issue.  But you don’t buy a radio to see a dark display, and it’s depressing to think that turning off a major feature, namely panoramic display, has to be part of standard operating procedure.

When testing the Malahit from its bottom frequency of 50 kHz, even with the PAN & WTF off, huge buzzing noise spikes are heard.  In mediumwave/AM, they are seen at  615 kHz, 790 kHz, 965 kHz, 1140 kHz and so on.

If a radio had emerged from a known large manufacturer with this issue, such as Tecsun or Sangean, it would have been roundly condemned by users and reviewers and sent back to the drawing board.

Georgiy does say that in the new firmware interference from the display was decreased, with a “step of about 2.5 MHz, from 1MHz (i.e. 1MHz, 3.5MHz, 6MHz).  After correction it will be with a step [of] 4 MHz”.  I’m not quite sure what he’s saying with this, due to language issues, but the overall indication is that he is aware of  this issue and will continue trying to tackle it in future revisions.

CW DECODING

In the MODE section of the Malahit there is no confirmation that the receiver is actually in CW.  Decoding is enabled with an icon, but again no confirming icon at the top of the display.  This is a bit odd.

Going to the Telegram app discussion group for the Malahit, and re-reading the translated Russian manual, I discovered that confirmation of CW appears as a white bar under the SPEAKER/HEADPHONE icon on the right.  There is also a MINIMUM SNR option in decoding, with a 0 to 70 range.

A You Tube video (the Gerry DX channel) shows the decoding process and notes that it’s important to keep the filter setting at NARROW when attempting to use the decoding feature on the Malahit and also important to set the SNR at the right level.

One would think that this could be easily rectified, but adding a CW indicator to the top row of small icons on the front display might not be as easy as one thinks, unless the display can be modified to also display “CW” in the icon spaces for AM, LSB, or USB.

It turns out that CW decoding on the Malahit works quite well, at least in my attempts.  I was able to decode fairly strong CW signals in 40 meters.

LCD/TOUCH SENSITIVITY

When I first got the Malahit, I was puzzled by what seemed to be a serious lack of sensitivity on the display when trying to use the touch icons to change configurations and modes.

This was so bothersome that I raised it with Georgiy who responded that this is by design.  The present capacitive touch method, he says, is preferable and more comfortable for users.   “If [we were to] change the touch [enable faster response] then [some] people will demand to decrease it.”

With benefit of some time, I have concluded that a slightly firmer and longer press of about half a second to a second almost always brings up the menu selected.  But this is definitely a characteristic of the DSP-2, so potential owners should be aware of it.

ISSUE WITH CLOCK

Another issue that prospective purchasers should be aware of involves instances where the internal clock of the receiver does not retain the time, and the solution for this directly from Georgiy is not necessarily satisfactory.

“Yes, they need to be removed from the PCB” he says, a reference to two capacitors on the main PCB, C29 and C30 which are next to each other below a larger M7 device on the PCB.

These are SMDs so anyone without good soldering skills will be hard pressed to want to mess around with that PCB.  This is not a confidence-builder, nor a solution – clearly these receivers should come from the supplier without such an issue.

This was upsetting enough for some users that the Malahit team faced some sharp criticisms.  One user said the clock on his DSP-2 was working perfectly.  Another said: “Unless I power off the unit the date stays good but the time is always 2 hrs and 10 minutes behind. As soon as I power off the unit the date defaults back to 15:08:2062.”

One user said:  “Problem is voltage is very inaccurate causing the clock settings to be lost. I have tried several 18650 batteries (good Panasonics) and fully charged they are 4.2v, but the DSP-2 indicates 4.6v. When the battery runs down to 4.0v the clock settings are lost. Also, the battery indicator continues to show FULL. I think there is an internal problem with the DSP2. Perhaps the new design, or new internal parts are causing this. This is very disconcerting.”

In exchanges on Telegram, Georgiy said he personally checks each outgoing Malahit for sensitivity on each band, and clock operation, among other things.  In a later comment just before this article went to press, Georgiy said that C29/C30 should be replaced only if there is a problem with the clock.

There is no mention by the Malahit team of any official return policy – which of course would be quite challenging and costly involving an additional round trip for a receiver back to Russia and then back again to the user.

On my DSP-2, which I have used with an Anker 26800 USB battery, so far my clock/date settings have maintained accuracy with no reset, even after the USB cable is unplugged from the receiver.  I have not yet tested longer times to see if the clock/date is reset when voltage drops below a certain point.

[UPDATE: 22 July 2021]

In a message sent after publication, Georgiy says that the C29 and C30 capacitors will be deleted from the next series of the Malahit, and for now they are being removed from receivers that have not been sold yet.

[UPDATE 23 July 2021]

Further testing revealed that the observations of Malahit users are accurate. When voltage of a 18650B battery in my Malahit dropped below 3.7 v the receiver did indeed shut down — this is with the battery icon still showing 50%. So this is definitely an issue that needs to be addressed in future updates. That said, I got hours of operating time before the full 18650 dropped to the cutoff level — but obviously an inaccurate battery icon is something that the Malahit team will have to correct.

THE BATTERY GAME

Example of 18650 rechargeable batteries

The Malahit DSP-2 uses a 18650 Li-on battery.  Unfamiliar to many people, these are actually well known among professional-grade flashlight collectors/users (flashlight collecting is another of my vices).

One of the first things I realized when my Malahit arrived was that my existing button top 18650 cells were too long to comfortably fit in the battery tray.  A bit of research on the Facebook Malahit group page revealed that some users have modified the receiver to take two 18650 cells, with a double tray replacing the single tray.

The original Malahit tray requires shorter “unprotected” flat top 18650 cells.  At the time I write this, there is a shortage of these cells at the major battery / flashlight suppliers (Battery Junction is one).  DO NOT try to force a slightly larger 18650 in the stock Malahit battery tray!

So, one recommendation I would make to the Malahit Team in Russia would be to make it possible for the receiver to use regular protected button top 18650s, of the type one would easily use in a Tecsun receiver such as the 909x and H-501x.

However, in a message to me just before this article went to press, Georgiy said that the Malahit team has used “typical holders” available to them and that they had been unable to obtain a sufficient number of alternative trays for protected 18650 button top batteries.  So, for now at least the Malahit will require unprotected flat tops.

My 18650B flat top batteries arrived just as I was completing this review – easily charged up in my Littokala charger, each then fit easily in the single battery tray and power the Malahit perfectly.

ENCODER KNOBS

Higher quality replacement knobs

The original encoder knobs on the Malahit can be replaced by higher quality, metal construction ones for the small and larger knobs.  I got mine from Nikolay, a member in Russia of the Malahit Facebook group (he says he sources them from Switzerland, but I have not confirmed this).

I am, however, not sure that the new knobs can simply be installed on the Malahit – there are no set screws on the original plastic Malahit knobs and I chose not to mess around to see whether the metal knobs can easily be installed, at least for now.  Price for the higher quality metal knobs:  $17

[UPDATE 23 July 2021]

Nikolay Vedeneev in Russia produces high quality encoder knobs for the Malahit, Afedri, and Belka SDR receivers. He can be reached at: nickstrannik@gmail.com and received a very positive review from Fernando Duarte who is known for his reviews of numerous receivers. Both of his knobs fit perfectly on the shafts of my Malahit DSP-2 and have a much better feel than the originals (NOTE: I used a 1.5 mm hex key to tighten the set screws) https://fenuradio.blogspot.com/2020/07/custom-tuning-knopfe-fur-jedes-gerat.html

VIDEO

Click here to view on YouTube.

POISED ON THE EDGE OF GREATNESS

The subtitle of this article asks whether the Malahit is poised on the edge of greatness.  I believe it is, but anyone’s choice to join the Malahit user/fan club comes with some headaches.

We can only hope that the Malahit team can work on the problem of noise spikes that permeate the lower frequency ranges from mediumwave on up.  There’s no way to minimize this:  at $263 (the price of a DSP-2 as of July 2021) buyers should not have to be shutting off the display to eliminate noise.

As for the question of the clock on the DSP-2 not maintaining time/date, etc it’s clear that Georgiy and the Malahit team are aware of this issue and one hopes this could be checked off the list of concerns that users have raised.

Whether one needs all the bells and whistles that a Malahit offers is the major question, especially when the Belka DX offers excellent stepped (not continuously adjustable) audio filtering and a form of synchronous AM detection in what has to be the smallest high performance receiver ever available to the listener.

More than a few Malahit owners have observed that between 1.5 MHz and 30 MHz the Belka DX seems to be the better shortwave receiver, with no display noise issues, superb battery life and an amazing small size that makes it the ultimate ultra-portable.

In short, if you choose to step aboard the Malahit train you enter a world where there will be constant improvements in software and hardware, and bugs along the way, of which noise spikes issue is a perfect example.  But if you’re someone who gets enjoyment from being on the leading edge of technology in radio development, the Malahit may be for you.

It’s impressive that the Malahit originated in Russia, not generally been known for innovations at this level.  In recent years, Asia was the main source of advances from the likes of ICOM, Yaesu, AOR etc in the amateur radio area, and from Tecsun, Sangean, and Eton in the area of portable receivers for HF listeners.

Finally, one has to wonder about the potential that the Malahit design holds for integration into the kind of portables seen over the past two years.  Some observers have asked why the LCD display and other features on the Malahit could not be part of a future receiver that looks like a Tecsun 990x or Sangean 909×2 with additional advances such as off-air microSD recording, and DRM.

FINAL ASSESSMENT:  I boarded the Malahit bus fairly late, but I am definitely a fan.  Owning one of these receivers is indeed a roller coaster – anyone climbing on should become a member of the Facebook and other discussion groups where users exchange views, suggestions, and their own experiences.

For ultimate portability in 2021, the Belka DX wins the race.  But the Malahit wins on the sheer number of advanced signal processing and other features it contains, though it is hobbled to an extent by the problem of display interference.

If Georgiy and the Malahit team can continue to make steady progress in confronting the noise issue and fine tune the already amazing array of features, the Russia-made Malahit has a bright future ahead.

[UPDATE 24 July 2021]

In the latest firmware update to the Malahit DSP-2, Georgiy provides this
changelog. Note that this is still described as “TEST” firmware, so it’s still unclear
whether he intends to put out a non-TEST version of this particular upgrade:

Firmware 2.10 TEST:

  • fixed battery voltage indication
  • fixed behavior of encoder buttons at low supply voltage
  • protection against false switching has been made – for switching on by three, set switch 2 to the On position.
  • added test function – increased display frequency. This reduces noise and increases the number of frames per second; To enable this function, set switch 3 to On. The function may not work correctly, if so, please let me know
  • the level of interference from the display is slightly reduced
  • changed the distribution of frequencies to which the input high-pass filters are turned on
  • when HiZ is turned on, the power supply of the external active antenna is automatically turned off;
  • added indication of external antenna power on – now the ANT indicator is highlighted in red if this function is enabled
  • the algorithm for displaying the picture on the display, slightly reduces the level of interference
  • changed the panorama display mode from “Pan & WTF Disabled / Enabled” to “Pan & WTF Single / Always”, while the panorama image is now always present, but it is updated once (when the settings are changed) or always.
  • fixed attenuators bugs

[UPDATE 2, 24 July 2021 ]

Please read this updated post explaining why I believe you should hold off on making the DSP-2 purchase until software and hardware issues have been resolved.

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Radio Waves: Keeping CA Wildfires at Bay, 50 Years of KNOM, 24-Hour Saudi Radio Urdu Service, New Comms for Navy Subs, and North Korea Cracks Down on TV

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Peter Abzug, David Iurescia, and Dan Robinson for the following tips:


How A Group Of Dedicated Volunteers Are Keeping California’s Wildfires At Bay (NPR)

The Los Angeles Fire Department depends on help from amateur radio volunteers when fire threatens communications infrastructure. NPR looks at how ham radio operators are keeping residents safe.

50 years of KNOM Radio Mission (KNOM)

Whether you’ve been with us since the beginning, or you’re just getting to know us: it’s you, and your faithful support, that has made KNOM America’s oldest Catholic radio station. Thank you!

KNOM has been broadcasting in Western Alaska since July 14th, 1971, when the station could first be heard in Western Alaska.

The continuing mission has been possible only by the hard work, sacrifice, dedication, and love of thousands of people: our staff and volunteers, listeners and community members, and thousands of loyal benefactors across the nation who keep the lights on and the transmitters running. KNOM stands on their shoulders.

[…]Fifty years into KNOM’s history, the radio station is deeply embedded in Western Alaska. As we look to the future, KNOM’s vision is to one day be ‘taken over’ by the region – existing entirely for, and by, Western Alaskans. As the very first song ever played on KNOM – “We’ve Only Just Begun”, by The Carpenters – proclaims, the mission is just getting started.

KNOM continues to live out its values each day – as it has for five decades – as a friend and companion offering respectful service based on Catholic ideals. It is centered on the four cornerstones of the mission: Encountering Christ, Embracing Culture, Empowering Growth, and Engaging the Listener.

KNOM continues in sharing God’s love for Western Alaska through embracing its strength and beauty and being invested, long-term, in the growth of the region.

By engaging each listener with respect and companionship, KNOM hopes to amplify stories of hope, courage, and resiliency in Western Alaska.

Click here for stories and features on the KNOM 50th Anniversary Page. 

Saudi Radio To Launch 24-Hour Urdu Transmission (Bol News)

JEDDAH: The Saudi Radio plans to launch test transmission of a 24-hour Urdu service from the middle of September 2021, while the services will be formally launched on September 23, a Saudi official said.

The transmission will include programmes on Islam, the holy Quran, Ahadis and historical and world affairs.

Saudi Broadcasting Authority deputy chairman Faisal Ilyafi said this, while talking to a delegation of the Pakistan Journalists Forum (PJF).

The world transmission was started from the holy city of Makkah in September 1950 with a 15-minute slot for the Urdu programme, he said, and stressed that it is the need of the hour to face challenges and keep ourselves abreast of the changes in media.

The Saudi Urdu transmission has decided to continue its transmission on social media, such as Instagram, Facebook, YouTube, FM, Shortwave, Satellite, and Twitter, he added.

Saudi Crown Prince Mohammed bin Salman has given approval to the project under the supervision of Media Minister Dr Majid bin Abdullah Al Qasabi, he said, adding that the Saudi Information Ministry has also made several other languages part of the project.

The deputy chairman said any language has a supreme significance to disseminate news-cum-events, that’s why many foreign languages such as Russian, Spanish, Japanese, Hebrew and Chinese would be part of the transmission.[]

Communication Breakdown: Navy Submarines Need a New Way to Talk to Each Other (The National Interest)

Sea water diminishes the power of electrical transmission, challenges identified many years ago by the Navy and some of its partners who have been working on under communication for decades such as Northrop Grumman.

As Navy innovators work intensely to pioneer new methods of undersea communication, many might wish to reflect upon the decades of technical challenges associated with bringing any kind of undersea real-time connectivity to submarine operations. Historically, certain kinds of low-frequency radio have enabled limited degrees of slow, more general kinds of communication, yet by and large submarines have had to surface to at least periscope depth to achieve any kind of substantial connectivity.

The advent of new kinds of transport layer communications, coupled with emerging technologies woven into unmanned systems, are beginning to introduce potential new avenues of data processing and transmission intended to bring greater degrees of real-time undersea data transmission to fruition.

Sea water diminishes the power of electrical transmission, challenges identified many years ago by the Navy and some of its partners who have been working on under communication for decades such as Northrop Grumman. Northrop’s efforts date back to the World War II era and, along with the Navy and other industry contributors, helped pioneer the innovations that helped adapt RF communications architecture to sonar today. Considering this history, there are some interesting synergies woven through various elements of undersea warfare radio communications.

A 2014 essay by Carlos Altgelt, titled “The World’s Largest “Radio” Station,” details some of the historic elements of how the U.S. Navy pursued Extremely Low Frequency (ELF) undersea connectivity. Through its discussion of low-frequency ELF connectivity, the essay explains the technical challenges associated with undersea communication, which seem to align with how Northrop Grumman innovators describe how undersea communications will need to largely evolve in the areas of acoustics and optics.

As Altgelt notes: “As a result of the high electrical conductivity of sea water, signals are attenuated rapidly as they propagate downward through it. In effect, sea water ‘hides’ the submarine from detection while simultaneously preventing it from communicating with the outside world through conventional high-frequency radio transmissions. In order to receive these, a submarine must travel at slow speed and be near the surface, unfortunately, both of these situations make a submarine more susceptible to enemy detection.”[]

North Korean capital cracks down on illegal TVs to prevent access to South Korean broadcasts (RFA via the Southgate ARC)

Each Pyongyang household must report the number of TVs they own, and they face stiff punishments for hiding them

North Korea has ordered residents of the capital Pyongang to report the number of televisions in each household to stop them from watching banned shows from prosperous, democratic South Korea, sources in the country told RFA.

In North Korea, access to media from the outside world is strictly controlled, and TVs and radios are manufactured to only pick up domestic channels and must be registered with the authorities. But residents do find ways to access South Korean signals, either by using foreign televisions or modifying domestic ones.

Getting caught during routine inspections with a TV that can pick up illegal signals is a punishable offense. Residents with more than one television hide their illegal TVs during inspections, only to bring them out again to watch Seoul’s latest hot drama or variety show, former residents told RFA.

Authorities are aware of the deception and have issued a directive that every household in the city declare to their local neighborhood watch unit how many televisions they have.

“Residents are trying to hide them, but the judicial authorities are trying to find them. They are looking for TVs that can get South Korean TV channels in addition to the ‘official’ channels,” said a resident of Pyongyang, who requested anonymity for security reasons.

“Everyone knows that in Pyongyang, South Korean TV signals can be picked up in various areas,” the source said. He mentioned the Mangyongdae and Rangrang districts in the center of the city of 2.8 million.

In these areas the residents have been known to have two or three televisions in their homes, so they can watch the legal channels during inspections and watch South Korean broadcasts in secret,” the source said.

The source said that residents have developed clever ways to hide their illegal TVs.

Read more from this very interesting Radio Free Asia article:
https://www.rfa.org/english/news/korea/tv-05252021155129.html


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Dan Notes: Vintage JRC Receivers Set Price Records in Japan

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:


Vintage JRC Receivers in Japan Set Price Records

by Dan Robinson

While used market prices for older vintage communications receivers have been dropping significantly in recent years, prices for some classic “premium” receivers — particularly rare marine radios made by Japan Radio Company — have remained in the stratosphere.

The past year has seen a number of examples of this observable on the Japan Yahoo auction site Buyee, and in May and June of 2021 two JRC sets sold for more than $5,000 dollars each after intense bidding.

Both of these involved what appeared from photos to be mostly pristine NRD-240 receivers which came complete with original manuals and cables.

Photos

With Serial Numbers of 66149 and 50337, manufactured in 1996 and 1997, these receivers are examples of what I call “time capsules.” Their condition indicates that they were both in the hands of collectors in Japan, and probably were not in regular extended service as shipboard receivers.

The first sold for $5,776.06 after 164 bids on the Buyee site, while the second went for $5,166.72 after 77 bids.

As described here in an old Universal Radio ad, the JRC NRD-240 was built for marine operations and complied with GMDSS requirements. With coverage from 90.000 to 29999.999 kHz it has 1 Hz display in LSB, USB, AM, CW, and FSK (RTTY) modes. Like many JRC marine receivers it had a front panel selectable 2182 kHz emergency channel. Bandwidths include: 6, 3, 1 and 0.3 kHz with 100 channels, scan/sweep, along with a switchable AF Filter, NB, Lock, Keypad entry, built in speaker, Squelch, BITE, Dimmer and AGC selection.

In the lineup of the most sought after JRC marine receivers, the NRD-240 is listed in the famous guide book by Fred Osterman “Shortwave Receivers Past & Present” on Page 222, as well as on the cover of the book. The price tag is $8000. The receiver was also the subject of a review by in the former Passport to World Band Radio in 1991.

Historically, the NRD-240 was replaced by the JRC NRD-301A, which itself was later replaced by the super-rare NRD-302A, and still later the NRD-630. In terms of rarity, at this point based on my following of the premium receiver used market, the most rare of the JRC marine sets are the NRD-95, followed by the NRD-630 and 301 series.

When bidding gets furious for radios like this, it can take one’s breath away and that was certainly the case with these two NRD-240s. How many more like these, in this condition, may remain in the hands of collectors is, of course, not known.

The rarity of certain receivers can be measured also by the number of user videos showing up on You Tube. There are many of the NRD-92/93 receivers, even some of the NRD-630, and a few showing much older JRC sets such as the NRD-73. I have yet to find a video showing a NRD-240 in operation.

The Japan Buyee site (which sometimes also has receivers that are not physically located in Japan) has a seemingly constant flow of these amazing vintage JRC sets, along with other premium rigs. Photos of the two NRD-240s that sold in May and June are posted with this article (above).

Click here to check out listings on Buyee.

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Guest Post: Great news from CFVP Alberta!

Many thanks to SWLing Post contributor, Dan Robinson, who shares the following guest post:


Big news in these days of declined shortwave

by Dan Robinson

It is rare — no super rare — that we get any good news these days about shortwave broadcasting. Remember the excitement a few years ago when Guinea returned to shortwave? Then, Nigeria returned but has now become worryingly intermittent.

Today, a station returned to shortwave, one that was absent for some time.

CFVP, the low power relay of 1060 kHz AM in Calgary, Alberta returned to 6,030 kHz with the help of amateur radio operators. The station had been off the air through 2019 — the last time it was reported was in late 2018 when it was relaying CKMX 1060 AM in Calgary.

According to a note posted on the World of Radio group:

“two engineers from Bell Media, Dale and Gerry, who are also hams, VA6AD and V6QCT respectively, rebuilt the transmitter (partially with ham radio parts) and repaired the connection to the antenna with a temporary matching network…the temporary matching network means that not all the 100 watts are going into antenna.”

According to Harold Sellers, who is acting as eQSL manager for the re-activated shortwave station, CFVP 6030 was back on the air as of 0900, though I was unable to hear it until later on June 19th. Best reception was via SDR sites in southern Alberta, northern Montana, Idaho and up in Edmonton, Alberta.

Programming consisted of straight comedy routines from Funny 1060 AM, the Calgary station that carries old recordings of standup comedians, with local IDs and ads mixed in every few minutes. I made a video showing CFVP reception on one of the SDR sites, changing between 6,030 kHz and 1060 kHz which was also audible at SDR locations.

Earlier this year, in March, DX’er Don Moman reported the following, which proved to be true:

” . . .They had a transmitter problem which has been fixed, but they have also identified an antenna issue. The problem [was] troubleshooting and testing the antenna and matching network in the point blank presence of a 50kw AM transmitter. Testing/ repair on CFVP radiator will be done when the 50kw signal can be powered down or off, to enable more accurate testing. Bell will not power down or shut down during ratings periods which are long and frequent. Having said that, repair will likely happen with the above taken into consideration, as well as warm weather. Best guess: Before next winter at the latest, this spring the earliest.”

In August, Harold Sellers reported that the ground at the base of the shortwave tower was under water, and that grounding rods and ground wire needed replacement, and later that the tower grounding had been replaced/fixed. The transmitter also had issues but was repaired and back out at the site.

I quickly sent a reception report to the email address provided by Harold Sellers, and was pleased to receive back a eQSL which Harold said was the second one sent out to those who heard the station on its re-activation day.

Those of us who began our listening in the 1960’s (some much earlier than that!) remember the great days when Canada had a number of regional stations on shortwave. QSLs from some of those, including a 1983 QSL from CFVP/Calgary, are attached to this article.

A screenshot of CFVP as it was being heard on reactivated 6,030 kHz is also shown.

Interestingly, the Wikipedia listing for CKMX shows 6,030 kHz as being active — it’s not known, however, whether the Wikipedia listing was ever updated to note that 6,030 kHz was off the air for nearly 2 years.

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Dan reviews latest firmware version of the Tecsun PL-368 and shares list of hidden features

Many thanks to SWLing Post contributor, Dan Robinson, who shares the following guest post:


Revisiting the Tecsun PL-368:  Assessing a Later Firmware Unit

by Dan Robinson

This past April, I reviewed Tecsun’s PL-368, the update of the PL-365 (also sold by CountyComm as the GP5).  There were some major changes:  Tecsun shifted from AA batteries to a flat BL-5C cellphone type battery, and of course the marquee design change was the addition of a keypad.

The keypad is a night and day change – whereas before the PL-365 was a handy receiver but hobbled by archaic tuning limited to memory access and the side thumb wheel, the 368 provides easy instant frequency selection.

In my previous review, I mentioned the well-known characteristic of the 360 and 365 models which exhibited over-sensitivity to the touch.  When removing your hand, signal levels plummeted – usually, a full grip was necessary and any variation caused reduced sensitivity – noticed mostly in shortwave mode.

The PL-368 I reviewed was from among the first versions of the receiver.  It had a firmware of 3681, from a 2020 production run.  Recently, I received from Anon-Co – the most reliable supplier of Tecsun receivers – an updated unit, with firmware 3684.

Please see my previous review for comments on various aspects of the 368: the longer but less robust telescopic antenna, addition of detents on the volume wheel, and the welcome addition of adjustable bandwidths, synchronous detection, and ability to tune in 10 hz increments, and other changes.

PROBLEMS

SYNCHRONOUS DETECTION:  As with the 909x and H-501, the upgraded 368 now has Synchronous Detection.  I did not expect any change in the 3684 firmware – SYNC still has some distortion and loss of lock.

As with the 330, 990x, and 501x successful use of this mode requires a delicate dance involving careful selection of various bandwidths while in SYNC mode and fine tuning.

However, whereas on the previous 3681 unit there was significant “warbling” when in SSB and SYNC, and phonics when touching the keypad, the 3684 unit has little to no such warbling and the phonics appear to be gone, or minimized.

It’s not known what Tecsun may have done to address these issues – my review of a previous 3681 firmware unit was published in April, so it’s hard to think that Tecsun made any major physical changes to the PCB/keypad and radio body.  But there does seem to be some improvement.

I had no expectation that a firmware change would result in any improvement in the other major issue common to the 360 series – reduction of sensitivity when the receiver is not being held in the hand.

The 368 still shows a noticeable reduction in signal strength, visible on the display, when left standing on its own versus being fully gripped.  But the problem does not seem to be as serious as it was with the PL-360/365.

And since my first review of the 368, I have done some additional comparisons with older portables which were constructed with more robust cabinets.  Some of those also exhibited reduced sensitivity when not being held.

For the PL-368 with firmware 3684, the headline really has to be the apparent disappearance of the “phonics” when tapping the keypad and cabinet top surface.  This was the elephant in the room on the first very early sample of the PL-368.

While there is still distortion using SYNC mode, this issue seems to have been slightly reduced with the latest firmware.  Without confirmation by Tecsun, there is no way to know what specifically may have been done to impact the SYNC issue in a positive direction.

A major disappointment is confirmation from Anon-Co via Tecsun that the re-calibration function seen in the PL-330, 990x and H-501x is absent from the PL-368.

That leaves a user with only the fine tuning option in SSB.  This is a real puzzler, since surely Tecsun could have enabled re-calibration on the 368 in the same way it did with the other receivers.

SUMMARY

I stated in my first review of the 368 that this receiver would be an automatic must-buy in my book, were it not for the earlier issues of cabinet phonics and signal level reduction when the radio isn’t being fully gripped in hand.

One hopes that the phonics issue has been fully addressed by Tecsun.  It’s possible that my initial early unit of the 368 had some weakness in the PCB for the keypad, and LCD display that has been recognized and corrected.

Without confirmation from Tecsun, it’s also difficult to declare that the 3684 firmware has truly brought about a measurable improvement in SYNC and SSB.  But based on my testing of this particular 3684 firmware unit, the radio is more usable and tolerable in SYNC and SSB.

And of course, addition of the keypad along with multi-bandwidth options moves the 368 firmly into the same zone as Tecsun’s other portables, albeit perhaps more in the “prepper” category.

There are so many offerings now from Tecsun in portables that it’s hard for me to place the PL-368 in the “must-buy” category, especially since the PL-330, 990x and H-501x bring so many superb features to the game.

But the PL-368 has a certain appeal – its walkie-talkie style design makes it an easy quick-grab for trips, similar to the PL-330, though the 368 can not really be safely balanced on a flat surface and is best used with some kind of stand.

In terms of raw performance, one has to observe that the wonderful Belka DX has to be considered as a top choice and major competition when it comes to extreme portability and top performance, especially with the available speaker/battery backs.

And the PL-368 still has major competition from the XHDATA D-808 (now appearing under the RADIWOW SIHUADON label) with excellent AIR band capability and multiple bandwidths, though no synchronous detection.

To “save” the PL-36xx series, Tecsun will have to ensure steady QC (quality control) in manufacturing and when possible, further firmware updates of the 368, as with all Tecsun receivers.


Preliminary List of Hidden Features for PL-368

Source: Anna at Anon-Co

Switch between internal ferrite rod and whip on AM (MW & LW)

1. Select the MW or LW band.
2. Press and hold key ‘3’ for about 2 seconds.

When the display briefly shows “CH-5” this means that the device is set to MW/LW reception using the telescopic antenna. The display shows MW (or LW) and SW on the left side of the screen.

When the display briefly shows “CH-A” this means that the device is set to MW/LW reception using the internal ferrite antenna. The display shows only MW (or LW) on the left side of the screen.

Adjusting the maximum volume level

Select the frequency band, then press and hold key ‘7’ for 2 seconds until a number is displayed. At this moment, rotate the [ TUNING ] knob to adjust and press the key ‘7’ again to save and exit.

Firmware Version

In power-off mode, press and hold [ VF/VM ] for 0.5 seconds until all characters on the display are shown, then wait a few seconds until the firmware version is briefly displayed at upper right of the display.

Extend SW-range for European setting (1621-29999 kHz)

1. In power-off mode, press and hold the [ 3 ] key to set the MW tuning steps to 9kHz.
2. Select the SW band, and then press and hold the [ 5 ] key for 10 seconds to enable/disable the SW frequency extension.

The starting point of the SW frequency range will become 1621 or 1711 kHz.

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