Additional Hidden Feature of Tecsun PL-368

For potential Tecsun PL-368 owners, this is an exciting update! I just received the email below from Anna at ANON-CO:

Hello Robert,

I just wanted to let you know that we are expecting to receive our PL-368 radios around the middle or end of next week. It turns out that these radios will have one (hidden) feature that was not included with the “final” version that you receive in June, and that is a calibration feature for SSB.

If you have any questions please feel free to let me know.

Best regards,
Anna

This is a feature in some of the latest Tecsun models, and seemed odd to not be included in the PL-368, so this is good news indeed!

Cheers, Robert

Robert Gulley, K4PKM (formerly AK3Q), is the author of this post and a regular contributor to the SWLing Post. 

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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: [email protected] 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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FTIOM & UBMP, July 25-31


From the Isle of Music, July 25-31:

This week, our guest is Gastón Joya, whose album with Rolando Luna Fusión de Almas won one of the two Grand Prizes in Cubadisco this year.
The broadcasts take place:
1. For Eastern Europe but audible well beyond the target area in most of the Eastern Hemisphere (including parts of East Asia and Oceania) with 100Kw, Sunday 1500-1600 UTC on SpaceLine, 9400 KHz, from Sofia, Bulgaria (1800-1900 MSK)
2. For the Americas and parts of Europe, Tuesday 0000-0100 UTC on WBCQ, 7490 kHz from Monticello, ME, USA (Monday 8-9PM EDT in the US).
3 & 4. For Europe and sometimes beyond, Tuesday 1900-2000 UTC and Saturday 1200-1300 UTC on Channel 292, 6070 kHz from Rohrbach, Germany.
If you don’t have a shortwave radio or are out of range, you can listen live to uplinks from various websdrs in Europe.
Our Facebook page is https://www.facebook.com/fromtheisleofmusic/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

Uncle Bill’s Melting Pot, July 25-31:
In episode 227, we join the celebrations of Peru’s bicentennial with an hour of Peruvian chicha, timba, afroperuvian music and funk.
The transmissions take place:
1.Sunday 2200-2300 (6:00PM -7:00PM EDT) on WBCQ The Planet 7490 kHz from the US to the Americas and parts of Europe
2. Tuesday 2000-2100 UTC on Channel 292, 6070 kHz from Rohrbach, Germany for Europe.
3. Saturday 0800-0900 UTC on Channel 292, 9670 kHz from Rohrbach, Germany for Europe with a directional booster aimed eastward.
Our Facebook page is https://www.facebook.com/UncleBillsMeltingPot/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

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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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All Tribes Radio: A mission of peace and music via shortwave

Many thanks to SWLing Post contributor, Ken, who shares the following announcement about All Tribes Radio:


ALL TRIBES RADIO

www.alltribesradio.com

ONE PLANET, ONE PEOPLE…. This is ALL TRIBES RADIO and RADIO TODAS LAS TRIBUS, Nosara, Costa Rica

Broadcasting across the globe on shortwave radio, as well as streaming on the internet, All Tribes Radio (ATR) promotes world peace with an eclectic mix of culturally-diverse music, multi-lingual spoken word, and vintage programming from the golden age of radio. We provide a forum for independent artists who have licensed their works through Creative Commons, in addition to providing open-source, public domain, copyleft, and otherwise copyright-free content.

ATR was founded in 2008 by Canadian broadcaster, activist, and musician Ken Dunn (a.k.a. Don Kenet). With studios in Nosara, Costa Rica, Canada, and the U.S., ATR’s signal was transmitted via an internet server in Tampa, Florida. For over two years, the station broadcast an audio stream 24/7 on the internet to an average 6,000 listeners per month in over 120 countries on all continents. Streaming was discontinued in 2011 in favour of podcasting. A total of 68 one-hour podcasts were subsequently produced for iTunes and completed in 2012.

Original All Tribes Radio / Radio Todas Las Tribus Crew, Nosara, Costa Rica
(From Left: Aida Sequeira, Don Kenet, y Chuleta Gabbie)

After a hiatus of eight years, ATR returned to the airwaves in December 2020, this time on Shortwave Radio with a weekly one-hour show broadcast from both WRMI in Okeechobee, Florida and Channel 292 in Rohrbach, Germany.

All Tribes Radio is a non-commercial, non-profit enterprise. However, we are happy to accept donations to offset costs involved in program production and broadcasting. In addition, our membership program provides many benefits to our subscribers.

Peace, health, and happy listening !! Don Kenet, Station Manager, Nosara, Costa Rica.

www.alltribesradio.com

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A simple guide to portable radio power

Over on QRPer.com, I just published a post on portable power that was The Spectrum Monitor magazine’s April 2021 cover article.

This article is essentially an overview of a few different types of rechargeable batteries including pros and cons of each chemistry.

While this article focuses on use in ham radio field applications, it also applies to anyone powering receivers–especially those without an internal power supply–in the field.

Click here to read at QRPer.com.

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REE Noblejas Site Celebrates 50 Years

Many thanks to SWLing Post contributor, Tracy Wood, who shares the following article and translation:

REE Noblejas Site celebrates 50 years.

Radio Exterior de España’s “Amigos de la Onda Corta” latest show marks the history of the 50 years of the Noblejas Broadcast Center.

Program Summary (loose translation)

Noblejas is the voice of Spain in the world, the only shortwave site that Radio Exterior de España currently has to broadcast the country’s events.

The RNE Shortwave Broadcast Center No. 2 was inaugurated on July 21, 1971. It is the largest space in dimensions that the Spanish Radio Television Corporation currently has. For half a century, Noblejas has been the voice of Spain to the world, the only transmission site that Radio Exterior de España currently has after the closure of the centers in Santa Cruz de Tenerife in 1982, Arganda del Rey (Madrid) in 1985 and Cariari de Pococí (Costa Rica) in 2013. It occupies 144 hectares (355 acres) and has a main building with three floors offering 8,000 square meters of useful area, housing four transmitters with which the REE signal is transmitted to all of the Americas, West Africa, the South Atlantic, the Middle East, and the Indian Ocean. The antenna field consists of 27 directional curtain arrays that encompass some three kilometers in length. The Noblejas transmission center has been operating for 50 years. It was only absent for two months (from October to December 2014) when the government wanted to halt REE shortwave broadcasts (ed. – RTVE budget cuts.) Fortunately, the broadcasts returned, and listeners still can enjoy eight hours of daily broadcasting on that band.

(The “Amigos” program notes the station still has available four 100 kilowatt units capable of 6-26 Mhz. REE broadcasts in Spanish, Portuguese, French, Arabic, Russian, English and Sefardí.)

Spanish Audio is here:
https://www.rtve.es/play/audios/amigos-de-la-onda-corta/amigos-onda-corta-50-anos-del-centro-emisor-noblejas-15-07-21/5987840/

Documentary film clip of Francisco Franco at the station’s inauguration is here starting at the 50-second mark:
https://www.rtve.es/filmoteca/no-do/not-1490/1486589/

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