Category Archives: Shortwave Radio

Post-storm power outage leads Emilio to find the RFI-spewing source of his problems

Storm with lighteningMany thanks to SWling Post contributor, Emilio Ruiz, who shares the following guest post:


Apprehending an RFI-generating monster!

At the beginning of the year, I was sad because, at home, an awful RFI noise appeared. The next few months the noise increase until S9!!. Day and night my receivers and my feelings were so dampened with this terrific RFI–only the lower Broadcast Band (900 to 540 Khz) was relatively immune to it.

Yesterday, we had a storm and the mains electricity service went off, so I connect a 12 volt battery to my RT-749b military surplus transceiver and the received signals were very clean like the “good old days”.

(Above: Listen W1AW loong distant from my QTH in Chiapas Mexico).

When the power electricity come back on, so did the RFI too!!

(Above: W1AW gone)

Remembering the recently publish post in SWLing Post about RFI, I did some testing by
cutting the electricity to my home (the main switch) and the RFI was gone!! So I discovered the RFI lives in my house–not in the outside wires!!

I put batteries in my old shortwave portable radio and searched (like Ghostbusters) all outlets contacts, one by one, connect and disconnected each device.

And I found the guilty party!

Exhibit A: The Mitzu laptop power supply

On December 2019, the power supply of my son’s laptop broke, so I bought a cheap substitute.

The RFI produced by this little monster could be heard at a distance of about 200 meters from my QTH!!! (Much like an old transmitter spark gap–!)

Even this cheap power supply apparently featured ferrite toroids on the wire but turns out it is fake!! It was only a plastic ball!

Exhibit B: Fake toroids!

The wires were also not shielded. No doubt one of the worst switched-mode power supplies I could have purchased.

Exhibit C: The Mitzu RFI generator wire without shield, only pair wires!

I found a old Acer power supply with same specs and I replaced out the RFI monster one.

And now? The shortwave bands are clean again.

(Video: Testing my Kenwood R-600 rx with Radio Exterior de España… plugging and unplug the Mitzu monster RFI generator).

So I wanted to share what happened to me, so perhaps it can be useful for other SWLing Post blog friends.

Watch these little switched mode power supplies from all devices in your home. Replace them if you detect RFI levels that harms SWLing. Consider disconnect all devices (vampire consumption–or phantom loads) if not in use; the radio waves and electric bill will be grateful to you!


WOW! What a difference! Emilio, that was great investigative work on your part. It’s as if that switching power supply was specifically designed to create RFI! No shield and fake toroids? That’s just criminal in my world! 

Thank you so much for sharing your story. Hopefully, this might encourage others to investigate and apprehend their own local RFI monsters!

(And by the way, Emilio, I love that RT-749b military transceiver!)

Spread the radio love

New DRM portables announced at IBC 2020

Many thanks to SWLing Post contributor, Ed, who writes:

SWLing Post readers might be interested in reading the Digital Radio Mondiale Newsletter of September 2020, which covers DRM developments announced at IBC 2020.

These include DRM transmitter developments and deployments, and lots of new DRM receivers–such as eight (8) AM/FM/DRM portables, (1) AM/FM/SW/DRM portable, an automotive AM/FM/DRM model, a low-cost automotive AM/FM/SW/DRM model, and an AM/FM/SW/DRM development module with “High quality Tuner Frontend and Audio DAC” from Starwaves in Germany.

URL for newsletter: https://us10.admin.mailchimp.com/campaigns/show?id=5196729

URL for PDF describing new DRM receivers: https://www.drm.org/wp-content/uploads/2020/09/DRM-Receivers-@-Virtual-IBC-9-Sept-2020.pdf

Thank you for the tip, Ed!

Spread the radio love

Radio Waves: Digital Broadcasts in South Africa, Cold War Broadcasting in Late Soviet Era, Possible Ban on RFI Producers in Sweden, and Ham Radio on the ISS

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, Michael Bird,  William Lee, Rob PE9PE, and the Southgate ARC for the following tips:


SABA partners with T&A and Sentech to deliver digital radio in SADC (Advanced Television)

The Southern African community will soon enjoy digital audio broadcasts, thanks to an initiative lead by a South African based entity, Thembeka & Associates that has taken the lead in implementing the much anticipated interactive radio solution.

This was announced by the Secretary-General of the Southern African Broadcasting Association, SABA, Mr Cecil Jarurakouje Nguvauva, following the conclusion of initial agreements between the participating entities. Welcoming the digital radio solution to the SADC region, Nguvauva emphasised the need for rural communities to be engaged fully in the developmental agenda of the respective African governments if the planned development is to add value to the lives of the most disadvantaged members of our society.

Chief Executive Officer of Thembeka & Associates, Madam Thembeka Kaka has hailed this initiative a huge success for the continent and a dream come true for her institution. Madam Kaka added that as a member of the National Committee on ICT Chamber Accessible Broadcasting for People Living with Disabilities, she has passionately driven this project for a long while. Madam Kaka added that “Following the announcement of the Policy Directive that has introduced Digital Sound Broadcasting by the South African Minister of Communications & Digital Technologies, Stella Ndabeni-Abrahams in July this year. I have since realised that greater opportunities have emerged for the broadcast industry as a whole. And this initialises an evolution of radio broadcasts going forward,” she stated.

Sentech’s Meyerton Radio Shortwave site in South Africa will carry the Digital Sound Broadcasting Shortwave Transmission from the broadcast centre in Southern Africa to the rest of SADC countries.

For the initial stage, only six countries are earmarked for the coverage, before it is rolled out to the rest of the SADC Region. The targeted countries are Namibia, Botswana, Lesotho, Eswatini, Zambia and South Africa. The rapid deployment is planned to work alongside the existing analogue radio service, which will seamlessly transition to a fully-fledged Digital Radio transmission in SADC. The receivers to be deployed will have the capabilities to receive and transmit both Analogue and Digital radio signal on FM and AM.

The primary purpose of the initiative is for governments and various newsmakers to urgently provide vital information to all citizens, especially the rural, remote and marginalised vulnerable communities. The outbreak of COVID-19 has amplified the need for this undertaking, that has highlighted risk areas in our various communities. Particular emphasis will be given to the following sectors in the respective communities: Education Sector; Health Sector; Socio-Economic factors; Gender issues; Youth & Disability.[]

Listening Out, Listening For, Listening In: Cold War Radio Broadcasting and the Late Soviet Audience (Wiley Online Library)

Abstract

This article interrogates the well?known phenomenon of western broadcasting to the Soviet Union from the little?known vantage point of the audience’s sonic experience and expression. I use the example of the BBC’s main popular music program in the late USSR, Rok posevy, with its remarkable presenter, Seva Novgorodsev, to explore fundamental questions about the who, how, and why of listening to the so?called “enemy voices.” The popularity of Novgorodsev’s show, I argue, is best understood in the context of the Soviet soundscape and, in particular, of longstanding Soviet media practices, including radio jamming and Soviet ideologies of the voice. Novgorodsev’s Rok posevy presented listeners with a powerful alternative sociocultural space, one that promoted models of authority and community very different from Soviet norms and, indeed, antithetical to Soviet norms.[]

Swedish Electrical Safety Agency threatens ban on sale of optimizers (Southgate ARC)

In Sweden the Swedish Electrical Safety Agency may ban the sale of optimizers used in Solar Panel installations due to the high level of RF Pollution they produce

A translation of an SSA post reads:

The Swedish Electrical Safety Agency wants to remove optimizers that spread interference. “It should be easy for the electrician to do the right thing.”

– We want to remove all solar cell products that spread disruption from the market. It should be easy for the electrician to do the right thing, and if you choose CE-marked gadgets and follow the manufacturer’s instructions, the system should be nice, says Martin Gustafsson, who is an inspector in market control at the Swedish Electrical Safety Agency. reports of disturbing solar cells. In addition to radio amateurs such as Anders Ljunggren, the  mobile operator Telia is among those affected . The Swedish Electrical Safety Board has made inspection visits to disturbing facilities, and carried out a market review of optimizers and inverters from eleven different manufacturers.

“They take advantage of a gap in the standard and instead hide behind a general EMC standard.”

The report is not complete yet. However, one of the conclusions is that a number of manufacturers of interfering products have chosen not to use the standard developed for photovoltaic products, but which has not yet been harmonized by the European Commission.

– They use a gap in the standard and instead hide behind a general EMC standard, which does not make any demands on the dc side. This makes our evidentiary situation difficult. But if the disruption problems are not solved, the products can be banned from sale, says Martin Gustafsson.

Text:  Charlotta von Schultz – www.elinstallatoren.se

Thank you SM5TJH / Janne for the information
Source SSA https://tinyurl.com/SwedenSSA

New Ham Radio Onboard The ISS Is On The Air (K0LWC Blog)

Ham Radio operators have enjoyed making contact with the ISS for many years. The holy grail has always been talking to ISS astronauts on FM simplex (145.800) — but those can be rare chance encounters. Ham radio operators have also enjoyed slow-scan television (SSTV) broadcasts and APRS packet radio via the ISS digipeater. Now we get to work the world’s most expensive FM repeater thanks to the new InterOperable Radio System (IORS) installed on the ISS.

The InterOperable Radio System (IORS) replaces an ancient Ericsson radio system and packet module that were certified for spaceflight over two decades ago. The 5 watt HT that was aboard the ISS was getting worn out after many years of use. The Ericsson radio looks like something from a 1990s episode of Cops.

The new IORS was launched from Kennedy Space Center on March 6, 2020 onboard the SpaceX CRS-20 resupply mission. It consists of a custom space-modified Kenwood D710GA transceiver and an ARISS-developed multi-voltage power supply. The equipment was installed by NASA astronaut Chris Cassidy (KF5KDR).

New Kenwood D710G ‘Space Flight Edition’

The radio now being used is a Kenwood D710G and was engineered specifically for space flight. JVCKENWOOD USA and the ARISS worked closely to modify the D710G. The upgrades were performed by JVCKENWOOD and include:

  • Output power is hardware limited to 25 watts for the safety of the International Space Station
  • Custom firmware and menus tailored for operation onboard the ISS.
  • Higher output/high-reliability fan to allow continuous repeater operation.

Continuous fan operation is an important feature in space for the reliability of the radio. There is no convection in microgravity, so all heat-generating components need to be cooled by moving air or conduction. If the radio burns up, there isn’t a Ham Radio Outlet down the street to grab parts.[Continue reading the the full article at K0LWC’s blog…]


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love

NASA Science Live presents “Our Next Solar Cycle”

Many thanks to SWLing Post contributor, Paul Evans, who writes:

On Tuesday, September 15, 2020 Science at NASA had a presentation on the next solar cycle predictions.

It’s available on YouTube and other outlets without needing a login or Zoom serial number:

Fascinating! Thanks for the tip, Paul!

Spread the radio love

Tecsun PL-990x vs. PL-880: Comparing SSB audio characteristics and pre-production/production PL-990 models

A number of SWLing Post readers have been asking about SSB audio characteristics on the new Tecsun PL-990.

Earlier this week, I took a moment while visiting family to make a few quick comparison videos with the PL-880 outdoors and away from RFI.

As I mention in the videos, there are a lot of cicadas singing in the background and you can also hear a bit of road noise–not ideal for audio, but I had to take advantage of a break in the weather!

You should also note that this isn’t a sensitivity comparison. The radios were pretty close together–if measuring sensitivity, I would have spaced them much further apart. Rather, I hope these videos give you an idea of the audio characteristics in SSB (both CW narrow and voice) and one comparison in AM. If you’re curious about sensitivity and how the PL-990x compares, check out Dan Robinsons initial evaluation.

CW Audio: .5 kHz filter on the 80 meter band

CW Audio: .5 kHz filter on the 30 meter band

SSB audio: 75 meter band

AM Audio: 5 kHz filter WWV 10 MHz

My thoughts

While these videos are far from ideal, they should give you a real-word impression of audio characteristics.

Personally, I think the PL-990x is a much better performer in single sideband. The noise floor is lower, but I think that may have more to do with better filter implementation. I’ve always felt that the PL-880 audio sounds “wider” than the selected filter in the more narrow SSB selections.

In addition, the PL-990x exhibits better SSB stability that’s especially noticeable in CW. The PL-880, at times, almost sounds garbled in comparison.

I also mentioned in the last video that the audio sounds better on the PL-880. I should have qualified that statement a bit better.

In general, yes, the PL-880 audio sounds better because its built-in speaker has slightly better audio fidelity that’s most noticeable when listening to music on the FM band, or a strong local AM station. On shortwave, I feel like I actually prefer the PL-990 audio for all but the strongest stations although I do wish the PL-990 filter could be widened to 9 kHz like the PL-880.

PL-990x (pre-production) vs. PL-990 (production model)

Tecsun Radios Australia reached out and kindly sent me one of their PL-990 production model radios to compare with the PL-990x pre-production model from Anon-Co we’ve been testing up to this point. This has been incredibly helpful as I put together my PL-990 review for the 2021 World Radio TV Handbook.

As I’ve mentioned in previous posts, I feel it can be problematic using a pre-production model radio for review only because there can be differences in quality control when a small number of pre-production units are manufactured compared with a proper first production run (remember this case?).

I’ve only had the production model PL-990 for a few days and most of that time we’ve been dealing with the remnants of hurricane Sally moving through our area dumping torrential rains.

Last night, however, a massive tree fell across our road knocking out power for the better part of 5 hours. This gave me a perfect excuse to start my comparison indoors while rain continued outside.

Based on my comparisons last night, it appears performance is nearly identical between the production and pre-production models. I’ve still more testing to do, but my initial impressions are most positive. Very happy quality appears to be consistent.

Many thanks again to Tecsun Radios Australia for making this comparison possible.

Spread the radio love

Can you help Bruce identify this shortwave noise?

Many thanks to SWLing Post contributor, Bruce (VE6XTC), who is trying to identify noises he’s hearing on the HF bands. Perhaps readers can help.

By request, Bruce has provided me with two recordings via his Kenwood TS-440S:

Recording 1: 7,335 kHz at 0500 UTC on September 13, 2020

Recording 2: 7,405 at 0500 UT on September 13, 2020

Post readers: If you can help Bruce by identifying these HF noises, please comment!

Spread the radio love

ZOE: More Tristan Da Cuhna QSL cards in the wild–?

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


SWLing Post readers may recall the story we published last year about the appearance of a rare QSL card from Tristan da Cunha. ZOE Tristan was for decades one of the most sought after stations — it used 3,290 kHz and had a power of 40 watts.

Recently, I received correspondence from a former editor of the old SPEEDX club bulletin who provided copies of two pages from the bulletin from decades ago. These pages make clear that the QSL I obtained in an Ebay auction was not the card that Dave Sharp received:

Dave was, at one point, editor of the DX Montage section of SPEEDX. As can be seen, the ZOE card that he received was signed by a A.L. Patterson while the one I obtained through auction contained a different signer consistent with a QSL received by South African DX’er Eddie de Lange in 1973. However, the card I received was NOT the one pictured in a story about Tristan published in 2010 — the postmark date is different.

That story noted that three DX’ers from South Africa “did manage to receive and QSL ZOE Radio Tristan – Ray Cader, Gerry Wood and Eddie de Lange were among a handful of fortunate Radio Tristan QSL recipients. I am aware of only two other verifications – UK DX’er Anthony Pearce received a QSL in 1973 and Florida DX’er David Sharp received a verification in 1983.”

Since Dave Sharp noted that his QSL collection was unfortunately lost, the ZOE card I obtained through the eBay auction in 2019 was most likely one received by others in the South African group or possibly by the UK DX’er noted in the 2010 story about Tristan.

The headline out of all of this is that it’s quite possible that other Tristan QSLs are floating around out there.

– Dan Robinson


Wow! Thank you for sharing this follow-up story, Dan!

Readers: Please comment if you have a Tristan Da Cuhna QSL card in your collection! These are rare indeed!

Spread the radio love