Radio Prague celebrates 85 years on the air

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Many thanks to SWLing Post contributor, Jonathan Marks, who recommends this video tour of the Czech Radio Building from Radio Prague’s Facebook page.

Jonathan notes: “[The video os very] nicely done. It compliments episode 4 of the video I made with Olrich Cip”:

Many thanks for sharing this, Jonathan, and for documenting this important piece of our international broadcasting story.

Post readers: If you’d like more information about the 85th Anniversary of Radio Prague, check out this (and other) stories on the Radio Prague Website:

Radio Prague International celebrates 85 years on the airwaves

Although the origins of foreign language broadcasting on Czech Radio stretch as far back as 1926 – in the form of English and French lectures about Czechoslovakia – the birth of the foreign language service is traditionally dated to August 31, 1936, when the Technical Director of Czechoslovak Radio Eduard Svoboda officially announced the beginning of regular foreign language broadcasting.
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Radio Waves: Old Gen FM Radio, Radio Burst Model Challenged, Iceland WebSDR, and Ida Destroys WZRH/KVDU Tower

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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 Dennis Dura, Troy Riedel, Dan Van Hoy, and the Southgate ARC for the following tips:

FM Radio, the choice of an old generation (Hackaday)

Had the pandemic not upended many of this summer’s fun and games, many of my friends would have made a trip to the MCH hacker camp in the Netherlands earlier this month. I had an idea for a game for the event, a friend and I were going to secrete a set of those low-power FM transmitters as numbers stations around the camp for players to find and solve the numerical puzzles they would transmit. I even bought a few cheap FM transmitter modules from China for evaluation, and had some fun sending a chiptune Rick Astley across a housing estate in Northamptonshire.

To me as someone who grew up with FM radio and whose teen years played out to the sounds of BBC Radio 1 FM it made absolute sense to do a puzzle in this way, but it was my personal reminder of advancing years to find that some of my friends differed on the matter. Sure, they thought it was a great idea, but they gently reminded me that the kids don’t listen to any sort of conventional broadcast radio these days, instead they stream their music, so very few of them would have the means for listening to my numbers stations. Even for me it’s something I only use for BBC Radio 4 in the car, and to traverse the remainder of the FM dial is to hear a selection of easy listening, oldies, and classical music. It’s becoming an older person’s medium, and it’s inevitable that like AM before it, it will eventually wane.

There are two angles to this that might detain the casual hacker; first what it will mean from a broadcasting and radio spectrum perspective, and then how it is already influencing some of our projects. [Continue reading…]

New observations challenge popular radio burst model (Sky and Telescope)

Strange behavior caught by two radio observatories may send theorists back to the drawing board.

Fourteen years ago, the first fast radio burst (FRB) was discovered. By now, many hundreds of these energetic, millisecond-duration bursts from deep space have been detected (most of them by the CHIME radio observatory in British Columbia, Canada), but astronomers still struggle to explain their enigmatic properties. A new publication in this week’s Nature “adds a new piece to the puzzle,” says Victoria Kaspi (McGill University, Canada). “In this field of research, surprising twists are almost as common as new results.”

Most astronomers agree that FRBs are probably explosions on the surfaces of highly magnetized neutron stars (so-called magnetars). But it’s unclear why most FRBs appear to be one-off events, while others flare repeatedly. In some cases, these repeating bursts show signs of periodicity, and scientists had come up with an attractive model to explain this behavior, involving stellar winds in binary systems.

However, new observations by European radio telescopes may rule out this model.

Astronomers knew that FRB 20180916B, located in a galaxy some 475 million light-years away, produces multiple bursts about every 16 days, during a ‘window’ that lasts for a few days. “The idea was that the magnetar is part of a binary system with a 16.29-day period,” says Inés Pastor-Marazuela (University of Amsterdam), the first author of the new paper. If the companion star had a thick stellar wind that absorbs radio waves, the bursts would only be visible when the magnetar was on ‘our’ side of the orbit, she explains. [Continue reading…]

New WebSDR in Iceland (Southgate ARC)

Iceland’s IRA reports on August 24 Karl Georg Karlsson TF3CZ connected a new receiver over the internet covering 24-1800 MHz

A translation of the IRA post reads:

QTH is Perlan in Öskjuhlíð in Reykjavík. These are Airspy R2 SDR receivers for 24-1800 MHz (on VHF and UHF). The antenna is a Diamond D-190.

Karl Georg stated the following on FB:
The extension is not just for 2m, it can only be on one band at a time. So if one user switches, others who are connected also move between bands. (However, you can listen to each frequency within the same band). The receiver automatically tunes to APRS QRG 144.800 MHz, see the APRS website: http://SDR.ekkert.org/map

URL of the receiver
http://perlan.utvarp.com/#freq=24890000,mod=usb,sql=-150

Thanks to Karl Georg for his valuable contribution. This is an important addition for radio amateurs who experiment in these frequency ranges, as well as listeners and anyone interested in the spread of radio waves.

IRA Board

Source Iceland’s national amateur radio society, the IRA
https://tinyurl.com/IcelandIRA

WZRH/KVDU Tower Destroyed By Hurricane Ida (Radio Insight)

The nearly 2000 foot tower utilized by Cumulus Media Alternative “Alt 92.3” WZRH LaPlace and iHeartMedia Variety Hits “104.1 The Spot” KVDU Houma LA was toppled by the winds of Hurricane Ida.

The 1999 foot structure was constructed in 1988 to host both signals. Only the bottom 150 to 200 feet remain standing. Both stations are licensed to operate with 100kW/591m, but have low powered auxiliary sites in downtown New Orleans. WZRH is located on the roof of Place St. Charles with 630w/200m. KVDU is on the Hancock Whitney Center with 1.2kW/220m.

In addition to KVDU, iHeartMedia Gospel 940 WYLD is silent at its cluster. The company reports that the remainder of its signals are now operational after all but 93.3 KQUE and 98.5 WYLD-FM were off the air on Monday.

Cumulus Media states that its entire cluster of WZRH, Adult R&B 102.9 KMEZ Belle Chasse, Country “106.1 Nash-FM” WRKN Picayune MS, and Hot AC “106.7 The Krewe” KKND Port Sulphur LA are off the air. [Continue reading…]

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FTIOM & UBMP, September 5-11

China Radio International’s German language service via shortwave ends today, August 31, 2021

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Many thanks to SWLing Post contributor, Gérard Koopal, who writes:

Dear Thomas,

Just received the following message from CRI’s German language service.

They will stop their German language on shortwave from August 31, 2021.

The only way to listen to their German presence will be via the Internet. Sorry that they made this decision since i listened to them on a regular basis. The internet is no substitute for shortwave!

Original announcement in German:

Liebe Radiofreunde,

auch wenn wir am 31. August unser Kurzwellenprogramm in deutscher Sprache einstellen, sind wir als Radio China International (CRI) auf Deutsch natürlich weiterhin für Sie da.

Wie überall in der Welt stehen auch bei uns im Fokus unserer Abeit nun die Neuen Medien. Und genau dort werden Sie uns auch künftig finden. Unter den folgenden Links bieten wir Ihnen auch weiterhin die aktuellsten Informationen aus und rund um China:

http://german.cri.cn/

Facebook: CRI German

APP: China Info

Deutsche Redaktion von CRI

Thank you for sharing this with us, Gérard.

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Kevin’s ATS-25 video series

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Many thanks to SWLing Post contributor, Robert Richmond, who shares the following series of videos about the new ATS-25 receiver (mentioned in this previous post) from Kevin O’Reilly’s YouTube channel.

The ATS-25 – A First Look:

ATS-25 First Power Up:

ATS-25 Useful Features:

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Rare AEG Telefunken E1800 receiver fetches over $5,000 US

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Many thanks to SWLing Post contributor, Dan Robinson, who writes:

A rare AEG 1800 receiver fetched over $5,000 in an auction on the Japan Buyee site, complete with its original metal cabinet.

As collectors/users of premium receivers know, the 1800 was once described as the best HF radio ever made. And this particular unit contained most of the rare main modules that themselves often sell for high prices in Europe.

There were 54 bids for this AEG 1800, demonstrating that rare premium sets such as this, and especially Japan Radio Company (JRC) receivers, still attract major interest from collectors.

Click here to view the completed listing on Buyee.

Most impressive, Dan. It truly amazes me to see the prices rare commercial-grade receivers fetch these days. I’ll be the first to admit that an AEG E1800 would look great in my shack!

Thank you for sharing, Dan.

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Wire antennas vs. mag loop antennas

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In the past few weeks, I’ve gotten a lot of questions from readers who are trying to decide if they should install a magnetic loop antenna or a simple wire antenna at their home. Obviously, most of the questions come from shortwave radio listeners, but some have come from ham radio operators as well.

I realize that there’s a common theme to my answers and I thought it might be useful to share it here on the SWLing Post for future reference. I started to write a slightly more comprehensive article about this, but I quickly realized I want to keep my advice as short and clear as possible. I’ll be painting in broad brush strokes, but here you go:

If you live in an environment with a lot of radio interference…

Magnetic loop antennas are your friend.

By design, mag loop antennas are some of the best antennas for mitigating the radio frequency interference (RFI) that plagues so many of our homes and neighborhoods. When oriented vertically, mag loop antennas can also be rotated to null out unwanted signals on lower frequencies.

Mag loops come in a wide variety of configurations:

The most popular among SWLs are wideband amplified loop antennas manufactured by companies like Wellbrook, Chameleon Antenna, MFJ, DX Engineering, Cross Country Wireless, Bonito, and a number of manufacturers in China. Unlike passive loop antennas, wideband amplified antennas require no manual tuning. These loops do require a power source, typically fed through a Bias-T or batteries.
Passive loop antennas are popular among ham radio operators because they’re easy to build and, unlike amplified loop antennas, one can transmit into them if designed correctly. They’re less popular among radio listeners only because they typically have a very narrow bandwidth and need to be re-tuned (via a variable capacitor) each time you move frequency even a few kilohertz. The NCPL (Noise-Cancelling Passive Loop) which is also known as the Moebius or YouLoop is a bit of an exception and doesn’t require tuning, but does require a receiver with a very high dynamic range.

Loop antennas can also be very stealthy. In fact, Loop on Ground (LoG) antennas are essentially invisible and could be deployed (under the cover of darkness, of course!) in the most restrictive of neighborhoods. ~~Note that since LoGs are horizontal, they are essentially omni-directional.~~ [13dka corrects this in the comments: “This is somewhat ambiguous and not entirely correct: LoGs are horizontally oriented but (somewhat surprisingly) vertically polarized, and even more surprisingly they have the trademark property of verticals”]

We’ve also featured other stealthy loop designs like this porch loop.

As with any antenna, mag loops prefer to be outdoors but can be effectively used indoors if that’s the only option.

If you live in an environment free of radio interference…

Outdoor wire antennas are very hard to beat.

I am a case in point, in fact: I live in a rural, remote location without any meaningful RFI. All of my external antennas are homebrew wire antennas and they serve me incredibly well.

If you’ve been a reader for long, you may note that I don’t personally review amplified magnetic loop antennas often–these are typically published by some of our amazing contributors. This is because I like to do “apples to apples” comparisons and usually don’t have a second compact magnetic loop antenna for comparison here at SWLing Post HQ.

Almost without exception, my cheap homebrew wire antennas outperform wideband amplified mag loop antennas…sometimes, by orders of magnitude.

Many years ago, I tested a Pixel Loop amplified mag loop antenna (now under a different name and sold by DX Engineering) specifically for use on the mediumwave band to null unwanted stations. It was a very capable amplified mag loop antenna, but other than its MW nulling abilities, all of my homebrew wire antennas outperformed it on the HF bands. Reception was, at times, dramatically better on my wire antennas.

Of course, for a wire antenna to perform properly, it needs to be deployed properly. There are excellent resources out there that describe ideal heights and configurations for any given wire antenna design.

Keep in mind that wire antennas can be incredibly stealthy as well. It’s very difficult to see a wire antenna among or in front of a patch of trees, for example. At a previous home, I deployed a horizontal delta loop antenna on my property that–if you knew where to look–was easy to spot from the road. In all of the years we lived there not one neighbor took note, though, because the antenna wire had sky blue jacketing and I deployed it while no one was looking.

Summary

Experiment!

This isn’t an either/or choice for most of us. There’s no harm in building a simple wire antenna and trying it at home first. If the local noise floor is high, then consider adding a magnetic loop antenna to your arsenal as well.

You might find that the wire antenna has an advantage on frequencies where you have less radio interference, and the mag loop serves you well in those portions of the band with thicker RFI and QRM.

Find the best antenna system that works for you at home, but always remember that hitting the field with your radio has advantages as well!

What did I miss?

I omitted numerous antenna designs that aren’t straight-forward loop or simple wires. Check out some designs by our contributors Grayhat, Giuseppe Morlè (IZ0GZW), TomL, and many others here on the SWLing Post. As always, please feel free to comment!

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