International Radio Report reviews the Tecsun H-501x

Many thanks to SWLing Post contributor, Sheldon Harvey, who writes:

Hi, Thomas

Gilles and I have a special edition of the International Radio Report in which we discuss the new Tecsun H-501X portable shortwave receiver.

The special edition is available exclusively on our show’s YouTube channel.

Here is the link to the video:

Thank you for sharing this, Sheldon!

Spread the radio love

Four frequencies will be used for the 2021 BBC Midwinter Broadcast

Many thanks to Richard Hollingham with Boffin Media, who writes:

Hi – I’m (proudly) the Executive Producer of the Antarctic Midwinter Broadcast. It’s made by Boffin Media for the BBC….I’m about to deliver this year’s edition.

In terms of the broadcast itself, following the test on Monday, the BBC’s decided to transmit on all four of the frequencies [noted here] this year.

Because it’s a unique broadcast, the SW version is 30 minutes long whereas the global version is 26′ 29″ (to fit the standard World Service half hour, following the news bulletin). The SW version also has a different introduction as it’s aimed just at our audience of 35 in Antarctica.

Fascinating! Thank you for sharing this, Richard. We’ll be listening!

As a reminder, here are the frequencies courtesy of Richard Langley:

  • 6035 kHz from Dhabbaya
  • 6170 kHz from Ascension
  • 7305 kHz from Woofferton
  • 9505 kHz from Woofferton
Spread the radio love

Reminder: Comb Stereo Broadcast via Radio Gum Tree–June 18, 2021

A quick reminder that the rebroadcast of Radio Gum Tree Episode 2 will take place tomorrow: June 18, 2021 at 9:45 EDT (or June 19, 2021 at 01:45 UTC) on on 5850 kHz. You can find the program notes for these Test broadcasts at this web site address: www.radiogumtree.com/?p=54

Many thanks for putting together this Comb Stereo series, TomL!

For more information, check out TomL’s initial announcement.

Spread the radio love

Jock designs a Horizontal Room Loop to cope with reception issues

Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:


There’s a 50-foot antenna in this room. Can you spot it?

Got reception issues? An idea worth considering: the “Horizontal Room Loop.”

by Jock Elliott (KB2GOM)

When my radio room was in the front of the house (on the east side), it was easy to run a feedline to a large RF-hungry SWL dipole with various stubs and feeders.

Now, however, with my “shack” moved to the SW corner of the house, any attempt to mount an outdoor antenna of any significant length raised potential safety issues because of nearby electrical lines.

Monitoring VHF/UHF is no big deal because of high-performance scanner antennas. HF, however, presents challenges.

My main SWL receiver is a Satellit 800, which has the guts of a Drake R8 and also has a large telescoping vertical antenna. It works okay, but I wanted more signal. I had been looking at small loops and got some great recommendations on Radio Reference, but then I had a thought: what if I turned the 8′ x 12′ room into a giant horizontal passive loop?

Here’s a hint.

So I called a ham friend and ran the idea by him. “Sure,” he said, “give it a try.” He gave me 25 feet of 4-conductor phone wire. Before I could use it, I had to strip off the outer insulation so I could get at the four separate insulated wires inside. The better half helped. Once I had the four wires, I connected two of them together and ran the resultant 50-foot strand around the perimeter of the room by taping the wire to the top of window frames and hiding the wire on the top shelves of book cases. As a result, the horizontal room loop is near the ceiling, about 7 feet in the air, and the room itself is on the first floor.

With the loop in place, I hooked the ends to the clip-in terminals on the back of the Satellit 800.

There’s a switch on the back of the 800 that allows me to quickly compare the loop with the radio’s built-in vertical antenna. And . . . it works! It pulls in more signal than the vertical (as measured on the signal strength meter), but I have not noticed a dramatic reduction in noise. On some stations, the horizontal room loop brings the signal up to full scale, and then the sound is very agreeable indeed.

In all, I am pleased with the results.

For anyone who wants squeeze more performance out of their shortwave receiver, I can recommend giving the horizontal room loop a try. It’s not expensive; it’s relatively easy to do (and undo if you don’t like the results), and just might improve your shortwave reception.

If you are not blessed with a bunch of window frames on which you could tape the wire for your room loop, you’ll have to get creative, but with lightweight wire, you don’t need a massive support structure. Tape, map tacks, or even self-adhesive Velcro segments might work for putting your room loop in place.

I don’t claim that this is the “ultimate” SWL DX antenna, but it certainly improved my situation. Perhaps others have suggestions for improving it.

— Jock Elliott, KB2GOM

Spread the radio love

Analog Devices MxFE RF Data Converter Transceivers could be an SDR game changer

Many thanks to SWLing Post contributor, Paul Evans, who shares info about the new Analog Devices MxFE and notes that it could be a game changer in the world of software defined radio:

This does sound like a very robust and powerful platform although I’m not an engineer so can’t speak to how it might be integrated in affordable SDR receivers and transceivers..

Here’s another information page with specifications about the platform.

Please comment if you’re familiar with this platform!

Spread the radio love

Possible frequencies for the 2021 BBC Midwinter Broadcast

Halley VI: The British Antarctic Survey’s new base (Source: British Antarctic Survey)

Click here to read an update to this post (17 June 2021).

Many thanks to SWLing Post contributor, Richard Langley, who follows up with the following information about the 2021 Midwinter Broadcast to Antarctica:

As usual, there was a test of this year’s possible frequencies yesterday (14 June) from 21:30 to 21:45 UTC.

They were:

    • 6035 kHz from Dhabbaya
    • 6170 kHz from Ascension
    • 7305 kHz from Woofferton
    • 9505 kHz from Woofferton

As has been the case in past years, three of these frequencies will be chosen for the actual broadcast. Here in NB yesterday, good signals were received on 6170, 7305, and 9505 kHz. 6035 kHz was not heard.

Thank you for sharing this, Richard!

Spread the radio love

Radio Waves: “Tuning In The World”, Subcarrier Signals, SSTV Event from the ISS, the Zeptosecond and Israel Army Radio Shut Down

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 Tracy Wood, Dennis Dura, John Forsyth, and the Southgate ARC for the following tips:


Tuning In The World (Far From Home)

When David Goren was 13 years old, he and his family went to visit their Uncle Lou.

“He was usually just railing about my long hair or criticizing rock and roll,” he recalled. But this time was different. “He gave me an old radio of his that had a shortwave band on it. I really didn’t know what that was. I asked my dad, and he was like, ‘You won’t hear anything on that!’”

David was curious, though, so after he got home, he turned it on, started fidgeting with the dial, and was amazed to discover sounds and music from around the world![…]

Click here to read the full post and click here to subscribe to the Far From Home podcast.

Subcarrier Signals: The Unsung Heroes of the FM Dial (IEEE Spectrum)

How subcarrier radio signals made room for hidden FM stations—and helped ensure that everyone has access to the news

A version of this post originally appeared on Tedium, a twice-weekly newsletter that hunts for the end of the long tail.

In our modern era, we tend to choose devices with as many functions as possible, and we bristle at the thought of an object with a single use—hence why umbrellas can be so frustrating to carry around. But sometimes, a single use case is exactly the right level of functionality. This is something I’ve been thinking about recently after I got my hands on a fairly large radio that has literally one function: You turn it on and a specific station plays, and there’s no surface-level way to do anything else with it.

This is a weird device—but for its niche, this device, called a subcarrier radio, was perfect. And it was one of many niches that subcarrier radios made possible.

What the heck is a subcarrier radio signal?
In 1985, a South Florida Sun-Sentinel article discussed a potentially lucrative offering for the owners of FM radio stations: ways to make extra money from parts of the licensed signal they weren’t already using.

This phenomenon was not unusual at the time; the practice had been around for decades. But what the article highlighted were the numerous ways radio signals were being used that the average listener was likely not even aware of—for background music, for stock reports, even to transmit computerized data.

And while station owners weren’t earning a ton of extra money—a single lease brought in US$1,400 a month (about $3,500 today)—for a struggling station, the additional revenue could mean the difference between being in the red and being in the black.

The thing that allows many radio stations to monetize their signals in this way is, essentially, a technical gap inside the FM broadcast signal. These gaps, or subcarriers, are frequencies that aren’t being used for the primary signal but could find secondary uses in more specialized contexts.[]

Amateur Radio on Shuttle, Mir and ISS (Southgate ARC)

ARISS report there will be an ‘Amateur Radio on Shuttle, Mir and ISS’ Slow Scan TV (SSTV) event from June 21-26. Transmissions from the International Space Station will be on 145.800 MHz FM using PD120

The ARISS team will be transmitting SSTV images continuously from June 21 until June 26. The images will be related to some of the amateur radio activities that have occurred on the Space Shuttle, Mir space station and the International Space Station.

The schedule start and stop times are:

Monday, June 21 – Setup is scheduled to begin at 09:40 UTC (transmissions should start a little later).

Saturday, June 26 – Transmissions are scheduled to end by 18:30 UTC.
Downlink frequency will be 145.800 MHz and the mode should be PD120.

Those that recently missed the opportunity during the limited period of MAI transmissions should have numerous chances over the 6 day period to capture many (if not all 12) of the images.

Check the ARISS SSTV blog for the latest information
http://ariss-sstv.blogspot.com/

The signal should be receivable on a handheld with a 1/4 wave whip. If your rig has selectable FM filters try the wider filter for 25 kHz channel spacing.

You can get predictions for the ISS pass times at
https://www.amsat.org/track/

Useful SSTV info and links
https://amsat-uk.org/beginners/iss-sstv/

Meet the zeptosecond, the shortest unit of time ever measured (Space.com)

Scientists have measured the shortest unit of time ever: the time it takes a light particle to cross a hydrogen molecule.

That time, for the record, is 247 zeptoseconds. A zeptosecond is a trillionth of a billionth of a second, or a decimal point followed by 20 zeroes and a 1. Previously, researchers had dipped into the realm of zeptoseconds; in 2016, researchers reporting in the journal Nature Physics used lasers to measure time in increments down to 850 zeptoseconds. This accuracy is a huge leap from the 1999 Nobel Prize-winning work that first measured time in femtoseconds, which are millionths of a billionths of seconds.

It takes femtoseconds for chemical bonds to break and form, but it takes zeptoseconds for light to travel across a single hydrogen molecule (H2). To measure this very short trip, physicist Reinhard Dörner of Goethe University in Germany and his colleagues shot X-rays from the PETRA III at Deutsches Elektronen-Synchrotron (DESY), a particle accelerator in Hamburg.[]

Defense minister says he is sticking to plan to shut Army Radio (The Times of Israel)

Defense Minister Benny Gantz reiterated on Wednesday his belief that Army Radio should not continue in its current format as part of the Israel Defense Forces.

“I think that IDF soldiers must be kept as far as possible from any political involvement, and the station should be apolitical, and it has long stopped being so,” Gantz said in response to a query from Shas MK Moshe Abutbul on the Knesset floor. “I don’t think there is any way to operate Army Radio in its current form, largely due to the political angle.”[…]


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