Radio Waves: Antenna ID, DRM Receiver Requirements Revisited, BBC Broadcasting Technology, and Digital Sound Broadcasting Framework in Kenya

Radio Waves: Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Identify that antenna by sight (Hackaday)

It’s a skill that radio amateurs pick up over years but which it sometimes comes as a surprise to find that is not shared by everyone, the ability to casually glance at an antenna on a mast or a rooftop and guess what it might be used for. By which of course I mean not some intuitive ability to mentally decode radio signals from thin air, but most of us can look at a given antenna and immediately glean a lot of information about its frequency and performance. Is this privileged knowledge handed down from the Elmers at the secret ceremony of conferring a radio amateur’s licence upon a baby ham? Not at all, in fact stick around, and I’ll share some of the tricks. [Continue reading…]

Minimum Receiver Requirement Document Revisited (DRM Consortium)

The latest version of the document (mrr.drm.org) describes the DRM (Digital Radio Mondiale) receiver characteristics for consumer equipment intended for terrestrial reception operating in the frequency bands below 30 MHz (i.e. DRM robustness modes A to D) and also those for the frequency bands above 30 MHz (i.e. DRM robustness mode E). The goals of the document are to: provide guidelines to receiver manufacturers for minimum receiver performance and technical features, to offer confidence to broadcasters that their DRM transmission can be received by all receivers in the market, to assist broadcasters to plan their network and to give full confidence to consumers that all important DRM features are supported by receivers and all DRM transmissions can be received when they acquire a digital DRM receiver.

Click here to download (PDF).

BBC broadcast tech: then and now (Engineering and Technology)

In its centenary year, we look at the BBC’s pivotal role in making the broadcast and radio technology field what it is today.

Daily London broadcasts by the newly formed British Broadcasting Company began from Marconi House on The Strand, on 14 November 1922, using the call sign 2LO, with transmissions from Birmingham and Manchester starting on the following day.

The first broadcast by the young company, which was heard as grainy, muffled speech, was read by Arthur Burrows, who joined the BBC as director of programmes. Notably, he was one of the first people to move from newspaper to broadcast reporting.

At the end of 1922, Scottish engineer John Reith, who was just 33 years old at the time, was appointed general manager of the BBC, which then had a staff of four. Reith is remembered for establishing the tradition of independent public service broadcasting in the United Kingdom.

Within months, the growing organisation moved into the same building as the Institution of Electrical Engineers at Savoy Hill (now the IET’s Savoy Place event venue), where it continued to expand. This was an obvious home for the young BBC, and for the next nine years this is where early innovations of broadcasting occurred.

The British Broadcasting Corporation, as it is known today, was established in January 1927 as a public corporation, and in 1934 it moved from Savoy Hill to the purpose-built Broadcasting House in Portland Place. [Continue reading…]

CA plans digital radio shift on shortage of frequencies (Business Daily Africa)

Kenyan broadcasters will be allowed to adopt a new digital radio standard, which will enable them to use their current spectrum to transmit their signals through a digital network, as the sector regulator moves to address the shortage of analogue frequencies.

The Communications Authority of Kenya (CA) has called for stakeholder and public views on a draft Digital Sound Broadcasting (DSB) framework it has formulated to ensure the efficient use of the available broadcasting spectrum and encourage investment in the sub-sector.

“The objective of this consultation is to develop a suitable framework for Digital Sound Broadcasting in Kenya to address the challenge of high demand and low availability for analogue FM broadcasting frequencies that is currently being experienced,” said the CA. [Continue reading…]

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Readers and friends have spoken: I’m keeping the Sony ICF-SW100

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Yesterday, I published a post listing several radios for sale. These are all portables I haven’t used in a while–I would like them to be in the hands of someone who could put them on the air. I have so many portables that many get overlooked because I’m just one guy. That, and I’m also using the sales a means to build up my radio funds kitty for some future purchases.

In this first post, I mentioned I might sell my Sony ICF-SW100 and that I was on the fence.

Evidently you all know me better than I know me! I received 7 emails and numerous comments urging me to keep the SW100 noting that I would regret selling it.

I’m taking your advice and, frankly, I think you’re right: I believe I would regret this sale. It’s a unique radio and one I desperately wanted in the 1990s, but simply couldn’t afford. It works perfectly, too, so perhaps it’s a sign that I simply need to put it on the air more often.

Thank you for speaking up. I should note that the offers I received on the SW100 were all accompanied with notes telling me that I probably should keep it, too. That’s saying something!

I will be listing more radios here soon including:

A Uniden Bearcat TruckTracker V Scanner (BCD436HP) with GPS antenna
A Marathon ETFR with custom belt case
And possibly one of my Sony ICF-SW7600GRs as I have a total of three

I’ll have even more than this as I work through some of my extras. Stay tuned and thank you for the support!

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Thinning the herd at SWLing Post HQ

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I’m in the process of re-arranging my small office/radio shack and building a dedicated fold-out workbench for all of my projects that require a bit of solder and tinkering.

I need to downsize some of my radio collection to not only free up space but also re-fund the radio kitty. I literally have dozens and dozens of portables–many duplicates. I also don’t like radios to sit on a shelf–I’d rather them be in someone’s hands and on the air. There are a number of portables I use regularly and that I’m keeping for future performance comparisons.

Note that most of these radios are in a price class that likely makes international shipping a moot point (the shipping might cost as much as the radio). I’ve included shipping in the following prices, but this assumes USPS within the US.

If you’re interested in any of the following, contact me at: [email protected]

Also, please not that it could take time for me to reply to your inquiries due to my activities and travels this week.

Sony ICF-SW11 – Update: SOLD

This ICF-SW11 is in superb shape. Comes with original box and paperwork.
$65 shipped USPS to US.

Tivdio V-117 – Update: SOLD

This is a really simple analog display, DSP radio. Performance is respectable for such a super inexpensive radio. Of course, not a DXing machine or anything. $15 shipped USPS to US.

XHDATA D-808 – Update: SOLD

This is a wonderful DSP radio and I’ve had many a good listening session with this unit. If you’re not familiar with this radio, I highly recommend reading 13dka’s review. $90 shipped USPS to US.

Sony ICF-SW100 – Update: Keeping this one after all

I honestly can’t decide if I want to sell my SW-100. I swore I never would and I might change my mind. This one is not cosmetically perfect (perhaps 7 out of 10?)–I purchased it used from Universal Radio and had Vlado (N3CZ) replace the ribbon cable in this unit and tested it thoroughly in 2015. I have traveled extensively with this little radio since and it has served me well. I haven’t used it in ages, though, because as of late I tend to take my CC Skywave SSB or Belka DX since those would be easier to replace if damaged. This would only include the radio and the attachable cover. It works as it should and the battery cover is completely in tact.

If interested, just send me an offer. Full disclosure: I’m truly on the fence about this one and could change my mind.

More to come…

As I dig into my radio reserves, I may find others that I’ll post for sale.

And in case you’re wondering, I’m not leaving the world of shortwave. Not at all. Even after I sell of some extra units, I’ll still have 24 or more portables here. 🙂

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A review of the Tecsun H-501x portable shortwave radio receiver

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I was recently searching for my review of the Tecsun H-501x on the SWLing Post to send to a reader when I realized I had not yet published it here! Let’s fix that…

The following review of the Tecsun H-501x was originally published in the November 2021 issue of The Spectrum Monitor magazine. Enjoy:

A review of the Tecsun H-501x

by Thomas (K4SWL)

Last year [2020], we were treated to a group of new shortwave portables from Tecsun: the PL-990, PL-330, and the H-501.

Although all of these models garnered attention from shortwave listeners, one model in particular seemed to draw the most interest, the Tecsun H-501.

No doubt, much had to do with the H-501’s size––a large format portable––and especially the twin stereo speakers, that no doubt sparked the interest of those of us who owned (or wished we owned) the venerable Grundig Satellit 500 or 700 with its reputation for robust audio.

Tecsun was also very clear during their product announcement in 2019 that the H-501x is the flagship portable for the Tecsun line.

H-501 versus H-501x

Note that the product being evaluated in this review is the H-501x; the latest “export” version of the H-501.

The differences between these two models is fairly modest. The “x” model gives the user a slightly lower frequency floor in longwave and shortwave, and finer FM tuning (50 kHz as opposed to 100 kHz) when the AM tuning steps are set to 9 kHz as opposed to 10 kHz.

The differences are so modest between the H-501 and H-501x, I wouldn’t be worried if you already have the H-501. I would simply encourage you to only purchase from a reputable Tecsun distributor so you can be confident you’re not receiving one of the very early production runs of the H-501 that was only distributed domestically within China. Some of these early domestic models didn’t have all the refinements of the latest H-501 versions. I would encourage you to only purchase the H-501 or H-501x from a reputable distributors like Anon-Co, Waters and Stanton, Tecsun Radios Australia, and Bonito.

Unique features

Besides the large dual speakers of the H-501x, there are a number of other unique features and design choices that truly set the H-501 series apart from other Tecsun models.

Firstly, the H-501x uses two 18650 Lithium Ion batteries housed in two separate battery compartments. Both batteries can be internally charged, but here’s the interesting part: each battery seems to be somewhat independent of the other. When you engage battery charging, you must select, via a mechanical switch on the back of the radio, “Battery A” or “Battery B.” Only one battery can be charged at a time, and thus only one will power the radio at a time.

More than once, I’ve been listening to the H-501x and the battery indicator started flashing, signifying a low battery. I simply switched the battery switch to Battery B, and, voliá: I have a full battery again! This reminds me of a college friend’s VW Beetle that had a spare fuel tank…with this unique feature, when you were running low on fuel, you’d kick in the spare fuel tank and then make plans to refuel the main tank soon. Of course, with the H-501x, both these “fuel tanks” are also generous ones, in that the batteries last for a good while.

I find that the play time of each battery impressive given the size and audio amplification used in the H-501x. I had worries that the unit’s need for two batteries could suggest a short battery life, but fortunately this hasn’t been the case, no matter what mode I’ve used (FM, AM, shortwave, or Bluetooth).

However I will note here that the supplied switching power supply will inject noise if you try listening to AM or shortwave while charging. This hasn’t affected FM reception, though.

The fold-out metal bail on the H-501x is very large. This shouldn’t have surprised me, but it did. The H-501x is tall and wide, but not very deep––only marginally deeper than, say, the PL-880. The bail needed to be low-profile, but also support this mini “wall” of the radio while in use. The metal wire bail is handy and certainly does the trick, although there’s only one tilt position, and when it’s deployed, the radio effectively has a large footprint. This might limit where you can set it if the surface––say, a bedside table––is small. Not a problem for me, but worth noting. Continue reading →

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Carlos’ Shortwave Art and recording of the Voice of Korea (November 4, 2022)

More Wrenaissance on shortwave

Reception Reports Requested: “One-Off” DRM Broadcast From Woofferton To India Today

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Many thanks to SWLing Post contributor, Mangosman, who shares the following announcement from the DRM Consortium:

Encompass Plans A One-off Broadcast From Uk To India On Nov 4th

Encompass Digital Media will be running a one-off transmission from its site in Woofferton, UK, on Friday 4th of November. This electronic music broadcast will target the whole of India, around 5,000 miles (or about 8,000 kilometres) as the crow flies to the centre of the country. This might be the longest distance Encompass has covered with its DRM transmissions.

Before the actual broadcast, several tests were run using different frequencies, antennas and power combinations. The final test on November 2nd to confirm final set-up was a great success as the audio could be recorded from a KiwiSDR online receiver located in New Delhi. The SNR of 20dB was measured in New Delhi and 23.9dB in Bangalore, which proves the power of shortwave radio and how DRM and its excellent sound, even in shortwave, can travel such long distances. The audio was also decoded in Bangkok, and a listener report came even from Canada!

This experimental broadcast promoting the music of C. M. Obrecht is scheduled for tomorrow [today Nov 4 at time of publishing], 19:00 – 20:00 UTC, on 11710kHz. It will use xHE-AAC codec with DRM Mode B, transmitting at 125kW on a 78* bearing from Woofferton. The audio will be accompanied by ancillary data including a slideshow image of the album cover art.

Although the transmission time will mean it will be quite late in India, Encompass is interested in receiving any reception reports from within the country, particularly from anybody using a car radio. Please send reception reports to Steve Palmer at: [email protected] (This is also the address to use for further information about Encompass’ DRM projects and services).

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