Category Archives: AM

Radio Waves: More Cuts to Radio Canada International, RCI Action Comments, End of Radio Disney, Changes to German Phonetic Alphabet and Is FM More Efficient than DAB?

View of the western cluster of curtain antennas from the roof of RCI Sackville’s former transmissions building. Photo from June, 2012.

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 Kris Partridge, Gareth Buxton, Dave Zantow, and Paul R for the following tips:

Canada’s public broadcaster announces new cuts to Radio Canada International (Radio Canada International)

Officials at CBC/Radio-Canada announced a fresh round of cuts at Radio Canada International (RCI) on Thursday as part of a “major transformation” of the beleaguered international service of Canada’s public broadcaster.

A joint statement released by Radio-Canada executive vice-president Michel Bissonnette and his CBC counterpart, Barbara Williams, said the goal of the transformation was “to ensure that the service remains a strong and relevant voice in the 21st-century media landscape.”

“In its strategic plan Your Stories, Taken to Heart, the public broadcaster committed to ‘taking Canada to the world’ and ‘reflecting contemporary Canada,’” the joint statement said.

“Transforming RCI is a necessary step to allow the service to effectively fulfil the important role it must play in delivering on those commitments.

“To that end, RCI will soon be offering more content in more languages, drawing on the work of CBC/Radio-Canada’s respected news teams to reach new audiences at home and abroad.”

Earlier in the morning Radio-Canada executives held a virtual meeting with RCI employees to inform them of upcoming changes.

In all, the transformation will reduce the number of RCI employees by more than half, from the current 20 to nine, including five journalists assigned to translate and adapt CBC and Radio-Canada articles, three field reporters, and one chief editor.

As part of the announced transformation, the English and French language services of RCI will be eliminated and will be replaced by curated content created by CBC and Radio-Canada respectively.

The remaining Arabic, Chinese and Spanish services will also be reduced in size.

However, two new language services – Punjabi and Tagalog – will be added to the editorial offering presented by RCI, officials said.

RCI content will also get more visibility by being incorporated into CBCNews.ca and Radio-Canada.ca with its own portal page featuring all the languages, the statement said.

RCI apps will be folded into the CBC News and Radio-Canada Info mobile apps, while the service’s five existing apps will be deleted, the statement added.

Under the new plan, RCI’s operations will focus on three main areas: translating and adapting a curated selection of articles from CBCNews.ca and Radio-Canada.ca sites; producing a new weekly podcast in each RCI language; and producing reports from the field in Chinese, Arabic and Punjabi.

“This transformation will help bring RCI’s high-quality, relevant content to more people around the globe and allow them to discover our country’s rich culture and diversity,” the statement said.

The union representing Radio-Canada employees lambasted the move as a “rampage.”

“It feels like Groundhog Day with more cuts to RCI under the guise of transformation,” said Pierre Toussignant, president of Syndicat des communications de Radio-Canada (SCRC).

In 2012, CBC/Radio-Canada slashed RCI’s budget by nearly 80 per cent, forcing it to abandon shortwave radio broadcasting altogether. The cuts also resulted in significant layoffs and the closure of RCI’s Russian, Ukrainian and Portuguese language services.[…]

‘Modernizing’ RCI to death! (RCI Action)

On December 3, 2020, Canada’s national public radio and television broadcaster CBC/Radio-Canada announced “a major transformation” of Radio Canada International (RCI) titled “Modernizing Radio Canada International for the 21st century”. And if you didn’t know anything about the toxic relationship between the two, you would really think this was great news.

After all the budget cuts the national broadcaster has imposed on RCI (for example an 80 % cut in 2012) the news this time is more languages, greater visibility, and an expanded editorial line-up.

Let’s take these “improvements” one at a time.

How has CBC/Radio-Canada decided to give “greater visibility” for RCI’s Internet content? They’re going to bury it in inside the CBC and Radio-Canada websites, and not allow RCI to continue on a site that has existed since 1996.

In this same announcement, CBC/Radio-Canada says it’s adding complete sections in Punjabi and Tagalog to the existing services in English, French, Spanish, Arabic and Chinese. In fact it’s adding one “field” journalist to work in Punjabi, and one in Tagalog – not whole sections.

As far as the Spanish, Arabic and Chinese services which each have three seasoned experienced presenter-producers offering tailored content for their target audiences outside Canada, well, they’re all fired. What will remain is one “journalist” per language, who will be obliged to translate texts given to them in English and French.

And now we come to the sections working in Canada’s official languages of English and French. Again, each of these services has three seasoned experienced presenter-producers offering tailored content for an international audience that needs explanations that the domestic service is not obliged to do. So what will Canada’s Voice to the World be obliged to do in this “major transformation”? Fire all six producers and have an editor at CBC, and one at Radio-Canada, choose some stories, and place it on the “RCI website” which is just a section of the CBC and Radio-Canada websites. Yes, the ones that give RCI “greater visibility”.

The CBC/Radio-Canada announcement speaks glowingly about how RCI has provided a Canadian perspective on world affairs, but then starts skidding into talking about “connecting with newcomers to our country”, “engaging with its target audience, particularly newcomers to Canada”, and making this new content “freely available to interested ethnic community media.” Certainly sounds like CBC/Radio-Canada is intent on servicing ethnic communities in Canada.

But there’s a problem. That’s not RCI’s mandate. And CBC/Radio-Canada has no right to change that mandate. Because Canada’s Broadcasting Act, Article 46 (2), makes it a condition of the national public broadcaster’s licence to provide an international service “in accordance with such directions as the Governor in Council may issue.”

And the latest Governor in Council, Order in Council, PC Number:2012-0775, says Radio Canada International must “produce and distribute programming targeted at international audiences to increase awareness of Canada, its values and its social, economic and cultural activities”.

This latest announcement by the CBC/Radio-Canada is, unfortunately, yet another in a string of actions over the last 30 years to eliminate Canada’s Voice to the World.

After failing to shutdown the service in 1990, 1995 and 1996 when pressure from listeners from around the world, and from Canadian Members of Parliament and Senators stopped the closure, the national broadcaster went about dismantling RCI one section after another, one resource after another in a death by a thousand cuts.

This assault on RCI really started in earnest in 1990 when Canada’s Voice to the World was a widely popular and respected international service of 200 employees, broadcasting in 14 languages heard around the world. The 1990 cut removed half the employees, and half the language sections. Over the years, under the guise of streamlining and improving the service, it’s been one cut after another. With this year’s announcement RCI will have a total of nine employees!

Not satisfied with cutting resources, CBC/Radio-Canada has also continually tried to undermine RCI’s international role.

When in 2003 a Canadian parliamentary committee agreed with the RCI Action Committee, in emphasizing RCI’s important international role and suggested more resources should be given to RCI, CBC/Radio-Canada responded by removing two key corporate policies that specifically outlined the necessity for producing programmes for an international audience, again, despite an obligation under the Broadcasting Act.

The reductions in resources, the limiting or decreasing of RCI’s outreach, culminated in 2012 when CBC/Radio-Canada announced it was taking RCI off of shortwave radio broadcasts which had been the main way of communicating to the world since 1945.

This decision deliberately ignored the 2003 Order in Council that specifically obliged CBC as part of its licence to have RCI broadcast on shortwave. Two months after protests by the RCI Action Committee highlighted the illegality of this move, the Canadian Heritage Minister at the time, changed the Order in Council, eliminating shortwave from RCI’s obligations.

This whole sorry tale underlines a key problem facing Radio Canada International:

A domestic national broadcaster is deciding whether or not Canada should have an international voice to the world, and how well it should be funded.

Clearly however, the decision of whether Canada has a Voice to the World and how well it should be funded, should be a decision made by Parliament.

In the meantime, Canadian Heritage Minister Steven Guilbeault should tell CBC/Radio-Canada that it is not allowed to make this latest policy change. Then he should freeze any changes to the service until there is a serious renewal of the Voice of Canada, one that will give it financial and political protection from a toxic relationship with the national broadcaster.[…]

Radio Disney, Radio Disney Country to End Operations in Early 2021 (Variety)

Radio Disney and Radio Disney Country are shutting down early next year.

Disney Branded Television president Gary Marsh announced the news Thursday, which impacts 36 part-time and full-time employees. The move comes as Marsh’s division looks to emphasize the production of kids and family content for streaming service Disney Plus and the linear Disney Channels.

Radio Disney first debuted in Nov. 1996 as a terrestrial broadcast network, aimed at kids, who would pick music playlist by calling a toll-free phone request line. The station was key to amplifying a bevy of musical artists, including the Jonas Brothers, Miley Cyrus, Selena Gomez, Demi Lovato, Hilary Duff, Aaron Carter and others.

Radio Disney Country launched in 2015 as a digital platform, expanding two years later with two Los Angeles terrestrial stations.[…]

Germany to wipe Nazi traces from phonetic alphabet (BBC News)

Germany is to revamp its phonetic alphabet to remove words added by the Nazis.

Before the Nazi dictatorship some Jewish names were used in the phonetic alphabet – such as “D for David”, “N for Nathan” and “Z for Zacharias”.

But the Nazis replaced these with Dora, North Pole and Zeppelin, and their use has since continued with most Germans unaware of their anti-Semitic origin.

Experts are working on new terms, to be put to the public and adopted in 2022.

The initiative sprang from Michael Blume, in charge of fighting anti-Semitism in the state of Baden-Württemberg, backed by the Central Council of Jews in Germany.

The job of devising new terms for the problematic letters is now in the hands of the German Institute for Standardization (DIN).

The commonly-used equivalent in the UK is the Nato phonetic alphabet, with terms such as “F for Foxtrot, T for Tango”. But many English speakers also use terms like “D for Dennis, S for Sugar” on the phone.[…]

Click here for the Newsroom audio via BBC Sounds.

How much energy is used to deliver and listen to radio? (BBC Research and Development)

Is FM radio more energy-efficient than DAB? Do transmitters or audio devices consume the most electricity? What effect will switching off certain radio platforms have on energy use? As part of our work to improve the environmental impact of BBC services, we now have the answers to these questions and more.

Today, we are publishing our research which explores the energy footprint of BBC radio services, both as it stands now and how it may change in the future. This work is the first of its kind in analysing the novel area of radio energy use and forms an extension to the research we released back in September looking at the environmental impact of BBC television.

In our study, we considered the energy use across all available platforms, namely AM, FM, DAB, digital television (DTV) and via internet streaming services (such as BBC Sounds), revealing which ones have the largest footprints. We also compared energy use at various stages in the radio chain – not just looking at what the BBC is directly responsible for, such as preparation (playout, encoding and multiplexing) and distribution (transmitters and internet networks), but also in the consumption of our content by audiences. This highlighted the key energy hotspots in the BBC radio system and where best to focus our efforts if we want to reduce our energy footprint.[…]

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

How to Build a Simple Linear-Loaded Dipole for Low-Noise Shortwave Radio Listening

14 Replies

Many thanks to SWLing Post contributor and RX antenna guru, Grayhat, for another excellent guest post focusing on compact, low-profile urban antennas:

A linear loaded dipole for the SWL

by Grayhat

What follows is the description of an antenna which may allow to obtain good performances even in limited space, the antenna which I’m about to describe is a “linearl loaded dipole”(LLD) which some call the “cobra” antenna due to the “snaking” of its wires
The arms of the antenna are built using 3-conductors wire (which may be flat or round) and the 3 conductors are connected this way:

That is, connected “in series”, this means that, the electrical length of the antenna will be three times its physical one; this does NOT mean that the antenna will perform like a single wire of the same (total) length, yet it allows to “virtually” make it longer, which in turn gives it good performance even with relatively short sizes. Plus, the distributed inductance/capacitance between the wires not only gives it a number of “sub” resonance points, but also helps keeping the noise down (in my experience below the noise you’d expect from a regular dipole). At the same time it offers better performances than what one may expect from a “coil loaded” dipole. Plus, building it is easy and cheap and the antenna will fit into even (relatively) limited spaces (a balcony, a small yard and so on…).

Interested–? If so, read on and let me start by showing my (short – 9mt total) LLD installed on a balcony:

Here it is in all its “glory”–well, not exactly–I fiddled with it lately since I’m considering some mods so the tape isn’t correctly stuck and it has been raised and lowered quite some times, but in any case that’s it.

Bill of Materials

Here’s what you’ll need to build it (the links are just indicative, you may pick different stuff or buy it locally or elsewhere).

Some length of 3-conductors electrical wire which will fit your available space (pick it a bit longer to stay on the safe side), it may be flat or round, in my case I used the round type since it was easily available and cheap: https://amzn.to/3g2eZX3
A NooElec V2 9:1 BalUn–or, if you prefer you may try winding your own and trying other ratios. I tested some homebuilt 1:1, 1:4 and 1:6 and found that the tiny and cheap NooElec was the best fitting one): https://amzn.to/3fNnvce
A small weatherproof box to host the BalUn: https://amzn.to/33vjZy3
A center support which may be bought or built. In the latter case, a piece of PCV pipe with some holes to hold the wires should suffice. In my case I picked this one (can’t find it on amazon.com outside of Italy): https://www.amazon.it/gp/product/B07NKCYT5Z
A pair of SMA to BNC adapters: https://amzn.to/37krHwj
A run of RG-58 coax with BNC connectors: https://amzn.to/2JckHcR

Plus some additional bits and pieces like some rope to hang the antenna, some nylon cable ties, a bit of insulated wire, duct tape and some tools. Notice that the above list can be shortened if you already have some of the needed stuff and this, in turn will lower (the already low) cost of the antenna.

Putting the pieces together

Ok, let’s move on to the build phase. The first thing to do will be measuring your available space to find out how much wire we’ll be able to put on the air; in doing so, consider that (as in my case), the antenna could be mounted in “inverted Vee” configuration which will allow to fit the antenna even in limited space.

In any case, after measuring the available space, let’s subtract at least 1m (50cm at each end) to avoid placing the antenna ends too near to the supports. Also, if in “inverted Vee” config, we’ll need to subtract another 50cm to keep the feedpoint (center/box) away from the central support.

Once we’ve measured, we may start by cutting two equal lengths of 3-conductor wire. Next, we’ll remove a bit of the external sleeve to expose the three conductors and then we’ll remove the insulator from the ends of the three exposed wire (and repeat this at the other end of the cable and for both arms).

The resulting ends of each arm should look somewhat like in the example image below

Now we’ll need to connect the wires in series. We’ll pick one of the cables which will be the two arms of our antenna and, assuming we have the same colors as in the above image, we’ll connect the green and white together at one end and the black and green together at the other end. Repeat the same operation for the second arm and the cables will be ready.

Now, to have a reference, let’s assume that the ends of each arm with the black “free” (not connected) wire will go to the center of our dipole.

Leave the two arms alone for a moment, and let’s install the balun inside the waterproof box. To do so, we’ll start by cutting a (small) hole through the single rubber cap found at one side of the box, then insert the cap reversed, so that it will protrude to the inside of the box and not to the outside. Slide the balun SMA connector through the hole so that it will protrude outside the box.

Now use a marker to mark the balun position and remove the balun from the box. Pick a piece of wood/plastic or other insulating material, cut it to size (refer to marking and to balun size) and drill four holes matching the one found on the balun board. Slide four screws through the holes and lock them with nuts, the screws should be long enough to extrude for some mm. Now insert the balun in the screws using the holes present on the balun board and lock it with nuts (be gentle to avoid damaging the balun). At this point, add some “superglue” to the bottom of the support we just built, slide the balun SMA connector through the rubber cap hole we already practiced, and glue the support to the bottom of the waterproof box. Wait for the glue to dry.

Just to give you a better idea, see the photo above. That’s a photo of the early assembly of my balun. Later on, I rebuilt it as described above (but took no pics!), the image should help you understanding how it’s seated inside the box–by the way in our case it will be locked by the screws to the plastic support we glued to the box.

While waiting for the glue to dry, we may work on the dipole centerpiece.

If you bought one like I did, connecting the arm “black” (see above) wires should be pretty straightforward. If instead you choose to use a PVC pipe you’ll have to drill some holes to pass and lock the wire so that the strain will be supported by the pipe and not by the wire going to the balun box. In either case, connect a pair of short runs of insulated wire to the end (black) wire coming from each end. Those wires should be long enough to reach the balun wire terminal block inside the box.

Assuming the glue dried, it’s time to complete the feedpoint connection.

Bring the two wires coming from the centerpoint inside the waterproof box. Pick one of the wire terminal blocks which came with the balun (the “L” shaped one should be a good choice) and connect the wires to it. Then, slide the block in place until it locks firmly. After doing so, close the box and screw the SMA-BNC adapter onto the SMA connector coming from the balun. Our centerpiece and arms will now be ready, and will be time to put our antenna up!

I’ll skip the instructions about holding the arm ends and the centerpiece up, since I believe it should be pretty straightforward. Just ensure to put the antenna as high as possible and, if you have room make the arms as long as possible. In my case, due to my (self-imposed) limitations, the antenna was installed on a balcony. The arms have a length of about 3.5m each and the feedpoint (in the image above) sits at about 9m off the ground.

The more acute readers probably noticed those “blobs” on the coax, they are snap-on ferrite chokes I added to the coax (there are more of them at the rx end) to help tame common mode noise. I omitted them from the “BoM” since they may be added later on.

Anyhow, now that you have your LLD up it will be time to give it a test! In my case, I decided to start by running an FT8 session to see what the antenna could pick up during 8 hours, and the result, on the 20 meters band, is shown on the following map (click to enlarge):

Later, that same antenna allowed me to pick up signals from the Neumayer station in Antarctica–not bad, I think!

Some final notes

While running my “balcony experiment”, I built and tested several antennas, including a vanilla “randomwire”, a dipole, and a T2FD.

Compared to those, the LLD offers much less noise and better reception on a wide frequency range. By the way, it won’t perform miracles, but it’s serving me well on the LW band, on most ham bands, and even up to the Aircraft bands–indeed, was able to pick up several conversations between aircraft and ground air traffic control.

All I can suggest is that given a linear-loaded dipole is so simple, quite cheap, and may fit many locations, why don’t you give it a spin–?

Spread the radio love

Radio Waves: Ajit Pai to Resign, Hams Need to Embrace Hacker Community, Coast Guard Might Abandon HF Voice Watchkeeping, and FCC Action Against Unauthorized Transceivers

7 Replies

Radio Waves: Stories Making Waves in the World of Radio

FCC Chairman Ajit Pai to leave agency on Inauguration Day (PBS News Hour)

Federal Communications Commission Chairman Ajit Pai, a Republican, says he is leaving the telecommunications regulator on Inauguration Day.

President-elect Joe Biden will choose a new Democratic head for the agency. A new administration typically picks a new chairman.

Pai has presided over a contentious FCC over the last four years. He undid net neutrality rules that barred internet service providers like Comcast and AT&T from favoring some types of online traffic over others in 2017 and championed other deregulatory efforts. He has also worked to free up spectrum for cellphone companies so they can roll out 5G, the next-generation wireless standard that promises faster speeds, and cracked down on Chinese telecom companies as national security threats.

The incoming FCC is likely to try to reinstate net neutrality rules and focus on closing the “digital divide,” getting internet service to Americans who don’t have it because it’s not available or they can’t afford it.[…]

Ham Radio Needs To Embrace The Hacker Community Now More Than Ever (Hackaday)

As many a radio amateur will tell you, ham radio is a hobby with as many facets as there are radio amateurs. It should be an exciting and dynamic place to be, but as those who venture forth into it sometimes sadly find out, it can be anything but. Tightly-knit communities whose interests lie in using $1,000 stations to chase DX (long-distance contacts), an advancing age profile, and a curious fascination of many amateurs with disaster communications. It’s something [Robert V. Bolton, KJ7NZL] has sounded off about in an open letter to the amateur radio community entitled “Ham Radio Needs To Embrace The Hacker Community Now More Than Ever“.

In it he laments that the influx in particular of those for whom disaster preparedness is the reason for getting a licence is to blame for amateur radio losing its spark, and he proposes that the hobby should respond by broadening its appeal in the direction of the hacker community. The emphasis should move from emergency communications, he says, and instead topics such as software defined radio and digital modes should be brought to the fore. Finally he talks about setting up hacker specific amateur radio discussion channels, to provide a space in which the talk is tailored to our community.[…]

Coast Guard Proposes to Discontinue HF Voice Watchkeeping (ARRL News)

The US Coast Guard has invited comments by January 21, 2021, on a proposal to discontinue HF voice watchkeeping. The proposal [PDF] appeared on November 20 in the Federal Register. The USCG proposes to cease monitoring 4125, 6215, 8291, and 12,290 kHz, in the contiguous US and Hawaii, due to a lack of activity.

“We believe this change would have a low impact on the maritime public, as commercial satellite radios and Digital Selective Calling (DSC) marine-SSB HF radios have become more prevalent onboard vessels,” the Coast Guard said. “However, we would like your comments on how you would be affected if we terminated monitoring HF voice-only distress frequencies within the contiguous US and Hawaii, particularly if you use HF, but do not currently have a commercial satellite radio or an HF DSC-capable radio aboard your vessel.”[…]

FCC takes action against marketing of unauthorized transceivers (Southgate ARC)

On November 24 FCC Enforcement Bureau (EB) issued a citation and order concerning the illegal marketing of unauthorized radio frequency devices

The citation says:

This CITATION AND ORDER (Citation), notifies Rugged Race Products, Inc. d/b/a
Rugged Radios (Rugged Radios or Company) that it unlawfully marketed six models of radio frequency devices that (a) operated outside the scope of their respective equipment authorization, or without any equipment authorization; (b) permitted any operator to program and transmit on new frequencies using the device’s external operation controls; and (c) lacked the appropriate labeling. Specifically, Rugged Radios marketed models RH5R-V2, RM25R, RM25R-WP, RM50R, RM60-V, and RM100 in violation of section 302(b) of the Communications Act, as amended (Act), and sections 2.803(b), 2.925(a)(1), 80.203(a), 90.203(a), 90.203(e), 95.361(a), and 95.391 of the Commission’s rules.

Read the Citation and Order at
https://docs.fcc.gov/public/attachments/DA-20-1395A1.pdf

Source FCC Enforcement Bureau
https://www.fcc.gov/enforcement

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

Matt’s Monster Mediumwave Radio Selectivity Shootout!

9 Replies

Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), for sharing another brilliant audio comparison featuring benchmark portable radios:

Medium wave selectivity shootout

by Matt Blaze

I did another monster medium wave portable receiver comparison, this time with the aim of comparing receivers’ ability to deal with weak signals in the presence of strong adjacent channels.

Once again, I went up to the roof with eight MW portables with built-in antennas and recorded them simultaneously along with my “reference signal”, from an Icom R-9500 with an active loop on the roof. As before, I recorded a narrated stereo mix with the Icom on the left and the rotation of radios for a minute or two each on the right, but have “solo” tracks available for the full time for each radio. The nine receivers in the lineup this time included:

Icom R-9500 (with amplified Wellbrook loop antenna on roof)
Potomac Instruments FIM-41 Field Intensity Meter (my personal favorite)
Panasonic RF-2200
Sony IC-EX5MK2
C.Crane Radio 2E
Sangean PR-D4W
Sangean ATS-909X
Tecsun PL-990X
XHDATA D-808

I recorded two signals, one at night and one during the day.

Nighttime Signals

The first was at night: WWL New Orleans on 870 KHz. This signal is usually weak to medium strength here, but is a challenge for two reasons: first, it shares the frequency with Cuba’s Radio Reloj, and it is squeezed between two much higher strength signals: Toronto’s CJBC on 860, and NYC’s WCBS on 880. So you need a decent receiver and careful antenna orientation to receive it well here. That said, everything did pretty well, though you can see that some radios did better than others.

The mix

Audio Player

00:00

00:00

Use Up/Down Arrow keys to increase or decrease volume.

Daytime Signals

The second signal was during the day and was MUCH more marginal: WRJR Claremont, VA on 670 KHz. This was real challenge for any receiver and antenna. The signal was weak, and overshadowed by WCBM Baltimore on 680, a 50KW daytimer that is very strong here. (I’m not 100% sure that we were actually listening to WRJR – I never got an ID, but the station format and signal bearing was right). We can really hear some differences between the radios here.

The mix

Audio Player

00:00

00:00

Use Up/Down Arrow keys to increase or decrease volume.

Everything (except the Icom) was powered by batteries and used the internal MW wave antenna, oriented for best reception by ear (not just maximizing signal strength, but also nulling any interference). The loop for the Icom was similarly oriented for best intelligibility.

For audio nerds: The recording setup involved a lot of gear, but made it fairly easy to manage capturing so many inputs at once. The portable radios were all connected to a Sound Devices 788T recorder, with levels controlled by a CL-9 linear mixing board control surface. This both recorded the solo tracks for the portables as well as providing a rotating mix signal for each receiver that was sent to the next recorder in the chain, a Sound Devices 833. The 833 received the mix audio from the 788T, which went directly to the right channel. The left channel on the 833 got audio from a Lectrosonics 822 digital wireless receiver, which had the feed from the Icom R-9500 in the shack (via a Lectrosonics DBu transmitter). The center channel on the 833 for narration of the mix, which I did with a Coles 4104B noise-canceling ribbon mic. This let me record fairly clean audio in spite of a fairly noisy environment with some wind.

All the radio tracks were recorded directly off the radios’ audio line outputs, or, if no line out was available, from the speaker/headphone jack through a “direct box” interface. I tried to make the levels as close to equal as I could, but varied band conditions and different receiver AGC characteristics made it difficult to be completely consistent.

Making the recordings was pretty easy once it was set up, but it did involve a turning a lot of knobs and moving faders in real time. I must have looked like some kind of mad scientist DJ to my neighbors, some of whom looked at me oddly from their own roofs.

Happy Thanksgiving weekend!

Thank you, Matt, for another brilliant audio comparison! I appreciate the attention and care you put into setting up and performing these comparisons–not an easy task to say the least. That Potomac Instruments FIM-41 is an impressive machine!

By the way, I consider it a badge of honor when the neighbors look at me as if I’m a mad scientist. I’m willing to bet this wasn’t your first time!

Post readers: If you like this audio comparison, please check out Matt’s previous posts as well:

Spread the radio love

A True Treasure Trove: International Radio Club of America Free Reprints

4 Replies

Many thanks to SWLing Post contributor, Nick Hall-Patch, who writes:

Since 1964, the International Radio Club of America has been documenting medium wave DXing and DXers’ efforts to improve their understanding of radio reception and to develop better listening techniques. During that time, over 900 articles have been written, that have furthered the art of DXing. Many of these continue to be relevant to the more general radio hobbyist, including articles about antennas, radio propagation, receivers and accessories, plus general technical information.

Previously, those articles were available only to club members, but they are now available to all. Go to www.ircaonline.org, and click on the “Free IRCA Reprints” button to download your own copies.

Oh wow! What an amazing and deep treasure trove of articles! Thank you so much for the tip, Nick!

Spread the radio love

Radio Deals: C.Crane CCRadio 2E $20 off today only

Radio Waves: Solar-Powered Broadcast Transmitters, Decommissioning Arecibo, and HWN in the path of an International Broadcaster

6 Replies

Arecibo Observatory’s 305-meter telescope in November of 2020 (Credit: University of Central Florida)

Radio Waves: Stories Making Waves in the World of Radio

Many thanks to SWLing Post contributors Jerome van der Linden, Zack Schindler, and Wilbur Forcier and for the following tips:

Powering communication networks using solar power (BAI Communications)

BAI Communications (BAI) is committed to reducing emissions and contributing to a more sustainable future.

Over the past four years, BAI has invested in a number of initiatives that reduce power consumption as well as the carbon released into the atmosphere.

This year, four solar-powered sites were introduced in BAI’s broadcast transmission network; Yatpool, Victoria; Mawson, Western Australia; Minding, Western Australia; and Brandon, Queensland.

The annual reduction in CO2 emissions from our recent solar investment is 698 tonnes, equivalent to reducing:

Greenhouse gas emissions from 2.7km driven by an average passenger vehicle

CO2 emissions from charging 89 million smartphones

Greenhouse emissions from 237 tonnes of waste sent to landfill

Find out how BAI implemented this solar power initiative as part of our commitment to managing our energy use and reducing consumption.

Click here to download case study (PDF).

The complexity of sending sounds to (and from) space (Mashable)

Communication with astronauts in space is vital, whether it’s during travel, when they’re doing experiments on the International Space Station, or just want to chat. It’s also pretty tricky.

That’s the topic of the latest episode of Twenty Thousand Hertz, where host Dallas Taylor speaks with International Space Station commander Peggy Whitson, NASA audio engineer Alexandria Perryman, and astrophysicist Paul Sutter to get an idea of how communication between astronauts and Earth works across the vacuum of space.[…]

NSF to decommission Arecibo radio telescope (Space News)

WASHINGTON — The National Science Foundation announced Nov. 19 it will perform a “controlled decommissioning” of the giant radio telescope at the Arecibo Observatory in Puerto Rico, citing recent damage that made it unsafe to operate or even repair.

In a call with reporters, NSF officials said two broken cables used to support a 900-ton platform suspended over the telescope’s 305-meter main dish put the entire structure at risk of collapse. One cable slipped out of its socket in August, falling to the dish below and damaging it, while the second broke Nov. 6

Both cables are attached to the same tower, one of three surrounding the main dish. “The engineers have advised us that the break of one more cable will result in an uncontrolled collapse of the structure,” said Ralph Gaume, director of the NSF’s Division of Astronomical Sciences, referring to cables attached to that same tower. That would result in the platform crashing down to the main dish and potentially toppling one or more of the towers.

Engineers advising the NSF and the University of Central Florida (UCF), which operates Arecibo for the NSF, concluded that it was not possible to safely repair the structure because of the collapse risk. “After the recent failure, WSP does not recommend allowing personnel on the platform or the towers, or anywhere in their immediate physical vicinity in case of potential sudden structural failure,” stated WSP, one engineering firm involved in that analysis, in a Nov. 11 letter to UCF.

“NSF has concluded that this recent damage to the 305-meter telescope cannot be addressed without risking the lives and safety of work crews and staff, and NSF has decided to begin the process of planning for a controlled decommissioning of the 305-meter telescope,” said Sean Jones, assistant director of the NSF’s Mathematical and Physical Sciences Directorate.

Engineers are working on a plan to carry out that controlled decommissioning, which will take several weeks to complete.[…]

International Broadcast Station Interference Overwhelms Hurricane Watch Net (ARRL News)

As Category 4 Hurricane Iota neared landfall in Central America on November 16, the Hurricane Watch Net (HWN) was forced to suspend operations at 0300 UTC because of what HWN Manager Bobby Graves, KB5HAV, described as “deafening interference from a foreign AM broadcast station that came out of nowhere at 0200 UTC.” At the time, the net had shifted to its 40-meter frequency of 7.268 kHz, collecting real-time weather and damage reports via amateur radio.

“This was heartbreaking for our team, as the eyewall of Iota was just barely offshore,” Graves said. “The storm had weakened slightly to a Category 4 hurricane with sustained winds of 155 MPH.” After activating at 1300 UTC, the net was able to collect and forward reports from various parts of Nicaragua and Honduras via WX4NHC throughout the day for relay to forecasters at the National Hurricane Center in Miami. Iota was the most powerful storm on record to make landfall this late in the hurricane season.

Graves said the very strong AM signal was on 7.265 MHz. “From my location, it was S-9,” he told ARRL. “You could not hear anything but the BC station.” The source of the signal was not clear, but as he noted, other foreign broadcast stations are to be heard from 7.265 to 7.300 MHz and splattering close by.

Stations handling emergency traffic during the response to Category 5 Hurricane Iota had requested clear frequencies on November 16 to avoid interfering with the HWN and with WX4NHC, as well as with a Honduran emergency net operation on 7.180 MHz and a Nicaraguan emergency net operating on 7.098 MHz. It’s not known if those nets were also affected by interference from the numerous broadcasters on 40 meters. “Thank you to all who allowed us a clear frequency,” Graves said on behalf of the HWN.[…]

[Personal note: I understand that this is very late in the season for the Hurricane Watch Net to activate. Normally, they operate on 20 meters, but moved to 40 meters for the evening. I don’t believe net control was aware that this portion of the 40 meter band is shared with international broadcasters. I don’t believe the international broadcaster could be called “interference”–they operate on a publicly available schedule–ham radio nets are actually the ones who are frequency agile. This seems to have just caught them off guard. I believe the HWN will be using frequencies below 7.2 MHz moving forward.]

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