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!
The unlikely story of an American ham radio amateur and her conversations with cosmonauts in space (PRI’s The World)
In the 1980s, Margaret Iaquinto was an amateur ham radio operator who communicated with Russian cosmonauts in space. She talked to them for over a year. Iaquinto died in 2014. But her son Ben Iaquinto remembers the friendships she developed with the cosmonauts. Marco Werman speaks to Ben Iaquinto about his mom’s hobby and the conversations she had with these Russian cosmonauts.
Radio Stations Shut Or Power Down At Night, Because Of The Laws Of Physics (IFL Science)
If you’re a radio fan, or have merely been stuck in a car as day transitions into night, you may have noticed that you don’t get quite as clear signal in the hours of darkness.
Before you assume that it’s a plot by reverse vampires (possibly in conjunction with the saucer people) in order to make radio listeners go to bed, you should know that it’s actually the result of a requirement by the Federal Communications Commission (FCC) to power down or turn off at night, and the FCC in turn are required to do this by the laws of physics.
It all has to do with wavelengths and the ionosphere. During the daytime, AM signals primarily propagate close to the ground (known as ground wave propagation) and follow the curves of the Earth. In the daylight hours, AM signals sent by radio stations can cover around 162 kilometers (100 miles) before you will struggle to hear the signal.
As good as this is, at night the ability of long waves to propagate large distances becomes a problem, thanks to the ionosphere. Between 80 and 600 kilometers (50-373 miles) above the Earth, particles in the Earth’s atmosphere are bombarded with Extreme Ultraviolet (EUV) and x-ray solar radiation, ionizing them as they do so. The ionosphere grows and shrinks (on your side of the planet) depending on the time of day.
At night, the layer reflects AM radio signals (known as “skywave” propagation) to a much greater degree than during the day, allowing the signal to be carried for hundreds of miles further than during the day. While this may sound like good news, it is what’s known as a “pain in the butt” for any communication regulators out there, or people who want to listen to anything other than an indiscernible mess of static.
“Because of this change in signal propagation from daytime to nighttime, if every AM station kept its daytime operating power at night, massive interference would result,” the FCC explains on their website. [Continue reading…]
Islanders’ interest in amateur radio surges because of COVID-19 and Fiona (CBC)
‘The sky’s the limit. There’s just so many different things that you can learn’
The amateur radio community on P.E.I. is growing, thanks in part to the COVID-19 pandemic and post-tropical storm Fiona.
Stratford resident Brent Taylor has been a ham radio operator for 38 years, in New Brunswick and P.E.I. He goes by the call sign VY2HF.
“It’s been absolutely fantastic. We have been so thrilled with the number of people that have come forward, and now that we’re getting them on the air,” Taylor said.
“Probably because of COVID, and maybe because of Fiona, there’s been a more of an interest, I think, in people wanting to be able to maintain their connections with each other, even from their own homes.”
Taylor said a dozen people started the 12-week training program in the fall, and eight passed their exams and are now licensed operators.
“The most diverse I’ve ever seen. And I’ve been teaching off and on this course for 35-plus years. To see the number of women in the course, for one thing, is just tremendous,” Taylor said.
“Also, cultural diversity and a wide range of ages from as young as 12 years old.” [Continue reading…]
No more airplane mode? EU to allow calls on flights (BBC)
Airline passengers in the European Union (EU) will soon be able to use their phones to full effect in the sky.
The European Commission ruled airlines can provide 5G technology on board planes, alongside slower mobile data.
This could mean flyers will no longer be required to put their phone on airplane mode – though the specifics of how it will be implemented are unclear.
The deadline for member states to make the 5G frequency bands available for planes is 30 June 2023.
This will mean people can use all their phone’s features mid-flight – enabling calls as well as data-heavy apps that stream music and video.
Thierry Breton, EU Commissioner for the Internal Market, said the plan would “enable innovative services for people” and help European companies grow.
“The sky is no longer a limit when it comes to possibilities offered by super-fast, high-capacity connectivity,” he said. [Continue reading…]
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Bob,
Many new vehicles have HD radio built in, but you may have to search for it on the infotainment system.
https://www.walmart.com/c/kp/hd-radio You must see if they actually have stock of that model as they are not big sellers. Also the programming is in stereo, but nearly all of those shown only have one speaker. So for good sound you will need to use headphones either Bluetooth if the receiver has that facility or via a cable.
The channelling problems in the AM band are not a problem in the FM band for analog radio because the channels are 200 kHz wide and this is the width of the signal. However HDRadio in that band also uses adjacent channels to carry the digital signal.
In both AM and FM the power of the digital signal is much weaker than the analog signal meaning that the coverage area is much reduced. This is to reduce interference! Receivers automatically go to analog if the digital reception is full of errors. If you are listening to HD2 – HD4 the receiver will just mute if the errors are too great.
The point of my previous posting was that medium-wave AM broadcasting is not what one would describe as a growth industry; and it’s been a long time since I’ve heard any mention of it tucked into conversations about contemporary news, sports and entertainment services, e.g., TuneIn, Pandora, etc. The Herb Tarleks of this world are an amazing breed of salespersons in that they have managed to sustain a client revenue to support about the same number of stations that existed in the late ‘50s. What happens after the sun goes down has never been a beautiful melody. All attempts to date to deal with ionospheric bounce have come to naught. There’s an old saying that a camel is really a horse designed by a committee, but the commissioners never give up trying to regulate natural law.
All that said, AM DXing is fun and a challenge for the few of us who have chosen to engage in it.
There are 4495 AM broadcasters trying to fit into 117 x 10 kHz wide channels. This does not include Canada or Mexico. For more USA detail https://www.fcc.gov/media/radio/am-query
Of those 246 are HD broadcasters in the AM band. It is interesting that WWFD Frederick, Md is not on the current HD list probably because it has an experimental licence. The nightime power is one tenth of its daytime power.
Has anyone heard WFAS all digital AM in White Plains New York 1230 kHz 1 kW?
WWFD Frederick is right down the road from me. It was apparently the first station to go digital, thus the signal is all hash on an AM-modulated radio. I have wondered just how many people have quoted what they heard on that station around the coffee machine each morning. After dark some AM-modulated stations break through. I wonder how the digital reception is then. Can I buy a digital radio at the mall?
The channel increment is 10 kHz. Stations are allowed to radiate ±10 kHz because AM has a pair of sidebands. Thus there is a 5 kHz overlap into the adjacent channels, which has been made worse because of improvements in the high frequency response of the studio chain particularly when broadcasting music.
Now to make things even worse there is HD radio. it is ±15 kHz wide in the hybrid AM mode. The analog AM signal audio bandwidth is halved producing ±5 kHz and there is a complete 10 kHz channel above and another 10 kHz channel below carrying the digital signal. These channels are used by other broadcasters. No wonder that HD radio in the AM band has such a bad reputation for interference. What happens to a pair of HD stations 10 kHz apart in adjacent coverage areas!!
There is a version of all digital HD radio which fits into a 10 kHz wide channel, which halves the bit rate to 20 kbit/s which gives speech quality audio with their old audio compression technology.
Very interesting article. Thank you !
Nightime MW BCB DXing typically favors directional antennas and/or phasing.
I am not big into MW listening, but I have had decent results with co-frequency broadcasters with an antenna phaser using a vertical and loop-on-ground.
https://www.hfunderground.com/board/index.php/topic,80208.msg264706.html#msg264706
Phasing out WBT 1100:
https://youtu.be/SgkZhl0IrKE
Phasing out the other station:
https://youtu.be/yK13MTGLTKU
Note that many HF phasing units tend to have a frequency limit that might not cover all or even any of the MW BCB bands. Mine drops out below ~1MHz. AFAIK, there are MW mods published for the popular MFJ HF antenna phasers.
“Because of this change in signal propagation from daytime to nighttime, if every AM station kept its daytime operating power at night, massive interference would result.” (Source: https://www.fcc.gov/media/radio/am-stations-at-night) Even this has never been much a help. A quick scan of the medium wave broadcast band will reveal a morass of mutual interference on almost every frequency, often with stations fading in and out. This is particularly the case along the Eastern US Seaboard. It’s gotten a lot worse over the decades as more stations stay on past daylight hours. The FCC goes on to say that new daytime licenses have ceased as of 1987. It would seen to me that this is exactly opposite of what should be done. The ultimate question is “how good is reception from local stations during nighttime hours”? The answer is not very good at all.