Tag Archives: RFI

Radio Waves: AM Buzzkill, AM FEMA Push, AM Devitalization, and RFI-Blocking Chips

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!

Many thanks to SWLing Post contributors Rich Dalton and Dennis Dura for the following tips:


The JacoBLOG Junk Drawer – The AM Radio Edition (Jacobs Media Strategies)

Is there a bigger buzzkill blog topic than AM radio?

In a an era where digital has transformed radio broadcasting’s content and revenue focus, the last thing anyone wants to talk about in 2023 is lowly AM radio. But like that old drunk uncle who shows up at the reunion, AM is still part of the radio family.

In its heyday, AM ruled the radio roost. It wasn’t until the late 70’s when FM surpassed AM in total listening, and later profitability. Before then, AM was the behemoth. And the biggest and best in class could be magically heard in dozens of states each night. Weather, atmospherics, and bodies of water all factored into AM reception.

Many Baby Boomers vividly recall laying in bed at night, precariously tuning in a faraway AM station carrying a ballgame or even broadcasting progressive music. Or grabbing a portable transistor radio – like the one sitting in our junk drawer – taking it to a sporting event and having a great audio soundtrack from legends like Vin Scully, Ernie Harwell, or Jack Buck. [Continue reading…]

Former FEMA Leaders Continue Push for AM Preservation (Radio World)

Say the removal of AM radios from cars is “a grave threat to future local, state and federal disaster response and relief efforts”

The laundry list of current and former government officials advocating for the safeguarding of AM radio in electric vehicles continues to grow.

On Feb. 26, seven former leaders of the Federal Emergency Management Agency penned a letter to Secretary Pete Buttigieg of the Department of Transportation advocating for the preservation of the senior band and urging regulators to take action to protect the nation’s public safety.

“Because of the great distances that its signal carries, and due to its resiliency during even the worst natural disasters, the success of the National Public Warning System hinges on the use of AM radio,” the collective of former FEMA leaders wrote. “However, should EV makers continue removing AM radios from their vehicles, this vital public safety system will no longer function as intended.”

The dialogue between automakers and AM advocates has grown signficiantly in recent weeks. As we reported earlier, the Alliance for Automotive Innovation sent a reply to Sen. Ed Markey after he asked individual car companies about their commitment to broadcast AM radio in electric and other future vehicles. In the days following, Markey, the alliance, the National Association of Broadcasters and, now, FEMA officials and and an FCC commissioner have continued a public discourse.[Continue reading…]

AM Devitalization (All Access)

Been to a shopping mall lately?

It’s not pretty. Vacancies dot even the most successful malls. The lesser malls feel abandoned, like modern ruins, isolated and scary. One mall near us is so barren, they’ve marked off part of one end and use it for pickleball. Even the mall walkers are gone. If a mall can’t draw mall walkers in South Florida, that’s a harbinger of doom.

The reasons that big indoor malls aren’t thriving anymore aren’t a secret. Habits changed. Tastes changed. People shop online now, or go to discounters like Walmart or Target. Department stores have fallen out of favor. Teens don’t hang out in the food court anymore; they’re congregating on TikTok. What’s left are traditionalist shoppers who want to try stuff on or handle it before buying, or people who want to see stuff in person before firing up the Amazon app and buying it there. Other than Apple stores and a few other chains with loyal customers, there’s not a lot to draw people to the mall anymore, and what’s left is kinda creepy. Some malls are now mostly occupied by local businesses trying to make a go of it, and things like gyms and churches and DMV offices. I got my Florida driver’s license in a half-repurposed mall. It was strange. [Continue reading…]

Boffins concoct interference-busting radios (The Register)

Radio interference can be a pain to deal with, regardless of whether it’s a rogue baby monitor interrupting your Wi-Fi or a stadium full of smartphone signals drowning each other out.

However, brainiacs at MIT say they’ve developed a radio chip that can see through the noisiest RF hellscape by actively blocking unwanted frequencies before they can scramble messages.

The chip was developed to address the growing challenges associated with 5G and other wireless communications standards. It takes inspiration from several adjacent domains – including digital signal processing and applied electronics – explained Negar Reiskarimian, assistant professor of electrical engineering and computer science at MIT.

The work, presented at the International Solid-State Circuits Conference (ISSCC) last week and detailed in a recent blog post, combines a number of existing technologies into a novel radio chip, which researchers say can contend with RF interference 40 times higher than existing wideband receivers. What’s more, they say the method doesn’t require large, bulky filtering equipment.

Even in its current development stage, the chip is small enough – just 0.65mm square – for use in mobile devices, according to Reiskarimian and Soroush Araei, an MIT grad student working on the project. And while 5G is highlighted as a potential application for radios based on the design, they note there’s no reason it can’t be used for other wireless signals like Wi-Fi. [Continue reading…]


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Resource for tracking down sources of PV system RFI

Photo by Vivint Solar

Many thanks to SWLing Post contributor, Jerome van der Linden, who writes:

Hello Thomas,

In asking the manufacturer of the inverter for the solar array on our house what I might be able to do to reduce the EMI coming out of it, he gave me some Googling ideas, which led me to the following article which I think is worth passing on to others:

https://www.solar-electric.com/learning-center/reducing-electromagnetic-interference-pv-systems.html/

I was particularly interested in the sentence: Conversely, inverters connect to AC circuits in the home, turning every inch of the house wiring into an antenna that radiates the interference.

The guy who wrote the article has a lot of experience in chasing down this problem.

Cheers

Jerome van der Linden

Thanks for sharing this, Jerome. As more and more homes install solar solutions, tracking down sources RFI has certainly become an art form. When we installed our rather simple PV system over a decade ago, our installer stuck with telephony approved gear–charge controllers, etc. that are often used in communication central offices. 

Thank you for sharing!

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A little off-line, off-grid camping

You might have noticed a lack of posts this weekend and that would be because I was completely off-grid and off-line, camping with two good friends in Pisgah National Forest.

It was brilliant, actually. I got to hang with friends I’ve known for over 30 years, test my new one person backpack tent (a.k.a. the “Bear Burrito”–the one on the right above), and of course I played a bit of radio.

Black bears are a fact of life here in the mountains of western North Carolina and we spotted three hanging out within 25 meters of our campsite.

By the way: the trick when camping with bears? Don’t put food in your tent, else that whole “bear burrito” thing becomes a reality.

I had a fabulous time putting my Elecraft KX1 “Ruby” on the air. I made perhaps 15 contacts in CW (Morse Code) with 3 watts of power.

One of the cool things about the KX1 is you can change the mode to SSB and actually tune through several shortwave broadcast bands (if you have the three or four band version of the KX1). Of course, I had to do a little SWLing.

As I mentioned in my previous post, I’m also a proper coffee snob and I firmly believe coffee tastes better when brewed outdoors. Yesterday morning, I brewed a pot of Rock Creek French Roast.

Off-grid, off-line camping recharges my internal batteries and it’s for this reason, I’ll be doing a lot more this year with my family.

It’s is also a brilliant way to experience an environment without any forms of radio interference (QRM or RFI). If you want to do some proper DXing, take your radio on some primitive camping experiences. It’ll remind you what life was like before switching power supplies ruled the world!

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Radio Waves: BBC License Fee Frozen, Battling RFI, Warning to RTL-SDR Users in Ukraine, and WRD Special Broadcast

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!


BBC’s funding system under fire (Marketplace)

In the United Kingdom, you need a license to drive a car, fly a plane, practice medicine and watch TV.

The “TV license” is what Brits call their system for funding their world-famous broadcaster, the BBC. Currently, it costs the equivalent of $216 a year and is compulsory. Anyone in the U.K. caught watching or recording programs broadcast on any television channel or livestreamed on an online platform without a license is likely to be prosecuted.

The BBC — the Beeb, as it’s known — derives around $5 billion a year from this source. That’s 75% of the total revenue it needs to run a vast media empire, comprising 10 national TV channels and 10 national and 40 local radio stations as well as its World Service broadcasts and a global news website.

Full disclosure: The Beeb is a content partner for Marketplace.

But the license fee is under attack. The government just announced that it’s freezing the fee at the current level for two years and not increasing it in line with inflation — a decision that could cost the corporation nearly $400 million. The government has also hinted that it would like to eventually scrap the license fee altogether. [Continue reading at Marketplace…]

RF Interference (Nuts and Volts)

It’s everywhere! It’s everywhere! Fortunately, you can take a bite out of RFI.

RF interference — is it interference to you? Is it interference by you? Possibly both! What does this interference consist of? And how can you tell what type is present? A topic that starts off with so many questions is bound to cover a lot of ground, so let’s get started. Continue reading

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The conclusion to “Off the Shortwaves: Unhappy & Despondent”


From SWLing Post contributor, Troy Riedel:

I’d like to thank the SWLing Post Nation for their input re: my EMI/RFI issue (see: this previous post). It’s been a long 4-months and I’d like to share the results and outcome of my situation.

I will pick up where the last post ended and if anyone needs a review of the situation you can re-read the link to the original post in the previous paragraph.

At my expense, I hired an independent Master Electrician outside of the pool contractor. He and I reviewed everyone’s suggestions (I hope I’ve remembered to capture them all below but if not, rest assured it was fully explored and investigated). I have copied reader comments exactly as they left them back in October: Continue reading

Radio Waves: Eiffel Tower Radio 100 Years Ago, Raspberry Pi Radio Time Machine, Barrie ARC Thrives in Pandemic, and The Voice of Ganymede via JUNO

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 Dan Srebnick, the Southgate ARC and Geneva Witherspoon for the following tips:


Signal of strength: Eiffel Tower celebrates a centenary of radio broadcast (RFI)

A hundred years ago this week, France’s most famous landmark, the Eiffel Tower, was first used as an antenna for radio programmes. Looming high above the city’s uniform skyline, the tower was an obvious choice to pioneer public radio in France, proving the country’s prowess in broadcast technology.

On 22 December 1921, just three years after the end of WWI, “Radio Tour Eiffel” broadcast its first ever show, a live performance featuring legendary singers.

The trial was the beginning of a long series of broadcasts that continues today, with 45 television stations and 32 FM stations – including RFI – broadcasting from the Eiffel Tower.

According to the Lille-based publication Le Réveil du Nord of 24 December 2021, “a concert by wireless telephony took place at the Lille Theatre”.

Famous artists of that era, the legendary Sacha Guitry, the soprano Jeanne Hatto, the tenor Maurice Dutreix and others sang in a microphone in a room in the Eiffel Tower, from where it was broadcast to a “wireless phone set” in the hall of the Lille theatre.

“A large audience attended this session,” according to the dispatch. [Continue reading…]

Nostalgic Raspberry Pi Radio Tunes to Music From Past Decades (Tom’s Hardware)

The Raspberry Pi makes an excellent gift on its own, but getting one in a custom Time Machine Radio is remarkably fulfilling. This holiday, a maker known as Byte-rider created a custom Raspberry Pi Zero 2 W-powered radio for his father. Continue reading

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Off the Shortwaves: Unhappy & Despondent

Guest Post by Troy Riedel

Every radio enthusiast or ham operator knows this definition – something we all dread.  Electromagnetic interference – also known as radio-frequency interference when in the radio frequency spectrum – is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction (Source: Wikipedia).

I’ve been “off the shortwaves” (in fact, off ALL bands!) for a few weeks (a reminder to those who do not remember – I’m an SWL’er, I’m not a ham operator so I’m a listener only).  Here’s my story:

My house was built in 2004 thus the home’s electrical is “modern era”.  I’ve never, ever had a significant problem with RFI … except when the dishwasher is running (if it’s running, I have ZERO reception).

I didn’t want this (I acquiesced only in an attempt to become grandfather of the year), but an in-ground (vinyl liner) pool has been installed in my backyard (yeah, I’ve probably lost everyone’s sympathy with this statement).  If it’s any consolation, construction started long before the summer and won’t be fully completed until [hopefully] next Spring (and what’s left of my yard is a disaster zone and something that will cost a fortune to mitigate – maybe I’ve gained back just a little bit of sympathy?).

Pools are required to be bonded (the process by which the electrical and metallic components of the pool are joined together with a wire to form a non-resistive path between the components. The goal of bonding is to connect, contain and prevent the transmission of any harmful electrical voltage to pool equipment, people and pets).

I’m not an electrician, but essentially the pool is grounded by a copper wire … and a copper wire “ring” encircles the pool (now covered by the concrete pool deck).  The copper wire runs underground and resurfaces where the pump & filter are installed.  That copper bonding/grounding connects to the remote master switch at the pump & filter (pictured here – note where the copper line connects to and grounds the unit):

Electrical power line(s) run underground from the pump/filter area until resurfacing just outside the garage wall where they enter my home’s main breaker box inside the garage.

There is an unfinished electrical component.  A conduit was installed to add a pool light when the project is completed next Spring (see below), but at this point there’s nothing connected thus a “pool light” is not yet present.

Throughout the dig, installation of the steel walls, pouring the concrete bottom & steps, liner installation, the bonding, and covering the bonding “ring” with the concrete pool deck – all of this had zero negative effects on my SWLing.

Once the pool electrician connected power (connected the pump/filter) to the house, ALL radio bands were knocked out due to very extreme RFI.  All bands – the complete spectrum (choose your letters … AM/MW, FM, SW, VHF, UHF – all bands).

I’ve easily spent double-digit hours trying to isolate the EMI.  This is what I’ve done & discovered:

(1) Disconnected the pool grounding: no effect.

(2) [Only] Powered-off the two main breakers for the pool pump & filter: no effect (the pool equipment was tested, then the pool was winterized so nothing has been running).

(3) We used a handheld EMI detector over every inch of the interior and exterior of the house.  Yes, there are sources but nothing to the level that should cause a radio blackout.

(4) Turned off the main breaker, all power to the house: this is the only thing that eliminated the EMI/RFI.

(5) Multiple times, I’ve painstakingly turned-on one breaker at a time (isolating each circuit, on/off then proceeding to the next breaker).  I’ve found that for whatever reason, extreme RFI returns (and is present) on these three circuits: (upstairs) Master Bedroom (my Listening Post), the other upstairs bedrooms (combined on another circuit), and the (downstairs) Family Room circuit.  Note: Even if everything is unplugged on one of these circuits, just turning on the breaker introduces the extreme RFI (thus it must be coming from the breaker & not introduced from a device plugged-in).  Ferrite chokes have been installed on nearly everything plugged-in to outlets on the three “trouble” circuits.  I’m not saying the house was an RFI-free zone before the pool – but these three circuits only produced light-to-manageable RFI prior to the pool equipment being connected to the house’s main breaker box.  After 6000+ days of living in this house with no significant RFI issues, I’ve been in a complete radio blackout with very extreme RFI since the moment the live electrical line was connected between my pool pump/filter and my main breaker box.

And before you ask: No, there have not been any new electronics, no new devices, no new appliances, no LED lights, and all big screen TVs and other notorious RFI unfriendly devices are unplugged – nothing new has been plugged-in or added to the household except for the pool equipment.  There have been no new utilities in my area that could have caused a coincidental problem (no DSL, no fiber optic – nothing).  I cannot see how this situ could be caused by a neighbor, because the problem ceases when my power is off.  And “no”, I can’t move my Listening Post because even though the majority of the RFI is introduced over those three circuits, the entire house is impacted and it’s a complete radio blackout.

To reiterate, I had no radio-related problems during the entire construction (I listened to my radios as I pleased) and the problem did not start until the pool’s electrical line was connected to the main breaker.

Could the new wiring – at/inside the breaker box – be improperly shielded?  Could something be touching(?) that shouldn’t be?  Could something be loose inside the breaker box?  The three circuit breakers that are introducing the extreme RFI are in close proximity to each other in the breaker box and in close proximity to the two new pool breakers – could there be contamination from one to another?

I don’t make it a habit to play with electricity.  The pool company could frankly care less about my radio woes (it’s my problem, not theirs).  My power company supposedly checked their utility line coming into my house (I didn’t see them here, but they said the problem is not on their end).   And local electricians all essentially say, “[from their prospective] EMI sources are hard – if not impossible – to find”.

I have an electrician lined-up but we both thought it might be best to “put this out there” because someone may have an idea that he hasn’t thought of. Thus far, I’ve done almost everything myself that they stated they would do (minus opening-up the breaker box).  I’m hoping to solicit ideas from the SWLing Post Nation before I put the electrician on the clock.  And on the clock = $$$.

Thanks in advance for your input.  If I can’t get this mitigated, a liquidation event may be in my future.

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