Tag Archives: Tubes

Radio Waves: Vacuum Tube Revival, KMJ Documentary, 2023 Domestic Broadcasting Survey, and Radio in Zimbabwe

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 Ulis Fleming, Dennis Dura, and Tracy Wood for the following tips:


One Man’s Quest to Revive the Great American Vacuum Tube (Wired)

The prized retro audio components are mostly manufactured in Russia and China. Now, a small Georgia company is rebooting US production.

ROSSVILLE, GEORGIA, ON the border with Tennessee, doesn’t look like a tech town. It’s the kind of place where homey restaurants promising succulent fried chicken and sweet tea are tucked among shuttered businesses and prosperous liquor stores. The cost of living is moderate, crime is high, politics are red, and the population has withered to 3,980.

But in the view of entrepreneur Charles Whitener, Rossville is the perfect place to stage a revival in US technology and manufacturing—albeit with a device that was cutting edge when the Ford Model A ruled the roads.

Whitener owns Western Electric, the last US manufacturer of vacuum tubes, those glass and metal bulbs that controlled current in electric circuits before the advent of the transistor made them largely obsolete. Tubes are still prized for high-end hi-fi equipment and by music gear companies such as Fender for their distinctive sound. But most of the world’s supply comes from manufacturers in Russia and China, which after the transistor era began in earnest in the 1960s helped sunset the US vacuum tube industry by driving down prices.

Whitener, a 69-year-old self-described inventor, vintage hi-fi collector, and Led Zeppelin fanatic, bought and revived AT&T’s shuttered vacuum tube business in 1995. The business has ticked along in the era of cheap overseas tubes primarily by serving the small market for vacuum tubes in premium hi-fi equipment with a model called the 300B, originally designed in 1938 to enable transoceanic phone calls. [Continue reading…]

KMJ | 100 Years in the Valley (Valley PBS on YouTube)

100 years is an incredible milestone for any business or organization! In this Valley PBS Original Documentary, we take you back in time as we explore the origins of KMJ as a conservative talk radio station as well as the long-lasting legacy and impact of their century-long run on the air and in the hearts & minds of their listeners.

Click here to view on YouTube.

2023 Edition of The Domestic Broadcasting Survey

Many thanks to SWLing Post contributor, Dennis Dura, who notes that the 2023 Edition of The Domestic Broadcasting Surve is available for download at:

http://www.dswci.org/dbs/

Many rely on radio broadcasts in Zimbabwe and across Africa (Northwest Arkansas Democrat Gazette via AP)

Many still rely on radio broadcasts for news, entertainment across continent

HARARE, Zimbabwe — Just the size of his hand, the radio set hung in the busy marketplace stall is essential to Mark Nyabanda.

“I can’t do without it,” said the 25-year old, taking a break from selling fertilizer in Mbare market in the capital, Harare, to listen to a radio weather report warning of possible floods.

Radio bulletins also provide him with information on disease outbreaks, political news and entertainment, he said.

“I don’t trust these new technologies,” he said, referring to social media. “They are full of falsehoods. We saw it during the coronavirus outbreak.”

In many Western countries, conventional radio has been overtaken by streaming, podcasts and on-demand content accessed via smartphones and computers.

But in many of Africa’s 54 countries, with a combined population of 1.3 billion people, traditional radio sets are widely used, highlighting the digital divide between rich countries and those still struggling to have reliable internet.

Radio sets are all over the place in Zimbabwe. Rural livestock herders dangle them from their necks while tending animals while those in the cities listen to their radio sets for news. [Continue reading…]


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High Speed A/D Conversion in 1965, with a Vacuum Tube!

Many thanks to SWLing Post contributor, Mark (AE2EA), with the Antique Wireless Museum who shares the following:

This isn’t a SWL, or even a ham radio story, but it’s a nice technology story about a vacuum tube at the beginning of the digital age and near the end of the tube age, that I thought you might be interested in:

Click here to view on YouTube.

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IEEE Spectrum: “The 11 Greatest Vacuum Tubes You’ve Never Heard Of”

Inside a transmitter at the Edward R. Murrow Transmitting Station.

Many thanks to SWLing Post contributor, Ed, who writes:

Hi Thomas, SWLing Post readers who are fans of tube radios might enjoy reading about “The 11 Greatest Vacuum Tubes You’ve Never Heard Of” in this IEEE Spectrum article. While only a few of them have been used in radio and audio applications, they’re all weird and amazing!

(Source: IEEE Spectrum)

In an age propped up by quintillions of solid-state devices, should you even care about vacuum tubes? You definitely should! For richness, drama, and sheer brilliance, few technological timelines can match the 116-year (and counting) history of the vacuum tube. To prove it, I’ve assembled a list of vacuum devices that over the past 60 or 70 years inarguably changed the world.

And just for good measure, you’ll also find here a few tubes that are too unique, cool, or weird to languish in obscurity.

Of course, anytime anyone offers up a list of anything—the comfiest trail-running shoes, the most authentic Italian restaurants in Cleveland, movies that are better than the book they’re based on—someone else is bound to weigh in and either object or amplify. So, to state the obvious: This is my list of vacuum tubes. But I’d love to read yours. Feel free to add it in the comments section at the end of this article.

My list isn’t meant to be comprehensive. Here you’ll find no gas-filled glassware like Nixie tubes or thyratrons, no “uber high” pulsed-power microwave devices, no cathode-ray display tubes. I intentionally left out well-known tubes, such as satellite traveling-wave tubes and microwave-oven magnetrons. And I’ve pretty much stuck with radio-frequency tubes, so I’m ignoring the vast panoply of audio-frequency tubes—with one notable exception.

But even within the parameters I’ve chosen, there are so many amazing devices that it was rather hard to pick just eleven of them. So here’s my take, in no particular order, on some tubes that made a difference.[]

Thank you for the tip, Ed. Brilliant article!

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Tubes and Valves: Dan’s research uncovers three vintage films

Hammarlund-SP-600

Many thanks to SWLing Post contributor, DanH, who writes:

I have been working on my Hammarlund SP600-JX-21 for the last two weeks. Results of the filter cap replacement were encouraging. I’m going after an AVC issue that is probably capacitor-related as well before doing a re-alignment with the signal generator.

All of this activity has turned my attention toward vacuum tubes. I found three vintage industrial films online that caught my interest…

The Mullard Radio Valve Company produced The Blackburn Story in 1962. The film was shot at what must have been close the peak of vacuum tube mass production. This presentation is unique in its finely detailed documentation of miniature tube construction. The hand labor required to build some of these tubes is incredible, considering it is a mass production operation. A surprising degree of automation is present for manufacture of some of the more popular tube types. The video resolution is not the best but I found myself ignoring this limitation after the film got underway. I have a few Mullard tubes in my tube boxes.

Click here to view on YouTube.

Western Electric presents A Modern Aladdin’s Lamp (1940). This look at the electron tube is hosted by none other than Lowell Thomas. From the age of four pin and octal base tubes animation shows how tubes work.

Click here to view on YouTube.

Electronics at Work (1943) is a WWII offering by Westinghouse. The description of vacuum tube technology is a little more detailed and again animation is employed for visual impact. A variety of vacuum tube applications in industry and the military are shown from curing plywood to producing X-rays. The excellent animation was contributed by Famous Studios (when they weren’t doing the wartime Popeye cartoons).

Click here to view on YouTube.

Wow–thanks for sharing these excellent videos, Dan!

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