Category Archives: Radio History

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!

Hamvention Find: Rare Hallicrafters SX-11

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Yesterday, at the Dayton Hamvention Flea Market, a Hallicrafters SX-11 caught my eye. I don’t often see the SX-11 in such excellent shape. The seller wanted $500–quite steep for a flea market find.

Then I noticed a plaque on the side of the cabinet.

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This Hallicrafters SX-11 has been in the seller’s family since Bill Halligan himself gave it as a gift in the mid 1930s.

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This is what I love about the flea market–you never know what you’ll find.

Radio connection: English city named after Maine relay station

RCA-Dial

Many thanks to SWLing Post contributor, Richard Cuff, who writes:

“Thought the blog might enjoy this…it’s actually longwave related more than SW, but I know you often include historical items in blog posts.”

Indeed I do, Richard! Thanks for sharing. Here’s an excerpt from the Bangor Daily News:

Former radio relay station in Houlton may lead to new connection to England

HOULTON, Maine — Rugby Radio Station, a radio transmission site in the United Kingdom that once had ties to this Aroostook County community as part of a transoceanic communications network in the 1930s, is being re-imagined as a new city in England that will be aptly named: Houlton.

Rugby Radio Station was a radio transmission facility near the town of Rugby, Warwickshire in England. From 1927 to 1957, Houlton served as a relay station for long-wave transoceanic transmissions between New York and London.

Located on the County Road, the Houlton site was decommissioned on Oct. 1, 1957. That property is home to Roger and Carol Hand.

James Scott, who is the director of planning and communication for Urban and Civic, a property development and investment company based in London, was in Houlton on April 29 to meet with town officials and local historians to get a better feel for the American community that will bear the namesake of the new development.

[…]The Rugby site, which will be renamed Houlton, is 1,100 acres and over the next 20 years it will be developed into 6,000 homes, three primary schools, one secondary school and 1 million square feet of commercial floor space.

“The radio station [in England] was in operation from 1926 until 2005,” Scott said. “The site is really interesting in that it is mainly open fields, with some very large buildings and 12 800-foot masts. It was a very emotive site for a lot of people, but it was not very well developed.”

The masts have all been torn down, but some of the buildings were preserved for historical purposes.

[…]In the early days of transoceanic transmissions, a crew of five individuals worked at the Houlton station from 5 a.m. to 8 p.m., according to a November 1957 article in Long Lines, a company magazine produced by employees of American Telephone and Telegraph. As demand for service increased, coverage was extended from 4 a.m. to midnight.

Houlton was chosen as the relay station because the signal could not reach all the way from England to New York directly. The local site did not have massive antennae reaching upward such as the location in England. Instead, the transmission lines here were placed horizontally and stretched for many miles.

By the mid-1930s, long-wave transmissions declined because of technological improvements in short-wave radios. The Houlton site was also used in the 1940s as a ship-to-shore service.

Read the full article, at the Bangor Daily News site.

From the BBC Archives: The first 21 years of the World Service

BBC-AT-WAR

Many thanks to SWLing Post contributor, Andrea Borgnino, who shares a link to the excellent archived radio documentary, The first 21 years of the World Service, via the BBC World Service‘s online audio archives.

The recording/broadcast dates from December, 18 1953. Here’s the description of the recording:

The first 21 years of the World Service: how it began in 1938, its important role in WW2 and its aftermath, including historic moments as they were first broadcast by Churchill, de Gaulle, Eisenhower.

Click here to listen to the documentary via the BBC World Service.

VOG Interval Signal

I learned an interesting fact in this documentary: I had no idea that the BBC used the Greek radio interval signal for their Greek language service while Greece was occupied in WWII. After liberation, the BBC Director General “solemnly” handed the famous interval signal–“the sound of shepherds’ pipes mingling with the bells of their flocks”–back to Greece. Amazing.

The Greek radio interval signal is one of my all-time favorites. Indeed, my mobile phone’s ringtone is the VOG interval signal:

If you would like to add this ringtone to your mobile phone, check out this post from 2013.

SIGSALY and the unlikely history of the Bell Labs Voder

SIGSALY

One of my favorite podcasts, 99% Invisible, recently featured a story on the Bell Labs’ Voder and how its innovation lead to one of the best kept secrets in WWII high frequency communications: SIGSALY.

The episode is called Vox Ex Machina and, trust me, it’s a gem.

Stop whatever you’re doing today and listen to this brilliant little documentary.

I’ve embedded the SoundCloud audio of the episode above, but you can also listen via the 99 Percent Invisible website.