Monthly Archives: May 2020

Quindar Tones: Those iconic NASA PTT confirmation beeps

Photo credits: NASA/Bill Ingalls

Yesterday, my family watched the successful launch of the NASA Demo-2 SpaceX Dragon via YouTube.

As astronauts Robert Behnken and Douglas Hurley communicated with Mission Control, we heard PTT confirmation beeps after each transmission.

Those beeps, of course, reminded me of past NASA missions and those iconic confirmation tones we heard in audio from the Mercury, Gemini, and Apollo days all the way into Space Shuttle missions.

Quindar Tones

Source: honeysucklecreek.net

Last year, after spending a couple of days at the US Space and Rocket Center (and attending the Huntsville Hamfest), I heard numerous NASA audio clips and that lead me down the path of researching those PTT confirmation tones.

Turns out, they’re called “Quindar Tones.”

I couldn’t find any information about Quindar Tones at the US Space and Rocket Center–although, admittedly, the place is massive and I could have easily overlooked it–so I did a little research when I returned home.

I found this archived post on the NASA’s Apollo Lunar Surface Journal wesbite:

Re: Apollo beeps

Journal Contributor Mark Burckhard writes:

“I’ve always wondered what purpose the ‘beeps’ served that one heard intermittently during the voice communications with the Command and Lunar Modules during the Apollo missions, as well as other space missions.”

Journal Contributor Mike Dinn provides an MP3 clip ( 123k ) from a network audio check that includes numerous quindar tones.

Journal Contributor Markus Mehring replies:

“‘Other space missions’ is quite an accurate observation, since the ‘beeps’, in fact, are still in use today on Shuttle flights, at least on the UHF frequencies.”

“These beeps are called ‘Quindar-Tones’. Their purpose is to trigger the ground station transmitters when there is an outgoing transmission from Earth. The CapCom in the Mission Control Center, who is taking care of communications with the crew, uses his communication gear in a PTT mode exclusively. ‘PTT’ is short for Push-To-Talk, which means that the CapCom presses a button every time and as long as he wants to talk. (The crews back during Apollo – and also today – usually communicate via PTT as well, but they also have the so-called ‘VOX mode’ at their disposal, in which their microphones are voice-triggered by a certain adjustable threshold volume levels. VOX is used when they don’t necessarily have their hands free.)

When the CapCom presses his PTT button to start a transmission, an intro tone (2.525KHz sine wave with a length of 250ms) is generated and triggers the ground station transmitters to send. And when he is finished talking and releases the button again, a slightly lower outro tone (2.475KHz, sine, 250ms) is generated to trigger the ground station transmitters to turn off. So in short, these are remote control trigger tones.

CU! Markus”

I then discovered this article via the Internet Archive Wayback Machine, which gave more detail about the Quindar Tones’ name and some of the idiosyncrasies of the system:

The story behind the “Beep”

Steve Schindler, an engineer with voice systems engineering at NASA’s Kennedy Space Center, offers the following history of [Quindar Tones] origins.

“Quindar tones, named after the manufacturer of the tone generation and detection equipment, are actually used to turn on and off, or “key,” the remote transmitters at the various tracking stations (Merritt Island Launch Area–now Kennedy Space Center, Bermuda, Australia, etc.) that were used to communicate with the Mercury through Apollo spacecraft and, in some cases, are still used with the Space Shuttle.”

[…]”Although it usually worked well, there were a couple of peculiarities with this system. If the transmitter was keyed and the telephone line connection broken, the transmitter would never get the tone to turn off. To prevent this there was a “transmitter on” light at each remote site that would come on when the transmitter was keyed. Someone was supposed to monitor the circuit and if the audio dropped, but the “transmitter on” light was still on, they would have to manually unkey the transmitter. Also, just before communications was handed over to a new tracking station, the key-unkey tone pair was sent 10 times to ensure that everything was functioning correctly. This was done before the audio was patched to the tracking station’s line so it wasn’t heard in the control room or on NASA Select audio.

The Quindar system was actually built from a piece of equipment that was used to put multiple teletype circuits on a single phone line by means of frequency domain multiplexing. Because replacement parts are no longer available, an “out-of-band signaling” system was installed in 1998 for the transmitters located in the U.S. This system uses a continuous tone that is below the normal audio frequency range. When the tone is present, the transmitters are keyed. When the tone is not present, the transmitters are unkeyed. It worked fine, but the Astronaut Office complained about the lack of tones which everyone had become accustomed to as an alert that a transmission was about to start. So, the Quindar tone generator, which was still installed in case it was necessary to key the transmitters at an overseas site, was re-enabled.

Even though you won’t hear the same Quindar tones in present-day space missions, you can listen until your heart is content at the website Apollo In Real Time.

The Internet Archive also has a massive collection of Apollo audio free to stream and download.

Quindar Music

If you’re fascinated with the NASA audio soundscape in general, you might check out the electronic music duo Quindar featuring longtime Wilco member Mikael Jorgensen, and art historian-curator James Merle Thomas.

Quindar: Mikael Jorgensen & James Merle Thomas. Photo by Chad Ress, Spacesuits by Cassandra C. Jones

Science Friday featured an extended interview with the group in 2017. If you love electronic music–especially if you’re a fan of Wilco, it’s well worth a listen:

Check out their latest video, Choco Hilton:

Speaking of Mikael Jorgensen and Wilco, I should note here that their album yankee hotel foxtrot has a deep shortwave motif.

Anyone else fascinated with Quindar Tones and NASA audio? Feel free to comment and share any other resources or projects you’ve found.

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Reunited with an old friend…

Super cheap Walmart soap bar holder transforms into an ideal portable radio stand

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Many thanks to SWLing Post contributor, Shawn Bliss (KB7WYO), who writes:

Hi, Thomas! I love the blog and check in every day or two to get my SWL fix. I recently purchased a PL-310ET on your recommendation (and those of many other radio people) and absolutely love it. My previous porch radio was a well-worn and filthy Grundig G8 Traveler II which of course suffered a broken kickstand soon after its purchase many years ago. Wanting to avoid the same problem with the 310, I figured I might be able to improvise a stand out of some household item, and a trip to a local big box store today proved extremely fruitful in that respect!

As I wandered through the kitchen accessories at Walmart, I spotted a little black sink caddy, typically used to hold a dish sponge and hang on a sink or faucet. I grabbed it, paid a little under four bucks for it, and took it home. It’s a cheap, lightweight, and adjustable stand for small to midsize radios.

The caddy is essentially a loop of flexible, bendable rubber-coated wire with a perforated rubber cradle for the sponge. Because it can be bent and shaped, it’s ideal for adjusting to different sized portables. In its default shape from the store, it held the 310ET, the G8, my Tivdio V-115, and other smaller items like my phone and e-reader.

I’m sure it could be bent to fit a PL-660, PL-880, Eton Satellit, XHDATA D-808, and other larger portables, all at adjustable back angles.

Best of all, the caddy can be bent down to fit into a go-bag or piece of travel luggage. I figure a fellow pack-nut like yourself would find this to be useful indeed!

These things are cheap and readily available at pretty much every Walmart, but I’ll post a link to the webpage for the Mainstays Flexible Sink Caddy. I hope this info is useful to other SWLs and hams. I instantly thought of the Post and your gear/accessory posts in the past when I saw it.

https://www.walmart.com/ip/Mainstays-Flexible-Sink-Caddy/480104340

What a great idea, Shawn! Since this soap bar holder is so flexible, it could be bent to hold radios at pretty much any angle. Next time I’m at Walmart, I’ll pick one up. Perhaps this is even available at Walmart stores in other countries since it’s sold under the Mainstays brand name.

I believe this holder could also serve as a stand for numerous portable QRP transceivers.

Thanks again for the amazing tip, Shawn!

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Radio Emma Toc World Service Schedule for June 2020

Radio Emma Toc World Service – Schedule Summary – June 2020

Ways to listen… Radio Emma Toc World Service – programme no. 2 – June 2020

You can listen online – www.emmatoc.com – visit the ‘World Service’ page.

You can listen to our shortwave or FM broadcasts via our relay partners as follows:

Happy listening! If you are outside the transmitter coverage areas, why not listen via the broadcasters’ online services. Website details for the above stations are listed on our own website here – www.emmatoc.org/worldserviceschedule

If you don’t have access to receivers & aerials you can try using an online SDR receiver – ve3sun.com/KiwiSDR – experience the enjoyment of tuning around shortwave from worldwide locations online.

We are happy to issue eQSLs for reception reports sent to – [email protected] – & will gladly include for online reports. If using an online SDR, please give us the SDR location.

Finally if any stations wish to relay our programme a download link is available on our website. Please advise us of times & dates so we can publicise in our schedule.

Thank you!

Jim Salmon – Radio Emma Toc

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Encore – Classical Music on Shortwave.

Radio Waves: Free Foundation License Course, More Titanic Radio, CQD, and ARRL Field Day Waivers

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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 Trevor, Mark Hirst and Ulis Fleming for the following tips:

Register now for free Amateur Radio Foundation Online training course (Southgate ARC)

The next free amateur radio Foundation Online training course run by volunteers from Essex Ham starts on Sunday, June 7

The Coronavirus outbreak and the RSGB’s introduction of online exams that can be taken at home has led to a surge in demand for free online amateur radio training courses such as that run by Essex Ham.

These courses have been very popular and early registration is advised. 313 people took the course that started on May 3 and a further 235 are on the course that started on May 17.

You can find out more about online training and register to join a course at
https://www.essexham.co.uk/train/foundation-online/

Essex Ham
https://www.essexham.co.uk/
https://twitter.com/EssexHam

US court grants permission to recover Marconi telegraph from Titanic wreckage (ARS Technica)

But NOAA is fiercely opposed to the controversial salvage mission.

When RMS Titanic struck an iceberg on April 14, 1912, crew members sent out numerous distress signals to any other ships in the vicinity using what was then a relatively new technology: a Marconi wireless telegraph system. More than 1,500 passengers and crew perished when the ship sank a few hours later. Now, in what is likely to be a controversial decision, a federal judge has approved a salvage operation to retrieve the telegraph from the deteriorating wreckage, The Boston Globe has reported.

Lawyers for the company RMS Titanic Inc.—which owns more than 5,000 artifacts salvaged from the wreck—filed a request in US District Court in Alexandria, Virginia, arguing that the wireless telegraph should be salvaged because the ship’s remains are likely to collapse sometime in the next several years, rendering “the world’s most famous radio” inaccessible. US District Judge Rebecca Beach Smith concurred in her ruling, noting that salvaging the telegraph “will contribute to the legacy left by the indelible loss of the Titanic, those who survived, and those who gave their lives in the sinking.”

However, the National Oceanic and Atmospheric Administration (NOAA) is fiercely opposed to the salvage mission. The agency argues in court documents that the telegraph should be left undisturbed, since it is likely to be surrounded “by the mortal remains of more than 1500 people.” Judge Smith countered in her decision that the proposed expedition meets international requirements: for instance, it is justified on scientific and cultural grounds and has taken into account any potential damage to the wreck.[…]

Why Titanic’s first call for help wasn’t an SOS signal (National Geographic)

When RMS Titanic set sail in 1912, it was blessed and cursed with the latest in communication technology—the wireless telegraph. In the last hours after Titanic hit an iceberg, radio messages sent from the storied sinking ship summoned a rescue vessel that saved hundreds of people, but also sowed confusion with competing distress calls and signal interference. More than 1,500 people died that fateful night.

Now, a recent court ruling may pave the way to the recovery of Titanic’s telegraph, designed by Guglielmo Marconi, a telecommunications pioneer and 1909 Nobel Prize winner in physics who invented the first device to facilitate wireless communications using radio waves.

[…]Despite the limitations of the Marconi telegraph—and the fact that it wasn’t intended to be used as an emergency device—Titanic was outfitted with a radio room and a Marconi-leased telegraph machine. Two young Marconi-employed operators, chief telegraphist Jack Phillips and his assistant Harold Bride, sent Morse code “Marconigrams” on behalf of Titanic’s well-heeled customers 24 hours a day during its maiden voyage in April 1912.

Both Marconi’s technology monopoly and the torrent of personal messages conveyed through Titanic’s telegraph proved fatal on that April night. Phillips was so overwhelmed by a queue of incoming and outgoing guest telegrams —one Titanic passenger wanted to “notify all interested” about an upcoming poker game in Los Angeles—that he didn’t pass on messages about the ice threatening Titanic’s ocean environs. When a nearby vessel, SS Californian, telegraphed that it was already surrounded by ice, Phillips testily responded “Shut up! I am busy.”

Once Titanic hit the iceberg, Phillips tone shifted and he used the Marconi distress signal: “CQD.”[…]

Temporary Rule Waivers Announced for 2020 ARRL Field Day (ARRL News)

With one month to go before 2020 ARRL Field Day, June 27 – 28, the ARRL Programs and Services Committee (PSC) has adopted two temporary rule waivers for the event:

1) For Field Day 2020 only, Class D stations may work all other Field Day stations, including other Class D stations, for points.

Field Day rule 4.6 defines Class D stations as “Home stations,” including stations operating from permanent or licensed station locations using commercial power. Class D stations ordinarily may only count contacts made with Class A, B, C, E, and F Field Day stations, but the temporary rule waiver for 2020 allows Class D stations to count contacts with other Class D stations for QSO credit.

2) In addition, for 2020 only, an aggregate club score will be published, which will be the sum of all individual entries indicating a specific club (similar to the aggregate score totals used in ARRL affiliated club competitions).

Ordinarily, club names are only published in the results for Class A and Class F entries, but the temporary rule waiver for 2020 allows participants from any Class to optionally include a single club name with their submitted results following Field Day.

For example, if Podunk Hollow Radio Club members Becky, W1BXY, and Hiram, W1AW, both participate in 2020 Field Day — Hiram from his Class D home station, and Becky from her Class C mobile station — both can include the radio club’s name when reporting their individual results. The published results listing will include individual scores for Hiram and Becky, plus a combined score for all entries identified as Podunk Hollow Radio Club.

The temporary rule waivers were adopted by the PSC on May 27, 2020.

ARRL Field Day is one of the biggest events on the amateur radio calendar, with over 36,000 participants in 2019, including entries from 3,113 radio clubs and emergency operations centers. In most years, Field Day is also the largest annual demonstration of ham radio, because many radio clubs organize their participation in public places such as parks and schools.

Due to the COVID-19 pandemic, many radio clubs have made decisions to cancel their group participation in ARRL Field Day this year due to public health recommendations and/or requirements, or to significantly modify their participation for safe social distancing practices. The temporary rule waivers allow greater flexibility in recognizing the value of individual and club participation regardless of entry class.

ARRL is contacting logging program developers about the temporary rule waivers so developers can release updated versions of their software prior to Field Day weekend. Participants are reminded that the preferred method of submitting entries after Field Day is via the web applet. The ARRL Field Day rules include instructions for submitting entries after the event. Entries must be submitted or postmarked by Tuesday, July 28, 2020.

The ARRL Field Day web page includes a series of articles with ideas and advice for adapting participation this year.[…]

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Christoph’s homebrew custom hotkey pad for SDR applications

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Last week, I saw a fascinating post by Christoph Jahn on the SDRplay Facebook page.

Christoph created a custom hotkey pad for use with SDRuno. The project is actually quite simple and his finished product looks amazing:

The steps involve downloading “LuaMacros” a freeware macros utility that allows you to map macros to an external USB device like a cheap numeric keypad. Christoph then designed the key templates and printed them on a strong adhesive vinyl foil.

I asked Christoph if I could post his project on the SWLing Post and he kindly sent me the followed PDF with step-by-step instructions.

Click here to download the instructions as a PDF (6.71MB).

Christoph also shared the macros file he used for his project (download .XML file 8.77 KB).

Thank you so much for sharing this, Christoph! Your finished product is so professional, I would have thought it was produced by SDRplay!

This could be a useful tool for a radio friend who is visually-impaired and, of course, could be compatible with a wide range of SDR apps and rig control software that allow keyboard shortcuts.

Readers: Have you done a similar project? Please comment with your experience and any details–especially noting applications and programs you find are compatible with keyboard shortcut mapping. This could be very beneficial for radio enthusiasts with disabilities!

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