8 ms·

Quindar Tones: the beeps heard in recordings of astronauts in space

172 points by NaOH 7y ago

NCG_Mike 7y ago
I know them as "roger beeps" from CB radio terminology.
- werdnapk 7y ago
  The exact tones were generated from Quindar manufactured equipment and would be specific to that equipment. So CB radio beeps wouldn't be Quindar tones.
  - dfox 7y ago
    Also the purpose is different. Quindar tones are intended to control intermediate equipment, while roger beep is meant as replacement for user saing "over" at the end of transmission.
    - ovi256 7y ago
      "Roger beeps" - a type of squelch tones - control intermediate equipment too, like amateur radio repeaters. See https://en.wikipedia.org/wiki/Squelch#Uses https://en.wikipedia.org/wiki/Squelch#Uses
      - dfox 7y ago
        The article mostly talks about CTCSS/DCS, which really are tones intended to control equipment, but these are mostly designed to not be audible (both CTCSS and DCS is sent during the whole transmission on frequencies below the voice pass band). Roger beep is a tone that is generated by the transmitting station when user lets go of the PTT (in similar way to Quindar outro tone). Using this tone to control anything in CB/HAM context is not really possible because there is essentially no standardization of how the beep sounds. Also IIRC having roger beep turned on is mostly frowned upon on ham bands.
        creeble 7y ago
        >Also IIRC having roger beep turned on is mostly frowned upon on ham bands. Except the Roger beep coming from the repeater, which is semi-important in that it denotes that the repeater has unlatched and the transmit timer is reset. If a repeater user keys up before hearing the Roger beep, the repeater doesn't restart the transmit timer, so there is a chance that your transmission will time out.
        geocrasher 7y ago
        Yes, CTCSS/DCS is a control tone. Definitely. The first HT I had had a CTCSS board added to it, and could only be set for a single tone! Things have changed since then. I've always thought that the beeps at the end of a user-initiated (not repeater) transmission would be cool, but they are indeed frowned upon. They aren't necessary, anyway. I'm sure if they became necessary for any reason, hams would be on the cutting edge. Interestingly a digital mode called JS8Call uses framed transmissions, linked together, to send text over HF. At the end of a frame set, an ascii diamond is transmitted to signify EOL. Otherwise the receiving station doesn't know if they are done, or if they dropped a frame, or what. Not audible of course.
peterhull90 7y ago
Does anyone know why they picked frequencies quite close together for the in/out tones (2525Hz/2475Hz) when the pass band for telephony was much wider?
- moonbug 7y ago
  so they could be removed with a single notch filter
- JshWright 7y ago
  Based on some quick Googling, it looks like the pass band they used for voice (at least for Apollo) was 300Hz to 2.3kHz. Assuming that filtering was being applied in the audio gear and the RF side of things was a bit more permissive, that would allow them to keep the control tones outside the range of any vox transmission.
- lb1lf 7y ago
  -Probably placed at the upper end of the passband so you could use a single high-pass filter in front of the detector to get rid of any noise on the line, easing detection. Also, if you wanted to remove the tones from the passband for some reason or other, you could do that with a single notch filter if the tones were sufficiently close.
bilekas 7y ago
> if NASA wanted to send control signals like transmit on and off, they’d need to run a whole parallel set of wires, which would be expensive. So, they came up with a solution: use the same lines for control signals as well! It really seems that in earlier years, when resources were limited, people really used their ingenuity far better than today. Maybe I have rose tinted glasses, but the level of creativity and cleverness seen in old solutions to problems/challenges just blows my mind all the time.
- VLM 7y ago
  Inband signalling was the way long distance trunk lines worked back in the MF signalling days decades before ISDN D channels and SS7 and all that. A fun topic to google for is what and how the 2600 Hz signal worked.
  - rusk 7y ago
    Didnt some guy figure out how to get free phone calls using a cheap whistle from a cereal box :-)
    - jasonjayr 7y ago
      Captain Crunch!
      - CapitalistCartr 7y ago
        John Draper https://en.m.wikipedia.org/wiki/John_Draper https://en.m.wikipedia.org/wiki/John_Draper
    - eskaytwo 7y ago
      And Wozniak had his blue boxes
    - dylan604 7y ago
      The book "Exploding The Phone" goes into all of these stories and much more. If you ever wanted to know about how and why the analog phone system was so hackable/phreakable, this book is for you. [0] http://explodingthephone.com/ http://explodingthephone.com/
ehosca 7y ago
i thought there were just fancy roger-beeps...
oldandcold 7y ago
I've always enjoyed these beeps...to me, for technical radio comms, they lend a sense of "tightness" or maybe even "seriousness" that normal comms don't have. Control purposes aside, I just love them. And until now, I had no idea they were different frequencies...now that I know this, I can tell.
jcrawfordor 7y ago
A somewhat similar system used in modern radio systems (well, radio systems that are now outdated, but still in widespread use) is two-tone sequential paging or the related QuikCall. These are in-band audio tones used to cause some receivers to open squelch as a form of selective calling. The method is predominantly used in public safety radio systems, where tone paging may be used to cause a fixed receiver in a station to open squelch (triggering an alarm) or cause a portable paging receiver (like a Motorola Minitor) to open squelch as a simple form of paging. Rural VFDs often rely on the latter to call out volunteers. Anyway, the world of in-band signaling in voice communications is really pretty interesting, and while digital systems have reduced the need for in-band there are still a lot of real-world systems that rely on it for compatibility with legacy equipment. The telephone system has largely moved on (except for various niche uses of DTMF) but in-band signaling is still pretty common in radio systems, where upgrading to a digital system is high cost and comes with its own limitations. Another example off-hand: most large-area public address systems, the type of thing the military often calls Giant Voice and might be used for tornado warning in some areas, use either DTMF or SelCall (five-tone) on the control radio channel (which in many cases is the same radio system used by public safety portable radios) to cause the loudspeakers to activate. A particular oddity of a lot of these systems is that they have different generations of receivers that use different methods, so sometimes you'll end up hearing the tones played aloud if a receiver opens squelch in reaction to something earlier in the sequence. And a last example, also usually seen in public safety - some radio schemes like MDC transmit a burst that sounds like a roger beep whenever the PTT is released, but is actually a short data packet that identifies the transmitting radio. This allows a specially equipped base station to show e.g. a dispatcher who was just transmitting. Sometimes the same signaling system is used to implement other features like 'man down' detection where a radio signals if it is not upright or has not moved for a period of time (common safety feature in fire departments), but sometimes these kinds of systems also just use a sample-based speech synthesizer if there's no digital system already in use. Oh, I can't resist one more. The "buzz," repeated three times, which proceeds emergency alert messages in the US is actually a short data packet which gives certain metadata about the alert and causes hardware in receiving radio stations (the system operates a bit like a "calling tree") to cut out the program audio and switch over the received alert. The two-tone beep which follows is a legacy system for the same purpose, although today no such receivers should still be in use. It's amusing that many phones use that two-tone signal as their ringtone for emergency alerts considering how divorced that is from its original purpose, but it's quite recognizable. Emergency alert messages should be followed by a three shorter data bursts which inform receivers that the alert is over. A closely related scheme is used by NOAA All-Hazards Radio to cause dedicated "weather emergency" receivers in people's homes to open squelch, these are more common in tornado-prone areas but generally work throughout the US. As the name suggests, All-Hazards also retransmits alerts from agencies other than NOAA including emergency alert system messages.
rkagerer 7y ago
Chatterer is my favorite mod for Kerbal Space Program, and it brings these tones (and other authentic sounds) to the game: https://forum.kerbalspaceprogram.com/index.php?/topic/83290-18x-chatterer-v0998-moar-talking-23-oct-2019/ https://forum.kerbalspaceprogram.com/index.php?/topic/83290-...
shmageggy 7y ago
When these tones are used in music, it instantly instills a sense of mystery and wonder. I don't know if it's something intrinsic to the sound, or if it's because of the recognizable context of exploration and discovery. One song that comes to mind is Satellite by BT, but I know I've heard it elsewhere too.
- kortex 7y ago
  I think it's the same reason I tear up uncontrollably watching rocket launches. It's just so epic and bigger than any one human. See also: overwatch effect. Here's a collection of songs: "I'm looking for songs that contain NASA radio transmission snippets, or a "space" theme conveyed in a creative manner. Examples in text" https://www.reddit.com/r/trance/comments/1vl39y/im_looking_for_songs_that_contain_nasa_radio/ https://www.reddit.com/r/trance/comments/1vl39y/im_looking_f...
  - shmageggy 7y ago
    Ah, yes Highroller by Crystal Method is one I've heard
- natalyarostova 7y ago
  Aphex twin #1 https://www.youtube.com/watch?v=z6xn0SRFYh4 https://www.youtube.com/watch?v=z6xn0SRFYh4
- yborg 7y ago
  I think these guys agreed with you... https://youtu.be/9Lt4Z5PYQPM https://youtu.be/9Lt4Z5PYQPM
- tonyarkles 7y ago
  There’s a song that comes up on Spotify once in a while that has, IIRC, clips of John Glenn during the Gemini missions. Chills down my spine.
asciimo 7y ago
> ...if NASA wanted to send control signals like transmit on and off, they’d need to run a whole parallel set of wires, which would be expensive. Why not transmit continuously? That seems to be the problem they're solving, but I'm not sure why that would be a problem.

172 points by NaOH 7y ago

NCG_Mike 7y ago

I know them as "roger beeps" from CB radio terminology.

werdnapk 7y ago
The exact tones were generated from Quindar manufactured equipment and would be specific to that equipment. So CB radio beeps wouldn't be Quindar tones.
- dfox 7y ago
  Also the purpose is different. Quindar tones are intended to control intermediate equipment, while roger beep is meant as replacement for user saing "over" at the end of transmission.
  - ovi256 7y ago
    "Roger beeps" - a type of squelch tones - control intermediate equipment too, like amateur radio repeaters. See https://en.wikipedia.org/wiki/Squelch#Uses https://en.wikipedia.org/wiki/Squelch#Uses
    - dfox 7y ago
      The article mostly talks about CTCSS/DCS, which really are tones intended to control equipment, but these are mostly designed to not be audible (both CTCSS and DCS is sent during the whole transmission on frequencies below the voice pass band). Roger beep is a tone that is generated by the transmitting station when user lets go of the PTT (in similar way to Quindar outro tone). Using this tone to control anything in CB/HAM context is not really possible because there is essentially no standardization of how the beep sounds. Also IIRC having roger beep turned on is mostly frowned upon on ham bands.
      - creeble 7y ago
        >Also IIRC having roger beep turned on is mostly frowned upon on ham bands. Except the Roger beep coming from the repeater, which is semi-important in that it denotes that the repeater has unlatched and the transmit timer is reset. If a repeater user keys up before hearing the Roger beep, the repeater doesn't restart the transmit timer, so there is a chance that your transmission will time out.
      - geocrasher 7y ago
        Yes, CTCSS/DCS is a control tone. Definitely. The first HT I had had a CTCSS board added to it, and could only be set for a single tone! Things have changed since then. I've always thought that the beeps at the end of a user-initiated (not repeater) transmission would be cool, but they are indeed frowned upon. They aren't necessary, anyway. I'm sure if they became necessary for any reason, hams would be on the cutting edge. Interestingly a digital mode called JS8Call uses framed transmissions, linked together, to send text over HF. At the end of a frame set, an ascii diamond is transmitted to signify EOL. Otherwise the receiving station doesn't know if they are done, or if they dropped a frame, or what. Not audible of course.

peterhull90 7y ago

Does anyone know why they picked frequencies quite close together for the in/out tones (2525Hz/2475Hz) when the pass band for telephony was much wider?

moonbug 7y ago
so they could be removed with a single notch filter
JshWright 7y ago
Based on some quick Googling, it looks like the pass band they used for voice (at least for Apollo) was 300Hz to 2.3kHz. Assuming that filtering was being applied in the audio gear and the RF side of things was a bit more permissive, that would allow them to keep the control tones outside the range of any vox transmission.
lb1lf 7y ago
-Probably placed at the upper end of the passband so you could use a single high-pass filter in front of the detector to get rid of any noise on the line, easing detection. Also, if you wanted to remove the tones from the passband for some reason or other, you could do that with a single notch filter if the tones were sufficiently close.

bilekas 7y ago

> if NASA wanted to send control signals like transmit on and off, they’d need to run a whole parallel set of wires, which would be expensive. So, they came up with a solution: use the same lines for control signals as well! It really seems that in earlier years, when resources were limited, people really used their ingenuity far better than today. Maybe I have rose tinted glasses, but the level of creativity and cleverness seen in old solutions to problems/challenges just blows my mind all the time.

VLM 7y ago
Inband signalling was the way long distance trunk lines worked back in the MF signalling days decades before ISDN D channels and SS7 and all that. A fun topic to google for is what and how the 2600 Hz signal worked.
- rusk 7y ago
  Didnt some guy figure out how to get free phone calls using a cheap whistle from a cereal box :-)
  - jasonjayr 7y ago
    Captain Crunch!
    - CapitalistCartr 7y ago
      John Draper https://en.m.wikipedia.org/wiki/John_Draper https://en.m.wikipedia.org/wiki/John_Draper
  - eskaytwo 7y ago
    And Wozniak had his blue boxes
  - dylan604 7y ago
    The book "Exploding The Phone" goes into all of these stories and much more. If you ever wanted to know about how and why the analog phone system was so hackable/phreakable, this book is for you. [0] http://explodingthephone.com/ http://explodingthephone.com/

ehosca 7y ago

i thought there were just fancy roger-beeps...

oldandcold 7y ago

I've always enjoyed these beeps...to me, for technical radio comms, they lend a sense of "tightness" or maybe even "seriousness" that normal comms don't have. Control purposes aside, I just love them. And until now, I had no idea they were different frequencies...now that I know this, I can tell.

jcrawfordor 7y ago

A somewhat similar system used in modern radio systems (well, radio systems that are now outdated, but still in widespread use) is two-tone sequential paging or the related QuikCall. These are in-band audio tones used to cause some receivers to open squelch as a form of selective calling. The method is predominantly used in public safety radio systems, where tone paging may be used to cause a fixed receiver in a station to open squelch (triggering an alarm) or cause a portable paging receiver (like a Motorola Minitor) to open squelch as a simple form of paging. Rural VFDs often rely on the latter to call out volunteers. Anyway, the world of in-band signaling in voice communications is really pretty interesting, and while digital systems have reduced the need for in-band there are still a lot of real-world systems that rely on it for compatibility with legacy equipment. The telephone system has largely moved on (except for various niche uses of DTMF) but in-band signaling is still pretty common in radio systems, where upgrading to a digital system is high cost and comes with its own limitations. Another example off-hand: most large-area public address systems, the type of thing the military often calls Giant Voice and might be used for tornado warning in some areas, use either DTMF or SelCall (five-tone) on the control radio channel (which in many cases is the same radio system used by public safety portable radios) to cause the loudspeakers to activate. A particular oddity of a lot of these systems is that they have different generations of receivers that use different methods, so sometimes you'll end up hearing the tones played aloud if a receiver opens squelch in reaction to something earlier in the sequence. And a last example, also usually seen in public safety - some radio schemes like MDC transmit a burst that sounds like a roger beep whenever the PTT is released, but is actually a short data packet that identifies the transmitting radio. This allows a specially equipped base station to show e.g. a dispatcher who was just transmitting. Sometimes the same signaling system is used to implement other features like 'man down' detection where a radio signals if it is not upright or has not moved for a period of time (common safety feature in fire departments), but sometimes these kinds of systems also just use a sample-based speech synthesizer if there's no digital system already in use. Oh, I can't resist one more. The "buzz," repeated three times, which proceeds emergency alert messages in the US is actually a short data packet which gives certain metadata about the alert and causes hardware in receiving radio stations (the system operates a bit like a "calling tree") to cut out the program audio and switch over the received alert. The two-tone beep which follows is a legacy system for the same purpose, although today no such receivers should still be in use. It's amusing that many phones use that two-tone signal as their ringtone for emergency alerts considering how divorced that is from its original purpose, but it's quite recognizable. Emergency alert messages should be followed by a three shorter data bursts which inform receivers that the alert is over. A closely related scheme is used by NOAA All-Hazards Radio to cause dedicated "weather emergency" receivers in people's homes to open squelch, these are more common in tornado-prone areas but generally work throughout the US. As the name suggests, All-Hazards also retransmits alerts from agencies other than NOAA including emergency alert system messages.

rkagerer 7y ago

Chatterer is my favorite mod for Kerbal Space Program, and it brings these tones (and other authentic sounds) to the game: https://forum.kerbalspaceprogram.com/index.php?/topic/83290-18x-chatterer-v0998-moar-talking-23-oct-2019/ https://forum.kerbalspaceprogram.com/index.php?/topic/83290-...

shmageggy 7y ago

When these tones are used in music, it instantly instills a sense of mystery and wonder. I don't know if it's something intrinsic to the sound, or if it's because of the recognizable context of exploration and discovery. One song that comes to mind is Satellite by BT, but I know I've heard it elsewhere too.

kortex 7y ago
I think it's the same reason I tear up uncontrollably watching rocket launches. It's just so epic and bigger than any one human. See also: overwatch effect. Here's a collection of songs: "I'm looking for songs that contain NASA radio transmission snippets, or a "space" theme conveyed in a creative manner. Examples in text" https://www.reddit.com/r/trance/comments/1vl39y/im_looking_for_songs_that_contain_nasa_radio/ https://www.reddit.com/r/trance/comments/1vl39y/im_looking_f...
- shmageggy 7y ago
  Ah, yes Highroller by Crystal Method is one I've heard
natalyarostova 7y ago
Aphex twin #1 https://www.youtube.com/watch?v=z6xn0SRFYh4 https://www.youtube.com/watch?v=z6xn0SRFYh4
yborg 7y ago
I think these guys agreed with you... https://youtu.be/9Lt4Z5PYQPM https://youtu.be/9Lt4Z5PYQPM
tonyarkles 7y ago
There’s a song that comes up on Spotify once in a while that has, IIRC, clips of John Glenn during the Gemini missions. Chills down my spine.

asciimo 7y ago

> ...if NASA wanted to send control signals like transmit on and off, they’d need to run a whole parallel set of wires, which would be expensive. Why not transmit continuously? That seems to be the problem they're solving, but I'm not sure why that would be a problem.