4 ms·

There are more hams in the US, and more active hams, than ever before. That's a funny sort of dying! Joe Taylor's work on below-the-noise signal extraction ha

by brians 8y ago

There are more hams in the US, and more active hams, than ever before. That's a funny sort of dying! Joe Taylor's work on below-the-noise signal extraction has revitalized shortwave: https://physics.princeton.edu/pulsar/k1jt/wsjtx.html https://physics.princeton.edu/pulsar/k1jt/wsjtx.html , particularly at the nadir of the sunspot cycle. That's a funny sort of dying! Amateur satellites are accessible for $100 in parts: https://www.n2yo.com/satellites/?c=18 https://www.n2yo.com/satellites/?c=18 ; with the same parts and some practice and luck you can talk to the space station. That's cool for anyone but especially cool for students; NASA will do more amateur radio work in 2018 than in any previous year. That's a funny sort of dying! If encryption were permitted on amateur bands, I'd expect to see commercialization right quick—along the same lines as the PACTOR modems embraced by the long-duration recreational sailing community: https://www.cruisingworld.com/staying-connected-at-sea https://www.cruisingworld.com/staying-connected-at-sea

prolikewh0a 8y ago
I've actually seen my young amateur radio communities die off during this new solar minimum, and a lot of my friends sold their expensive equipment. You really need money and space right now unless you want to sit at your desk and do some of the new low SNR "can talk to the mars rover with a wet sock as an antenna" modes that a lot of people don't like because it's too easy and poses no challenge. There's also VHF/UHF, but that's mostly older clique's. It's definitely a slowly dying hobby.
- madengr 8y ago
  You should be able to talk to anyone in the USA with 100W and a wire antenna. I think the bigger issue is noise in urban areas. The FCC does a shit job of regulating noisy equipment. I had to go through my house and dispose of certain Ethernet switches, an audio device, notebook power supply, etc.
trothamel 8y ago
Is there a good description of what those $100 in parts for satellite work are? Or better yet, something purchasable that's likely to work? I've been wanting to get into it, but I've never found a really accessible guide to getting started in satellite communication.
- lb1lf 8y ago
  I haven't looked into satellite work in fifteen years or so, but back then it was definitely possible to work the LEO FM repeater satellites using a handheld and a small yagi - typically two elements 144MHz, five on 432MHz if memory serves. With handhelds being dirt cheap and a yagi cut from a measuring tape being an option, I don't think getting on satellite for $100 sounds undoable.
- DerekRobot 8y ago
  You could make a good tape measure yagi and use it with a cheap radio like the UV-5R. It needs to be dual-band (440mhz and 2m); AMSATs are usually duplex. http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm
- brians 8y ago
  Sure! To talk to a satellite you need an antenna, a receiver, a transmitter, and maybe a computer—not for voice, but for text modes. Arrow will sell you a great antenna: http://www.arrowantennas.com/arrowii/146-437.html http://www.arrowantennas.com/arrowii/146-437.html , or you can google "tape measure yagi" and build an okay antenna. Then you can get the transmitter and receiver together, in a package like the regrettable BaoFeng UV-5R: https://www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/dp/B007H4VT7A https://www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/dp/B00... . This is a terrible radio. Their quality control is so bad that you sometimes commit a federal offense by pressing the transmit button—and for $100, you can't afford the test equipment to tell! So maybe use it as the receiver in a two-radio setup, and transmit with something like a Wouxun KG-UV9D. A Kenwood TH-D72A is an excellent choice to do the transmitter and receiver jobs, but hundreds of dollars. A Yaesu FT-60 is a great choice too, but it won't have full duplex—so you can't be sure your signal is getting out without help. To listen to a satellite you need even less: a crappy antenna and an RTL2832 USB software-designed radio: https://www.adafruit.com/product/1497 https://www.adafruit.com/product/1497 For all of these, you'll end up wanting miscellaneous coaxial cable and a bunch of ends. Hams tend to build up a library of crimpers and spare ends and such, so look to borrow from a friend or a club as you get started. The 75 Ω cable that's ubiquitous for television signals will totally work, but you'll have much less loss and much much less stress on components if you buy 50 Ω cable. Why not try the tutorial at https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/ https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weat... ? If that works, you can expand from there: the tutorial teaches you a huge amount about aiming at satellites and the physical work necessary to capture signals from space.
emptybits 8y ago
> There are more hams in the US, and more active hams, than ever before I apologize for repeating the doom and gloom then, because I know it can be self-fulfilling. The AARL has optimism but it also tells us net licenses are up <1% per year and "the large number of Baby Boomers will soon be aging off the licensee rolls", predicting "a significant decline in the number of hams, unless we take steps to reverse it." Source: http://www.arrl.org/news/more-than-30-000-new-ham-licensees-and-7-000-amateur-radio-exam-sessions-in-2017 http://www.arrl.org/news/more-than-30-000-new-ham-licensees-... A decentralized, no-carrier/ISP, disaster-tolerant medium for private communication would be amazing. I am not a licensed ham so this question is naive: If the major concern of allowing private communication over amateur bands is an influx of private commercial communication, then could bandwidth limits, protocols, signatures (amateur-vs-commercial), and enforcement be worth at least a trial? Perhaps on a new or limited existing band? A government-run experiment to address demand for this limited public resource seems reasonable.
- janoc 8y ago
  If you want that, there are plenty of ISM bands and loads of cheap equipment you can use to build such "decentralized, no-carrier/ISP, disaster-tolerant medium for private communication" (aka internet ...) HAM radio bands are meant for R&D work, learning and basically hobby stuff, not to replace internet or phone services - in fact, the regulations explicitly forbid such use.
  - mmirate 8y ago
    Then why is it the hams from whom we hear about such feats as "ionosphere skipping", and not any makers of 2.4GHz equipment?
    - brians 8y ago
      Well, in part because the maximum usable frequency of the ionosphere tops out around 30-60 MHz?
      - 8y ago
ColanR 8y ago
Anyone else get a certificate error on the princeton website?

by brians 8y ago

prolikewh0a 8y ago

I've actually seen my young amateur radio communities die off during this new solar minimum, and a lot of my friends sold their expensive equipment. You really need money and space right now unless you want to sit at your desk and do some of the new low SNR "can talk to the mars rover with a wet sock as an antenna" modes that a lot of people don't like because it's too easy and poses no challenge. There's also VHF/UHF, but that's mostly older clique's. It's definitely a slowly dying hobby.

madengr 8y ago
You should be able to talk to anyone in the USA with 100W and a wire antenna. I think the bigger issue is noise in urban areas. The FCC does a shit job of regulating noisy equipment. I had to go through my house and dispose of certain Ethernet switches, an audio device, notebook power supply, etc.

trothamel 8y ago

Is there a good description of what those $100 in parts for satellite work are? Or better yet, something purchasable that's likely to work? I've been wanting to get into it, but I've never found a really accessible guide to getting started in satellite communication.

lb1lf 8y ago
I haven't looked into satellite work in fifteen years or so, but back then it was definitely possible to work the LEO FM repeater satellites using a handheld and a small yagi - typically two elements 144MHz, five on 432MHz if memory serves. With handhelds being dirt cheap and a yagi cut from a measuring tape being an option, I don't think getting on satellite for $100 sounds undoable.
DerekRobot 8y ago
You could make a good tape measure yagi and use it with a cheap radio like the UV-5R. It needs to be dual-band (440mhz and 2m); AMSATs are usually duplex. http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm
brians 8y ago
Sure! To talk to a satellite you need an antenna, a receiver, a transmitter, and maybe a computer—not for voice, but for text modes. Arrow will sell you a great antenna: http://www.arrowantennas.com/arrowii/146-437.html http://www.arrowantennas.com/arrowii/146-437.html , or you can google "tape measure yagi" and build an okay antenna. Then you can get the transmitter and receiver together, in a package like the regrettable BaoFeng UV-5R: https://www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/dp/B007H4VT7A https://www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/dp/B00... . This is a terrible radio. Their quality control is so bad that you sometimes commit a federal offense by pressing the transmit button—and for $100, you can't afford the test equipment to tell! So maybe use it as the receiver in a two-radio setup, and transmit with something like a Wouxun KG-UV9D. A Kenwood TH-D72A is an excellent choice to do the transmitter and receiver jobs, but hundreds of dollars. A Yaesu FT-60 is a great choice too, but it won't have full duplex—so you can't be sure your signal is getting out without help. To listen to a satellite you need even less: a crappy antenna and an RTL2832 USB software-designed radio: https://www.adafruit.com/product/1497 https://www.adafruit.com/product/1497 For all of these, you'll end up wanting miscellaneous coaxial cable and a bunch of ends. Hams tend to build up a library of crimpers and spare ends and such, so look to borrow from a friend or a club as you get started. The 75 Ω cable that's ubiquitous for television signals will totally work, but you'll have much less loss and much much less stress on components if you buy 50 Ω cable. Why not try the tutorial at https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/ https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weat... ? If that works, you can expand from there: the tutorial teaches you a huge amount about aiming at satellites and the physical work necessary to capture signals from space.

emptybits 8y ago

> There are more hams in the US, and more active hams, than ever before I apologize for repeating the doom and gloom then, because I know it can be self-fulfilling. The AARL has optimism but it also tells us net licenses are up <1% per year and "the large number of Baby Boomers will soon be aging off the licensee rolls", predicting "a significant decline in the number of hams, unless we take steps to reverse it." Source: http://www.arrl.org/news/more-than-30-000-new-ham-licensees-and-7-000-amateur-radio-exam-sessions-in-2017 http://www.arrl.org/news/more-than-30-000-new-ham-licensees-... A decentralized, no-carrier/ISP, disaster-tolerant medium for private communication would be amazing. I am not a licensed ham so this question is naive: If the major concern of allowing private communication over amateur bands is an influx of private commercial communication, then could bandwidth limits, protocols, signatures (amateur-vs-commercial), and enforcement be worth at least a trial? Perhaps on a new or limited existing band? A government-run experiment to address demand for this limited public resource seems reasonable.

janoc 8y ago
If you want that, there are plenty of ISM bands and loads of cheap equipment you can use to build such "decentralized, no-carrier/ISP, disaster-tolerant medium for private communication" (aka internet ...) HAM radio bands are meant for R&D work, learning and basically hobby stuff, not to replace internet or phone services - in fact, the regulations explicitly forbid such use.
- mmirate 8y ago
  Then why is it the hams from whom we hear about such feats as "ionosphere skipping", and not any makers of 2.4GHz equipment?
  - brians 8y ago
    Well, in part because the maximum usable frequency of the ionosphere tops out around 30-60 MHz?
    - 8y ago

ColanR 8y ago

Anyone else get a certificate error on the princeton website?