Ham radio operators receive signals from Voyager 1 on Dwingeloo telescope

Original Article ↗ Hacker News Discussion ↗

Amateur radio enthusiasts using the historic 25 m Dwingeloo radio telescope in the Netherlands have managed to receive the carrier signal from NASA’s Voyager 1 probe, now nearly 25 billion kilometers from Earth. Commenters explore how such weak deep-space signals can still be detected—touching on dish size, signal-to-noise techniques, Doppler correction, and the vastly greater power and infrastructure of NASA’s Deep Space Network needed to actually communicate with the probe. The thread also veers into related topics such as antenna physics, frequency publishing practices, and the origins and correct styling of the term “ham” radio.

Big radio dishes and power

  • Commenters marvel at large dishes like Dwingeloo and Arecibo and their enormous effective isotropic radiated power (EIRP), with Arecibo cited as having a 22 TW-equivalent beam.
  • Clarifications: a dipole is not isotropic (has ~2.15 dB gain over isotropic), and even huge dishes aren’t perfect shields; backlobes exist but are heavily attenuated.
  • Some curiosity about near‑field effects and comparisons to high‑power lasers.

Receiving vs. communicating with Voyager 1

  • Dwingeloo’s team emphasizes they can receive only Voyager’s carrier, not communicate; DSN’s 70 m dishes and specialized equipment are required for uplink.
  • Several see this as preempting “can you hack it?” questions; others stress that practical limits are dish size, power, and legal constraints.
  • Discussion that Voyager’s exact frequencies have been partially de‑emphasized online since the Ukraine war, but are still easily discoverable; satellite hobbyists routinely find and share them.

Signal strength, SNR, and detection

  • People are surprised any positive SNR is possible at ~25 billion km.
  • Others note you can decode signals at negative SNR using long integration and narrow bandwidth; modern DSP makes this practical.
  • One participant involved with the observation explains:
    • Live plots use 1 Hz bins, averaged over 2–3 minutes to lower noise.
    • Only the narrowband carrier is visible; modulation/data look like noise at this setup.
    • About 25% of Voyager’s power is in the carrier at this data rate.
  • Debate over whether ever‑more‑sensitive, distributed receivers could recover very distant broadcasts runs into the fundamental issue that both signal and noise increase; at some distance everything sinks into the noise floor.

Terminology and naming debates

  • Multiple comments insist “ham” is not an acronym; capitalization “HAM” is seen as a tell that someone is not an operator.
  • Others share folk etymologies and point to a detailed Wikipedia article on the term.
  • Side debates over “satellite” vs. “probe” for Voyager, and assorted acronym/word confusions (MAC, ELO, Lua, etc.).

Dwingeloo and other telescopes

  • Visitors describe Dwingeloo as remote (to reduce interference) yet publicly accessible, used today mainly by volunteers and amateurs.
  • Its age is seen as impressive given continued functionality; contrasted with Arecibo’s collapse.
  • There’s curiosity about the added 8.4 GHz antenna but no technical details in the thread.

Deep Space Network locations

  • Some note the geographic spacing of DSN sites (Madrid, Canberra, Goldstone) and wonder why Western Australia wasn’t chosen instead of Canberra.
  • Others mention local Australian facilities (e.g., Pine Gap, Geraldton) and the ease of visiting the Canberra complex.

Sense of scale and misc

  • Many express awe that Voyager is over a light‑day away and beyond the heliopause.
  • A link is shared to a separate blog where Voyager 1 telemetry has been fully decoded with larger arrays.
  • One commenter wishes for amateur‑radio‑based, independently verifiable evidence for the Moon landings to counter conspiracy‑minded friends, with skepticism that such people would be convinced.