Ham radio operators receive signals from Voyager 1 on Dwingeloo telescope

Original Article ↗ Hacker News Discussion ↗

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.