Ham Radio Satellites — How Technicians Can Use Them

What Amateur Satellites Do

Amateur satellites serve as repeaters in orbit — receiving signals from ground stations and retransmitting them back down. Because they orbit at 400–800 km altitude, their footprint covers hundreds of miles simultaneously. A contact through a satellite in low earth orbit can connect two stations 1,000–2,000 miles apart during a single pass overhead — something impossible for a Technician's handheld to do directly.

Active Amateur Satellites for Beginners

International Space Station (ISS / ARISS): The ISS carries an amateur radio station operating on 145.825 MHz (APRS packet) and occasionally activates voice repeater capability. Receiving ISS APRS packets requires only a 2-meter radio tuned to 145.825 MHz. Voice contacts through the ISS repeater have been made with basic HTs during favorable passes.

AO-91 and AO-92: Fox-1 series amateur satellites with FM voice transponders. Uplink (your transmit) on 70cm; downlink (your receive) on 2 meters. A dual-band HT works for both. Check amsat.org for current operational status — satellite status changes as batteries and components age.

SO-50: A long-running FM satellite with a 2m uplink and 70cm downlink. One of the most consistently active FM voice satellites. Requires a 74.4 Hz CTCSS tone on uplink.

Equipment Needed

Minimal setup for FM voice satellites: a dual-band HT (2m/70cm) and a handheld Arrow Antenna or similar cross-Yagi. The directional antenna is important — it focuses your signal toward the satellite and rejects ground noise on the receive side. Total equipment cost: $30–$80 for a used Arrow Antenna, plus whatever you paid for the HT.

Tracking the Satellites

Satellites move across the sky in 5–15 minute passes. Free apps: ISS Detector (Android/iOS) shows real-time position and upcoming pass predictions. Heavens-Above.com provides printable pass schedules for any location. Gpredict (desktop) offers more detailed tracking. Set up pass alerts for AO-91, AO-92, and SO-50 at your location to know when to be ready.

• How do I know if the satellite is working today?
  Check amsat.org — AMSAT (the Radio Amateur Satellite Corporation) maintains current status for all amateur satellites. Satellites can go inactive due to battery degradation or equipment failures. AO-91, AO-92, and SO-50 have been the most consistently available FM voice satellites in recent years, but always verify before a planned pass.
• Why do I need a directional antenna — can't I just use my rubber duck?
  Some hams successfully use rubber duck antennas during high-elevation passes (when the satellite is near overhead). But in most passes, the satellite is at low elevation where your 5-watt signal needs all the antenna gain it can get to reliably reach the satellite. The Arrow Antenna provides about 9–10 dBi gain — effectively multiplying your transmit power several times over. It also helps reject noise on receive. Start with a directional antenna for the best chance of success on your first satellite contact.