Amateur Radio

Amateur satellite guide

How to work amateur radio satellites. Equipment, tracking, and procedures for your first satellite QSO.

Amateur satellite guide

How to work amateur radio satellites — from first FM contact to linear transponders.

What you need

Working amateur satellites is easier and cheaper than most operators think. For FM satellites, you can make contacts with an HT and a handheld antenna. For linear transponder satellites, you need a dual-band all-mode radio.

FM satellites (easiest)

FM satellites work like repeaters in space. Transmit on the uplink frequency, receive on the downlink. The satellite retransmits your signal.

Minimum equipment:

  • A dual-band HT (Yaesu FT-65R, Icom IC-T70A, etc.) with 5W
  • A handheld dual-band Yagi (Arrow 146/437 or Elk 2M/440)
  • A satellite tracking app (ISS Detector, Heavens-Above, or SatPC32)

Procedure:

  1. Check the satellite pass schedule using a tracking app
  2. Program the uplink and downlink frequencies into your HT
  3. When the satellite rises above the horizon, point the antenna at it and call
  4. Track the satellite across the sky by hand, keeping the antenna pointed

Active FM satellites (check amsat.org for current status): SO-50, PO-101 (DIWATA-2B), ISS (when voice repeater is active).

Linear transponder satellites (more capability)

Linear transponder satellites receive a band of frequencies and retransmit them on another band. Multiple QSOs happen simultaneously. SSB and CW are used.

Equipment needed:

  • Dual-band all-mode radio (Icom IC-9700 or IC-905, Yaesu FT-847 or FT-736R, Kenwood TS-790A)
  • Azimuth-elevation rotator (Yaesu G-5500) for automated tracking
  • Cross-polarized Yagi antennas for 2m and 70cm
  • Satellite tracking software (SatPC32, PstRotator, Gpredict)

Doppler correction: Linear transponder satellites move fast enough that Doppler shift changes the received frequency during a pass. Tracking software can correct for this automatically with compatible radios.

The ISS

The International Space Station has amateur radio equipment and astronauts occasionally make contacts. ARISS (Amateur Radio on the International Space Station) coordinates scheduled contacts with schools and special events. The ISS packet digipeater and APRS system are also available.

ISS frequencies:

  • Voice downlink: 145.800 MHz
  • Voice uplink: 145.200 MHz (when active)
  • Packet/APRS: 145.825 MHz

Getting started

The lowest-cost entry into satellite operations is a dual-band HT and a handheld Arrow or Elk antenna. Total investment: under $200 for the antenna plus whatever HT you already own. Many operators make their first satellite contact within an hour of trying.