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This Presentation

Is

For the Birds!

A guide to working the amateur radio FM satellites

SO-50 - AO-85 - AO-91 - AO-92

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An amateur radio satellite is an artificial satellite built and used by amateur radio operators for use in the Amateur-satellite service. These satellites use amateur radio frequency allocations to facilitate communication between amateur radio stations (Wikipedia)

It’s a (usually) crossband repeater in orbit!

OSCAR- Orbiting Satellite Carrying Amateur Radio.

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Modes

Used to be single letter designations:

  • Mode A - 2 m uplink / 10 m downlink
  • Mode B - 70 cm uplink / 2 m downlink
  • Mode J - 2 m uplink / 70 cm downlink

New uplink and downlink designations use sets of paired letters following the structure X/Y where X is the uplink band and Y is the downlink band.

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H

A

V

U

L

S

S2

C

X

K

R

15M

10M

2

M

70

cm

23

cm

13

cm

9

cm

5

cm

3

cm

1.2

cm

6

mm

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How do you know when and where to look?

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Orbital Tracking

Orbitron, Satscape, HRD, AMSAT, N2YO.com -- Use these before going outside to know when

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SkyView Satellite Guide (iOS), ISS Detector (iOS/Android), Satellite AR (Android) -- Use these when outside to know where to point in the sky

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Orbital Tracking

  • Called Keplerian Elements, “Keps”, two-line elements, or TLEs

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Make sure to let the software automatically update TLEs or do it manually at least once a month

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Programming Your Radio

Frequencies can be found in your tracking software, N2YO.com, AMSAT, etc.

Don’t forget Doppler shift! Adjust the 70cm side. If it’s the uplink (TX), start below the center frequency and adjust up during the pass. If it’s the downlink (RX), do the reverse.

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(AO-91 and AO-92 have Automatic Frequency Control and do not require Doppler shift)

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What to Take Outside

  • HT (Kind of important!)
  • Hand mic
  • Headphones
  • Antenna (Arrow II Satellite Antenna or Elk Log Periodic Antenna)
  • Tablet or phone to know where to find it in the sky
  • Clock
  • Compass

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Finding the Satellite Outside

Azimuth -- Numerical value of compass heading (0 to 360). North is 0/360, East is 90, South is 180, West is 270

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Elevation -- Elevation above horizon

Horizon is at 0 degrees. Directly

overhead is 90 degrees.

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Transmitting!

  • Use the minimum power needed to make the contact
  • Do NOT transmit if you can’t hear the bird
  • Make your contact quickly. Other people are waiting
  • Callsign and grid square (N4BWR, EM73)
  • Don’t forget to use your pre-programmed Doppler shifts

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Congratulations!

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Other Satellite Opportunities

  • NOAA Weather Satellites (WXtoIMG software)
  • Digital Birds (PSK31, Packet, SSTV, Digital Voice)
  • ISS Digipeater
  • ISS SSTV (sometimes)
  • Talk to An Astronaut (Good luck!)
  • NASA May Ask For Your Help! -- Smartphone sats, telemetry, testing (Juno, for example)
  • RX telemetry from research & educational satellites
  • WalMart Parking Lots On The AIR (WMPLOTA)