Downlink

437.550 MHz FM

Starting the decoder…

 

Pictures draw here, line by line.

Input level

Transmit plays a test picture through this speaker, for checking a second phone.

Receiving the ISS

  • Tune to 437.550 MHz FM. Current ISS events send Robot 36 there; older ones used 145.800 MHz and PD 120. Leave the mode on Auto and Downlink follows either.
  • Follow the drift. On 437 MHz the signal slides about 10 kHz during a pass: start near 437.560, pass through 437.550 at the middle, and finish near 437.540.
  • Open the squelch fully, so quiet parts of the picture are not cut off.
  • Moderate volume. The level bar should sit in the middle, never in the red.
  • Phone a few centimetres from the speaker, and keep both still while the picture draws.
  • A pass lasts about ten minutes. A Robot 36 picture takes 36 seconds, then the station pauses for two minutes, so a good pass gives three or four. If one is already under way, Downlink picks it up from the next line it hears.
  • Check pass times and the ARISS announcement before you head out: the frequency and mode can change between events. Once loaded, Downlink works with no signal.

Settings

Picture