I've had regular success picking up the SSTV transmissions from the ISS, using my VX-6 HT and just holding the speaker up to the mic of my smartphone with the SSTV decode software on. I've always received a strong signal. However despite many attempts with various satellites, I'm unable to pick up any beacons. Can anyone explain? Is it just that the ISS is in lower orbit than all the sats, so the signal is stronger, or does the ISS transmit at higher power than any sat?