SSTV encodes an image as audio tones, scanning it slowly enough to fit through a voice-bandwidth channel. Received pictures build down the screen line by line, and noise shows up as streaks and tearing.
The International Space Station transmits SSTV images during special events, receivable on a handheld with a modest antenna. It is one of the most satisfying things a new operator can do.
At a Glance
- Category
- Digital data
- On the air since
- the late 1950s
- Bandwidth
- About 3 kHz, the same as a voice signal
- Speed
- Roughly 1–2 minutes per image
- What you need
- A sound card interface
- Where to listen
- 14.230 MHz is the best-known SSTV calling frequency