Contestia
A faster relative of Olivia that trades some robustness for speed.
What does it sound like?
Like Olivia: many tones hopping, a little quicker.
12-second example. A clean example made with the free fldigi program (Contestia 8/125); signals on the air usually sound noisier.
Who uses it?
Amateur radio operators.
Where and when can I hear it?
Various ham frequencies.
The science
Contestia is built directly on Olivia's design: one tone at a time from a set (4 to 32 tones in fldigi standard formats), spread across 250 to 1000 Hz, with Walsh-function error correction. It gets roughly twice Olivia's speed in two ways: it uses a smaller error-correction block (32 symbols instead of 64) and a 6-bit character set instead of 7-bit ASCII. The standard formats run from about 30 to over 100 words per minute depending on tones and bandwidth.
Why use it?
Contestia is a middle ground: it still copies below the noise, about -5 to -13 dB signal-to-noise depending on format, while moving text much faster than Olivia. The trade-off is a reduced character set that prints in one case only, and roughly 1.5 to 3 dB less sensitivity than Olivia.
Lore
Contestia was developed by Nick Fedoseev, UT2UZ, in 2005. Its reduced character set prints only in one case, like old RTTY, and fldigi notes that some traffic nets may not want it for that reason.
Easily confused with
- Olivia: Olivia is slower and more robust