Also known as: Contestia
Contestia is an amateur HF text mode created as a lighter, faster relative of Olivia. It keeps Olivia’s core idea — characters sent as one of several tones (M-ary FSK) protected by a forward-error-correction block — but shrinks the character set and thins the coding so it moves text about twice as fast while still copying well under noise.1 The result sits between raw RTTY speed and Olivia-grade robustness.
Overview
Like Olivia, Contestia is named by a tones/bandwidth pair — for example 4/250, 8/250, 8/500, or 16/500. It uses the same MFSK signalling and a Walsh/Hadamard block code, but encodes only a 6-bit character set (upper-case letters, digits, and common punctuation) instead of full 7-bit ASCII, and applies a shorter code. Fewer bits per character and less coding overhead mean each character occupies fewer MFSK symbols, so text scrolls roughly twice as fast as the equivalent Olivia mode. The receiver still correlates incoming tones against the codeword set, preserving good weak-signal behaviour.
Technical characteristics
| Property | Value |
|---|---|
| Modulation | MFSK, 2–64 tones |
| FEC | Walsh/Hadamard block code (lighter than Olivia) |
| Character set | Reduced 6-bit (no lower case) |
| Common variants | 4/250, 8/250, 8/500, 16/500 |
| Throughput | Roughly 2× the matching Olivia mode |
| Carrier | SSB audio, HF |
History
Contestia was defined in 2005 by Nick Fedoseev (UT2UZ), together with Con Wassilieff (ZL2AFP), specifically to keep much of Olivia’s noise immunity while being brisk enough for casual contacts and contest-style exchanges — hence the name.1 It is supported by the same sound-card software that handles Olivia, most notably Fldigi.
Deployment
Contestia is amateur-only, used for keyboard QSOs on HF where operators want more speed than Olivia gives but more reliability than RTTY. It shares the general HF digital sub-bands and has no formal calling frequency, so operators coordinate the exact tones/bandwidth by agreement or by decoding the ongoing signal.
Decoding it with GopherTrunk
GopherTrunk does not decode Contestia. As an HF amateur text mode it falls outside GopherTrunk’s trunking focus and is handled by Fldigi or MultiPSK. The primitives it relies on — MFSK tone detection and block FEC — exist in GopherTrunk’s DSP toolbox, but the Contestia framing itself is not implemented.