classical

The HB9CV antenna - Gain of this two element antenna is the same like gain of classical three element antenna of the YAGI type. Dimensions for 7-14-21-28 Mhz by pa3dlp

Olivia - The Olivia transmission system is constructed of two layers: the lower, modulation layer is an (almost) classical Multi-Frequency Shift Keying (MFSK) and the higher layer is a Forward Error-Correcting (FEC) code based on Walsh functions.