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Updated Audio Receivers (markdown)

Brumi-2021
2025-03-25 22:09:18 +01:00
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Audio-Receivers.md

@@ -16,7 +16,7 @@ Inside audio baseband spectrum , there is a sub-carrier audio tone , modulated i
Hackrf has poor sensitivity to receive directly those HF Wefax signals, (mainly broadcasted in HF band : 3 Mhz to 16 Mhz)
Normally we should better add a front up-converter with better HF pre-amplifiers and a reasonable small HF antenna.
WEFAX's format is a derivative of the [Automatic Picture Transmission (APT)](https://www.sigidwiki.com/wiki/Automatic_Picture_Transmission_(APT)) originally developed for transmission from the polar satellites of the USA.
WEFAX has 60, 90, 100, 120, 180 and 240 LPM (Lines per minute) speeds, and two IOC (Index of Cooperation) modes, IOC 576 and IOC 288. Most weather forecasts are sent in IOC 576. Our initial target would be , WEFAX-IOC576 standard. https://www.sigidwiki.com/wiki/WEFAX.
WEFAX has 60, 90, 100, 120, 180 and 240 LPM (Lines per minute) speeds, and two IOC (Index of Cooperation) modes, IOC 576 and IOC 288. Most weather forecasts are sent in IOC 576 , 120 LPM . Our initial target is WEFAX-IOC576 standard. https://www.sigidwiki.com/wiki/WEFAX.
Here you can see the actual Worldwide Weather fax HF Stations with his frequencies , and exact GMT map transmission time .
https://weatherfax.com/stations/