Raspberry Pi as WSPR transmitter up to 250 MHz

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Guido PE1NNZ has released code that he says enables the Raspberry Pi to operate as a WSPR transmitter at HF and VHF.

Guido has modified the WsprryPi code originally developed by Dan Ankers MD1CLV. He says the Raspberry Pi requires just a Low Pass Filter (LPF) and antenna connected to the GPIO4 pin in order to function as a WSPR transmitter.

The PE1NNZ code and binary - https://github.com/threeme3/WsprryPi

Dan Ankers MD1CLV WSPR - http://m0xpd.blogspot.co.uk/2013/01/raspberry-whispers.html

WSPR on the Raspberry Pi - http://www.southgatearc.org/news/march2013/wspr_on_the_raspberry_pi.htm

2000km DX using the Raspberry Pi

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Eddie G3ZJO used the 10 mW of RF that can be generated from the Raspberry Pi computer board to get over 2000 km on the 7 MHz band.

The Raspberry Pi board can operate as a WSPR transmitter covering LF, HF and VHF up to 250 MHz.

Eddie G3ZJO connected the board's GPIO port via a low pass filter to a 40m Doublet for the 7 and 14 MHz bands or to a small Marconi inverted L just 6m up 6m out for the 472 kHz band which he estimates generates an ERP of 0.5 microwatts.

Among the stations who received his WSPR signal were:  

  • LA9JO JP99gb 2124km on 7MHz
  • LY2BOS KO24or 1736km on 14MHz
  • IK1WVQ JN44cb 1133km on 7MHz
  • G4KPX  JO02dj 80km on 472kHz
  • G3XIZ IO92ub 46km on 472kHz

The PE1NNZ code and binary to turn the Raspberry Pi into a WSPR LF/MF/HF/VHF transmitter is available at https://github.com/threeme3/WsprryPi

Thailand plans for digital radio

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Thailand's National Broadcasting and Telecommunications Commission has indicated that it will likely use Australia's digital radio system as a model to migrate from analog, according to the Bangkok Post.

The chairman of the NBTC's broadcasting committee, Col Natee Sukonrat, said the regulator is studying the digital radio transition in Australia, which according to the article is the country that is viewed as the most successful in implementing the scheme. Nevertheless, the NBTC has not chosen its digital radio standard. Options include DAB+ (which is used in Australia), DRM, or iBiquity's HD Radio system.

Natee said the launch of digital radio in Thailand would provide choices to consumers as it would be available in parallel with the existing analog system. There will be no shutdown of the analog system. He also indicated that NBTC expects to allot unused VHF spectrum for digital radio and will begin licensing next year, likely first in the major provinces

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