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Technical Topics => Equipment => Topic started by: The Insomniac on September 27, 2014, 2215 UTC

Title: Good Antenna for Raspberry Pi
Post by: The Insomniac on September 27, 2014, 2215 UTC
I got a Pi a while back and I've played around with it a bit. I downloaded a program that I can run on it that let's it broadcast on FM and HF spectrum through one of the pins on its board. What would be a good antenna for me to attach to it to broadcast shortwave?
Title: Re: Good Antenna for Raspberry Pi
Post by: audiokaos on September 29, 2014, 1402 UTC
After a LPF, the proper antenna for the band that you'd be using it for... The Raspberry Pi's GPIO is *very* noisy & harmonic. A LPF is very much needed.
Title: Re: Good Antenna for Raspberry Pi
Post by: The Insomniac on September 29, 2014, 2239 UTC
Got it. So essentially, after I get the LPF, I'll just need an antenna tuned for the shortwave band I choose. Any broadcasters recommend a frequency or band, or is 6925 kHz good? Other than that, Woo hoo! I can combine my two favorite hobbies!
Title: Re: Good Antenna for Raspberry Pi
Post by: audiokaos on October 01, 2014, 1615 UTC
Got it. So essentially, after I get the LPF, I'll just need an antenna tuned for the shortwave band I choose. Any broadcasters recommend a frequency or band, or is 6925 kHz good? Other than that, Woo hoo! I can combine my two favorite hobbies!

Pretty much - However afaik Raspberry Pi only uses the FM mode so apart from digital & actual FM I'm not sure what you might use it for. AM/SSB I believe is not possible with it - at least yet..<g> Check this out for some info on setting up LPF's and antennas-

https://github.com/threeme3/WsprryPi
Title: Re: Good Antenna for Raspberry Pi
Post by: The Insomniac on October 01, 2014, 2040 UTC
Got it. So essentially, after I get the LPF, I'll just need an antenna tuned for the shortwave band I choose. Any broadcasters recommend a frequency or band, or is 6925 kHz good? Other than that, Woo hoo! I can combine my two favorite hobbies!

Pretty much - However afaik Raspberry Pi only uses the FM mode so apart from digital & actual FM I'm not sure what you might use it for. AM/SSB I believe is not possible with it - at least yet..<g> Check this out for some info on setting up LPF's and antennas-

https://github.com/threeme3/WsprryPi

Is there any way to build a good shortwave antenna or would buying one have to be the way I would go?
Title: Re: Good Antenna for Raspberry Pi
Post by: audiokaos on October 01, 2014, 2201 UTC
It's dead easy to build one. Just check out the ARRL's website - Loads of plans for antennas for pretty much any situation. Dipoles are very easy to construct - Just a T shape with the top bits cut to a specific length. Can be quite large though depending on the frequency. eg, for 6.925Mhz it is 33ft. 9 - 1/2in. or 10.299 M for one side...
Title: Re: Good Antenna for Raspberry Pi
Post by: The Insomniac on October 01, 2014, 2217 UTC
Thank you. I'm on the website. I hope I'll be able to start broadcasting eventually.
Title: Re: Good Antenna for Raspberry Pi
Post by: herman on October 15, 2014, 0122 UTC
Been using these for years without a tuner on 6935, with lots of qsl's. even one from across the pond. Par EF-40
http://www.universal-radio.com/catalog/hamwire/4965.html