По следам темы HamShield для Arduino (VHF/UHF трансивер)

Previously we posted about the Raspberry Pi’s ability to modulate one of its pins to produce FM transmissions with PiFM. A developer (F5OEO) has recently expanded on this idea, and now the Raspberry Pi is capable of modulating and transmitting FM, AM, SSB, SSTV and FSQ signals anywhere between 130 kHz to 750 MHz.

To transmit with the Raspberry Pi all you need to do is plug in a wire antenna to Pin 12 (GPIO 18) on the GPIO port and run the PiTx software by piping in an audio file or image for SSTV.

Important Disclaimer: While the output power is very small, you should still take great care as the carrier is a square wave, and there is no filtering on the antenna output. So any transmissions will cause harmonics all across the spectrum – possibly interfering with life critical devices. A filter *must* be used if you actually plan on transmitting with any sort of range further than your room. The predecessor PiFM has been reported to have a range of 10cm without an antenna, so it may be best to not connect an antenna to the pin if just testing. With a simple wire antenna the range is increased to 100m which could affect your neighbours. There are also strict laws and licences governing transmitting in most countries so make sure you follow them carefully. In short, get your ham licence and understand what you are doing before transmitting with any sort of amplification/range.

The code for PiTX can be downloaded at https://github.com/F5OEO/rpitx. Also see the authors (@F5OEOEvariste) Twitter account at https://twitter.com/F5OEOEvariste for some more info about PiTX.

И далее - http://www.rtl-sdr.com/transmitting-fm-am-ssb-sstv-and-fsq-with-just-a-raspberry-pi/ '

Переводить лень :)

Нашел более подробное описание процесса: http://pe1nnz.nl.eu.org/2013/05/direct-ssb-generation-on-pll.html

In the RaspberryPi setup there is no DDS, but there is a digital-PLL on the micro-processor SoC which we can use for RF generation. By manipulating the Integer and Fractional dividers, a frequency can be generated from 0 to 250 MHz on GPIO4 pin with a resolution of about 20 Hz at 7 MHz. By alternating the Fractional divider between two nearby values, the resolution can be further increased to micro-Hz level; for this a 32 bit clock at 32 MHz is used to generate a PWM alike switching pattern between the two Fractional divider values.

> In short, get your ham licence and understand what you are doing before transmitting with any sort of amplification/range.

Позабавило, там видимо настолько мощный сигнал что без лицензии никак :)))
Интересно, при выводе напрямую с пина процессора, сколько там милливатт получается?

Jenny List G7CKF has made available an RF Breakout kit and a Pi-HF direct conversion radio kit for the Raspberry Pi

The breakout kit provides a breakout board to use the Raspberry Pi clock generator as an RF source or simple amateur radio transmitter. The Raspberry Pi has a built-in clock generator, a powerful frequency synthesiser which can generate frequencies up to 250MHz. This is enough to provide a useful RF signal source for experimentation, or given suitable filtering and antennas to allow the Pi to be used as a low-power amateur radio transmitter.

The Pi-HF is primarily for frequencies between 130 kHz and 30 MHz, however it has a bandwidth over 100 MHz and so will also perform at higher frequencies including the 50 MHz (6m) and 70 MHz (4m) amateur bands with reduced performance. It is not a software-defined radio, instead it is a traditional direct conversion radio receiver with software control.

Raspberry Pi RF Breakout Kit (video)
http://www.geeky-gadgets.com/raspberry-pi-rf-breakout-kit-video/

Language Spy - Amateur Radio and Raspberry Pi kits
http://shop.languagespy.com/products/rf-breakout-kit-for-the-raspberry-pi

Отсюда http://www.southgatearc.org/news/2015/november/raspberry_pi_ham_radio_kits.htm

DV4mini is a tiny but powerful USB stick that can change any PC into a HOTSPOT for the modes D-Star, DMR (C4FM Fusion) and now DPMR. It contains a powerful 32-bit micro controller as well as a complete 70cm transceiver and modulator/demodulator for GMSK and 4FSK (including raised cosine) as well as a USB interface. It does not require its own power supply as it is powered through the USB interface. Thanks to a power saving voltage transformer even older USB interfaces will suffice.Uses a comprehensive but simple to use software package which allows for the linking with DCS reflectors for both D-Star and DMR reflectors. But remember on DMR that this will not get you into the DMR Marc network, it will only get you into the DMR+ "Hytera" network for now.

http://www.g0hwc.com/dv4mini.html

Цитирование на Русскоязычном (!) форуме сообщений на иностранщецком языке не правильно. Это говорит о не уважении к другим участникам форума, кто не так уверенно владеет этим языком.

DV4mini is a tiny but powerful USB stick that can change any PC into a HOTSPOT for the modes D-Star, DMR (C4FM Fusion) and now DPMR. It contains a powerful 32-bit micro controller as well as a complete 70cm transceiver and modulator/demodulator for GMSK and 4FSK (including raised cosine) as well as a USB interface. It does not require its own power supply as it is powered through the USB interface. Thanks to a power saving voltage transformer even older USB interfaces will suffice.Uses a comprehensive but simple to use software package which allows for the linking with DCS reflectors for both D-Star and DMR reflectors. But remember on DMR that this will not get you into the DMR Marc network, it will only get you into the DMR+ "Hytera" network for now.



http://www.g0hwc.com/dv4mini.html


Широкополосный приёмник из DVB донгла - Страница 377

ReBeat
Ага, ту тему не читаю внимательно.

Если к шарпу прикрутят будет неплохо.
Похоже, пока нет. Зато для автономной работы к малинке прикрутили: http://www.skysmiths.com/tag/dv4mini/

Update
Прямая ссылка на реализацию http://klausw.bplaced.de/kwsoft/afu/tools/dv4mini_compact.php