Dan, Lou, Ron, and others, Dan you are doing a great job of beating the drum: searching for "solutions for transmitting on HF" The question is a big one and can be broken down into three basic issues. The basic or elemental SDR platform solutions are changing rapidly. With the third generation SDRs, and tightly integrated RFICs, there are a number of excellent, high performance, solutions, as has been pointed out, and as you well know.
I think your real question, Dan, asks about the rest of the HF system: the elements necessary to complete the transmitter for practical communication purposes. The question moves beyond SDR hardware to that of station building. That station building part of the system, I call the "interface". The "interface" provides the receive and transmit filtering and antenna switching, power control, amplifier stages, and other functions. The "interface" is built upon analog technology. Much information along these lines is addressed by the QRP (low power) movement within Amateur Radio. The American Radio Relay League (ARRL) publishes small paperback books devoted to QRP equipment and station building, and available for purchase on-line. The material covers homemade solutions, as well as purchased kits and turnkey solutions. Maybe, a group of interested GRC/SDR enthusiasts can collect and publish a few example systems as starters for those who want to experiment in this area. The second aspect of the "solutions" question asks if there are suitable GRC DSPs as starters, at least. With Lou's help, I have authored a library of transceiver DSPs for all of the commonly used HF transmission modes. The GRC DSPs are 'ham friendly' in the sense that they implement functional, ordinary and familiar transceiver interfaces. However, I have no easy means to publish the DSP's. Would collecting and publishing GRC DSPs be helpful at addressing your "solutions" question? If so, what is the best approach for maximum visibility to the experimenter community? Last but not least, a third issue for communication system functionality, is to use the GRC GUI to control the auxiliary functions of an HF transmitter, e.g. transmit / receiver relay. I do not know of a means to access the GPIO from the GRC GUI. My present solution is to use current from the USRP transmit or receive LED signal to control external equipment via a relay system. Maybe someone can publish a different solution. Looking forward to further discussion on the HF transmit solution question. Regards, John Petrich -----Original Message----- From: Ron Economos [mailto:w...@comcast.net] Sent: Wednesday, April 6, 2016 7:23 AM To: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] HF transmitter hardware solutions There's a transverter for the bladeRF. https://www.nuand.com/blog/product/hf-vhf-transverter/ hackRF specification has been changed to 1 MHz to 6 GHz. https://greatscottgadgets.com/hackrf/ Ron On 04/06/2016 07:02 AM, Daniel Pocock wrote: > > What solutions are people using for transmitting on HF bands (1 - 30 MHz)? > > There is a lot of information online about upconverters for receiving > the HF bands. > > However, like receivers, many of the SDR transmitters only seem to > cover bands above 30MHz[1] e.g. > > HackRF: 30MHz - ... > bladeRF : 300MHz - ... > USRP B2x0: 50MHz - ... > > Is anybody using a downconverter or is there some other SDR model that > natively supports the HF spectrum and is accessible to hobbyists? > > Some other things come to mind: > - power amps for HF bands > - RF switches for using a single antenna in half-duplex mode, > alternating between receive and transmit > > > > 1. > http://www.taylorkillian.com/2013/08/sdr-showdown-hackrf-vs-bladerf-vs > -usrp.html > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
