Another option to consider if using a computer ( i.e. Raspberry Pi or other ) connected to the internet is to simply set up ntp or chrony for time keeping on that computer. NTP should keep your computer clock to within a few 10's of milliseconds - well within the needs of WSJT-X synchronous modes. One less external device ( GPS module ) - keep it simple.
cheers, Graham ve3gtc On Tue, May 21, 2024 at 12:14 AM Roger Rehr via wsjt-devel < wsjt-devel@lists.sourceforge.net> wrote: > Hi Ev, > > If I were doing this with audio as you indicated you want to do, I would > use a Raspberry Pi with a USB GPS Dongle to play the audio files with > GPS-aligned timing, rather than avoiding the WSJT modes. The RPi has a 3.5 > mm jack for audio out at line level, and you could feed that into your > transmitter audio input. > > A 4 GB Raspberry Pi (which is what I used) is $55 at adafruit > https://www.adafruit.com/product/4295 > and the GPS USB dongle is ~$17 at Amazon > > https://www.amazon.com/Navigation-External-Receiver-Raspberry-Geekstory/dp/B078Y52FGQ/ > > I wrote a simple beacon script using python that cycles through 3 > different audio files, each starting at the top of the minute. The > starting times are plenty precise, consistently less than 10 milliseconds > off the minute. > > You could use one wav file for Q65-60C, one for CW, one for SSB as you > suggest, or you could make it as complicated as you want, starting files > not only at the 0th second of the minute but also at the 15, 30, and 45 > second marks for the shorter modes, and you could mix modes within any > given minute and timing would be preserved. > > The simple python script for a beacon cycling among 3 modes, each starting > at the top of the minute is at the URL > https://w3sz.com/BeaconPlayAudio3.py > The python script starts automatically when the RPi boots and the unit > operates as a black box with no need for user intervention or internet > access. > > In this test I used for the 3 modes Q65-60C, Q65-15C, and Q65-15A only > because I had audio files for those modes in front of me so no work was > required. > > After I click "Send" on this email I will start making a simple document > with the "prescription" describing the details on setting this up as well > as an illustration of the results. The document should be at > https://w3sz.com/AudioBeaconDescription.pdf by daylight tomorrow (Tuesday > 5/21 EDT). > > It might seem tedious in the telling but it would take less than an hour > to set this up from the time the RPi box arrived in the mail. If you are > interested in doing this but not comfortable with the details, I would be > happy to get the RPi set up and running so that all you had to do was > connect the power, plug in the GPS dongle, and connect the audio cable from > the RPi to the transmitter audio in. > > 73, > > Roger Rehr > > W3SZ > > > > > On 5/18/2024 02:37 PM, Ev Tupis via wsjt-devel wrote: > > Hello all, > Later this fall, I hope to install a constellation of multi-mode VHF+ > beacons. CW, SSB, and MD (machine decodable) all in the same transmission. > > My intention is to record the audio digitally (MP3) and drive a multimode > radio in "SSB" mode, playing it over-and-over. > > Is there a WSx mode that does not require the TXing and RXing stations to > be timeslot locked? > > I can always fall "back" to PSK31/63 or RTTY, but would like to explore > the WSx approach a bit before I do. > > If this is off-topic, I would be happy to receive off-list input, of > course. > > Thank you for the work that you do. > > Sincerely, > Ev, W2EV > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel >
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