By the way thats leads. A typo. It just hit me I had to cut the signal down so that the signal graph was in the middle. On the large antenna thats a 330K resistor to a 100K pot. For the wwvb simulator its simply the 100K pot turned up about 2/3rds of the way. The simulator is something like 60 uv out. Maybe you have a overdrive issue. Regards Paul.
On Tue, Nov 3, 2020 at 9:49 AM paul swed <paulsw...@gmail.com> wrote: > John > Yes I have used Chris's code to decode the wwvb AM timecode. I am in > Boston so just about as far away as you can get. Though maybe Florida is > further. But Boston is in more of a null from wwvb. > Granted the antenna is a tuned 10' X 10' 800 ft of wire loop and preamp > mentioned numerous times on time-nuts. It reliably during the day delivers > 100 uv at the end of the coax. > I found the teensy wwvb sdr really worked best during the day. With > respect to power for the antenna its just a power inserter I built, 8 Mh > choke, 100 ohm resistor, .47 uf coupling cap to the teensy. No magic at all. > One very serious issue with the teensy is that the audio module must be > directly stacked on to the cpu. I originally used 3" leeds those little > jumpers. It makes a mess of the clock signals. > Regards > Paul. > > On Mon, Nov 2, 2020 at 10:55 PM John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > >> Paul, >> >> Have you successfully decoded WWVB with Chris's code? >> >> I haven't gotten that to work. >> >> I'm using the same antenna set up I've used that works with the multipsk >> Clock program to decode WWVB that will decode fairly reliably as long as >> atmospheric conditions are favorable. >> >> Note, if using the Arduino IDE and you're connected to a PC; it will >> sometimes set the clock on the TFT to the PC's clock; I'm mentioning that >> since some that try this could think their set up is synced to WWVB when >> it >> actually grabbed time from the PC. Maybe the loader from Teensy does >> that; >> I haven't looked close enough yet to know for sure what's setting that. >> >> Glad you're making progress with your approach. >> >> 73's, >> John >> AJ6BC >> >> >> On Mon, Nov 2, 2020, 18:20 paul swed <paulsw...@gmail.com> wrote: >> >> > John thats exactly what Chris did. Its the teensywwvb.ino. It decodes >> the >> > AM timecode just as the DCF code does. In fact Chris's code is derived >> from >> > the DCF code with the changes you are asking about and it works. >> Download >> > his solution and read the comments throughout. The original DCF comments >> > are in it also. >> > >> > Its the starting point for the tinkering I am doing towards a BPSK SDR. >> > Thats a big leap for me. >> > What the code gives you is the frontend gain, followed by a bandpass >> > filter. Multiplier that mixes the LO and incoming signal to a lowpass >> > filter. Then on to AM detection and AGC. >> > >> > If you don't care to install the arduino IDE with teensy extension just >> use >> > notepad ++ to look at the code. Pretty exciting. >> > >> > Regards >> > Paul >> > WB8TSL >> > >> > On Mon, Nov 2, 2020 at 8:24 PM John C. Westmoreland, P.E. < >> > j...@westmorelandengineering.com> wrote: >> > >> > > Hello Time Nuts, >> > > >> > > I have a question - >> > > >> > > Has anyone been successful getting WWVB to decode using the example >> for >> > > DCF77 and making the changes for WWVB? >> > > >> > > Chris has his own approach - it's interesting - but on my setup at >> least >> > I >> > > haven't been successful with it - maybe it's my antenna - not sure >> just >> > > yet. >> > > Also - my screen eventually 'whites-out' after running that for a >> while - >> > > meaning - the screen goes completely white and I don't know what's >> doing >> > > that yet - I suppose it's a bug of some sort. >> > > >> > > But, with the DCF77 approach - it appears to identify bits OK - with >> the >> > > code having only minimal changes - so I'd like to go down that path. >> > > >> > > Note - I have a fork here - but it's debug - and not sure it's worth >> > > anything other than looking at some of the data that's being dumped. >> > > https://github.com/jwestmoreland/Teensy-DCF77 >> > > >> > > For DC7FF - the AM is just 0.2ms (1) and 0.1ms (0) with no AM at the >> > minute >> > > marker, but WWVB is a little more complicated - >> > > 0.2ms (0), 0.5ms (1), and 0.8 ms (Marker) - 2 consecutive markers mark >> > the >> > > end of current minute/beginning of next minute. >> > > >> > > The DCF77 code seems to take some advantage of the signal level/timing >> > and >> > > the dimensions of the TFT display for >> > > displaying the signaling - at least that's what it appears to me right >> > now >> > > unless I'm looking at this wrong - I guess that isn't >> > > a big deal until you try to deal with the marker timing for WWVB - of >> > > course I could be looking at this wrong right now too. >> > > >> > > Maybe trying something like the Goertzel algorithm like KE9NS has >> done in >> > > his work with WWV is worth taking a look at too with >> > > this setup. >> > > >> > > 73's, >> > > John >> > > AJ6BC >> > > >> > > >> > > >> > > >> > > >> > > On Sun, Nov 1, 2020 at 10:50 AM Mike Feher <mfe...@eozinc.com> wrote: >> > > >> > > > Too bad I am an old retired hardware engineer and know nothing about >> > > these >> > > > new SW controlled devices. Have Fun - Regards - Mike >> > > > >> > > > Mike B. Feher, N4FS >> > > > 89 Arnold Blvd. >> > > > Howell NJ 07731 >> > > > 848-245-9115 >> > > > >> > > > -----Original Message----- >> > > > From: time-nuts <time-nuts-boun...@lists.febo.com> On Behalf Of >> paul >> > > swed >> > > > Sent: Sunday, November 1, 2020 12:48 PM >> > > > To: Discussion of precise time and frequency measurement < >> > > > time-nuts@lists.febo.com> >> > > > Subject: Re: [time-nuts] WWVB teensy BPSK early experiments >> > > > >> > > > John sent the link on the teensy wwvb AM receiver. It can easily be >> > > > shifted to other frequencies. Using the work Frank dcf77 and then >> Chris >> > > > wwvb did with the PJRC audio design tool gives quite a bit of >> insight >> > to >> > > > the work that was done. >> > > > The system assumes a sample rate of 192Khz. That limits the receive >> > range >> > > > to about 98KHz. >> > > > I have not been able to confirm the rate I am using is 192Khz and >> when >> > > the >> > > > set command is used its not recognized. So somethings up. >> > > > The design Chris has essentially is a microphone input with some 38 >> db >> > of >> > > > gain feeding a bandpass filter around 60 KHz to a multiplier (RF >> mixer) >> > > > then a low pass filter. Chris and Franks design is much more than >> these >> > > few >> > > > words with spectrum display, signal level, and AGC. >> > > > So without any effort the frontend solution is sitting in the teensy >> > that >> > > > cuts out a bunch of typical wiring. Granted its not as tight as >> > discrete >> > > > components can be. But its a chunk of software code. No digi key >> orders >> > > for >> > > > L & Cs... :-) The output of the chain is 600 Hz audio that does >> contain >> > > the >> > > > phase changes. >> > > > >> > > > But the trick is creating the true I & Q channels. Not an issue to >> add >> > a >> > > > second multiplier and chain did that last night. But at someplace a >> 90 >> > > > degree phase change or delay needs to occur. >> > > > Or as suggested a hilbert transform. >> > > > Regards >> > > > Paul >> > > > WB8TSL >> > > > >> > > > >> > > > >> > > > >> > > > _______________________________________________ >> > > > time-nuts mailing list -- time-nuts@lists.febo.com >> > > > To unsubscribe, go to >> > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> > > > and follow the instructions there. >> > > > >> > > _______________________________________________ >> > > time-nuts mailing list -- time-nuts@lists.febo.com >> > > To unsubscribe, go to >> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> > > and follow the instructions there. >> > > >> > _______________________________________________ >> > time-nuts mailing list -- time-nuts@lists.febo.com >> > To unsubscribe, go to >> > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> > and follow the instructions there. >> > >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.