Good day LF, all some coherent bpsk test transmissions with EbNaut are now scheduled from here (JN80NU) on QRG = 136170.00 Hz every hour starting at 13:00. Message is composed of 16 characters with 1
My rx is back on from 19th 15:06 UT, recording 135kHz to 138kHz. I couldn't decode the 15:00 message, losing the first 6 minutes was too much. It is quite possible to decode with a third of the messa
Hi Paul, thanks for trying to read my signal. Yes, carrier is ON 2 minutes before and switched OFF about 2 minutes after the EbNaut sequence. I will increase now transmits intervals to 30 mins. All t
Nothing here either - I've been recording each 17.4 minute session using sampling rates of 31.25 or 62.5Hz, but the decoder throws up either nothing or a garbage decode with 30% bit errors indicated
Hi Domenico, got your 15, 16 and 17 UT transmissions ok, with Eb/N0 3.1, 11.8 and 9.0 dB respectively. It looks like the symbol timing is a bit over one second late. Best 73, Markus (DF6NM) --Ursprün
got your 15, 16 and 17 UT transmissions ok, with Eb/N0 3.1, 11.8 and 9.0 dB respectively. It looks like the symbol timing is a bit over one second late. Best 73, Markus (DF6NM) --Ursprünglich
. I just tried 17:17:20,+2m in 8.33 mHz and got a nice sharp line on frequency. S/N 17.3 dB in 120 seconds, signal calculator says you should be Eb/N0 = 7.08 dB with that. But no decode of the 17:00
got your 15, 16 and 17 UT transmissions ok, with Eb/N0 3.1, 11.8 and 9.0 dB respectively. It looks like the symbol timing is a bit over one second late. Best 73, Markus (DF6NM) --Ursprünglich
As far as I can see the transmission is on the nominal frequency. I needed the offset because I had set my center frequency to 136171 Hz, minus 0.0175 Hz due to known RX DDS rounding. The sequences s
-- In the past, Domenico sometimes suffered from a GPS ambuiguity which gave him a one second clock error. -- Yes, my clock is derived from Jupiter GPS and its 1_pps signal. Sometimes nmea is late o
Finally a decode! From the 18:00 message found rank 0: JS PARIS. IZ7SLZ ps [ 10 90 90 90 90] re-encode 340/1040 ber 3.27e-01 Es/N0=-9.9 Eb/N0=0.4 effrate=1/10.83 This with zero time and frequency off
I'm looking at the 30 minute carrier and there's obviously a problem http://abelian.org/vlf/tmp/151119c.gif The main peak is off frequency and it's jumping around a lot. Could be a problem with my ti
Definitely a timing problem at my end. http://abelian.org/vlf/tmp/151119d.gif shows the time offset reported by my timing program (vttime from vlfrx-tools), during Domenico's 18:00 message. It's havi
BINGO !!!!!!!!! (Text = "GE PAUL TNX RPRT" in case the graphic below doesn't get thought near Instant decode on the 1930 Transmission Inline images 1 (ignore the Rx frequency showing as 60000, it
Paul, interesting spectrum... but before ripping the RX apart I would't rule out propagational Doppler. The main component is half a mHz low which seems reasonable after dusk. The companions are a co
Very nice, congratulations! Markus --Ursprüngliche Mitteilung-- Von: Andy Talbot <[email protected]> An: rsgb_lf_group <[email protected]> Verschickt: Do, 19 Nov 2015 8:55 pm Betreff: R
I see what you mean, the carrier looks quite ragged on there too. I guess I'm used to the nice sharp lines we get a VLF. These super high frequencies are a bit different! But I certainly have a probl
Yes, same here when using the show_rawsyms3a utility. The peak in the skyblue spectrum-of-squares will conveniently guide you to the correct frequency and time offset if Eb/N0 is above 4 dB or so. T
Thank you Andy for the report and many compliments for your receiver. Just for another test, transmission in progress (21:30 UT) is formed by 39 characters at 0.5s. Total duration is 17'52". Let's se
