Hi Stefan, Domenico, to get an idea of the tolerances, you can convert the spectrum from http://df6nm.bplaced.net/VLF/fec_tests/ebnaut_data_09200300.zip into a wav and play around with the time offse
Found myself ordering a Trimble 10MHz GPSDO the other day. I have a Thunderbolt but don't want to dedicate it to a receiver because it's handy in the lab. You might consider the packet format used by
You might consider the packet format used by vlfrx-tools, which (correct me if I'm wrong Wolf) can also be read by Spectrum Lab. It has the fields you need and a magic number to sync on. Rummaging t
Continuing on this theme... Having abandonned my idea of a direct conversion Rx due to uncontrollable DC offsets, and not yet finished a locked clock for my SDR-IQ, I wondered about the next stage. T
Andy This feature is built into Spectrum Lab ... I run 1 kHz (divided down GPS) into the sound card's right channel. Works as expected. Jay W1VD WD2XNS WE2XGR/2 -- Original Message -- From: andy.g4jn
Spent some time today cobbling together a receiver for 137 kHz. System noise measures about 4nV/m equivalent field strength in 1Hz with a BF245B front end but I've not yet attached it to an antenna -
Hi Paul, Markus and all, in this weekend i have made a simple modification at my LF TX to improve frequency stability. I have phase-locked the 10 MHz OCXO of the exciter with the 10 kHz signal coming
Hi Domenico, Paul, LF, Great work indeed! 73, Markus (DF6NM) --Ursprüngliche Mitteilung-- Von: IZ7SLZ <[email protected]> An: rsgb_lf_group <[email protected]> Verschickt: So, 18 O
The signal is much too strong to be a good test, you should still decode quite easily at DF6NM if you drop to 5W. I got the system noise down to 1.5nV/m per root Hz which is far lower than it needs t
I have an E-field rx running on the 137 kHz band, GPS locked. Here is the 'first light' spectrogram http://abelian.org/tmp/lf151023a.png which covers 137 kHz to 138.5 kHz. It's a bit shaky, everythin
From about 18:08:20 to 18:41 there was an immensely strong signal on 137508.82 Hz which looks like carrier but was very rough. Spectrum in 5mHz bins http://abelian.org/tmp/lf151023b.gif Looks like I
Hi Paul, looks like you picked up G3XDV in Opera-32 mode. Sidebands are from the 8.192 s AM modulation. Opds spot from here: 2015-10-23 18:41:35 G3XDV 843km 137508.822Hz 4mHz -29.8dBOp 72% 21.0dB IZ7
Good evening Paul, Markus and all, thank you for your updates. I will start some EbNaut transmission at 22.00 each hour and hope that Paul can make some measurement on my signal . Qrg is 137502.24 Hz
Thanks for the info. If that's an Opera signal then maybe my timing system isn't working so bad after all. I see. Hmm, a lot of energy in the carrier! Hopefully there will be some snippets of pure ca
Hi Domenico, Paul, good decode again from the first transmission which started accurately at 20:00 UT. I only noticed that I had to reduce the frequency offset by half a milliHz compared to earlier t
Hi all, Markus, thank you for the report. The small difference in QRG is due probably to the fact that i'm not using resample now. Transmission of 6 char./3s with 10 W will start in few seconds. GL D
Domenico, nil from the 10 Watt transmission at 21:00 UT, only noise. Could you perhaps leave the carrier on during the pause, to let me check signal level and frequency? 73, Markus --Ursprüngliche Mi
Domenico, the QRP carrier is not visible here. The attached spectrum shows a stored peak from a short 100 W carrier around 20:40 (green). The yellow trace is the latest spectrum from approx. 21:30 to
No Markus, i'm not sure now ! The power reduction that i'm now using is the built-in circuit of the PA (ex-marine reserve transmitter): one relais takes the output of the driver stage and brings it d
