Re: LF: Re: EbNaut tests 137.490 kHz

[Markus Vester <markusvester@aol.com>]

Thank you very much Domenico!  Your feedback is especially valuable as I've been playing with a modified version of the SpecLab 1pps-PLL for audio generation which can switch the phase even faster.

BTW the transmit timing here is a rather inhomogeneus mixture:
- the LO of the homemade LF-Grabber TRX is derived from a permanently running FE5680A Rubidium at ~ 21.39475 MHz, which has indirectly been calibrated against Russian Loran,
- the 1490.0175 Hz audio frequency is controlled by GPS 1pps, 
- the symbol timing comes from the PC-clock controlled by ntp1.fau.de, which is based on a DCF77 receiver at the Erlangen University.
... I have to simplify that setup sometime in the future ;-)

Yes Gizmo and I are hoping to make it across to Joe (VO1NA) one of these nights. I think he is currently in the process of setting up frequency and samplerate calibrations. Here in Europe those steps may be easier, because we have a "critical density" of Ebnauteers who can play reasonably strong test signals between each other. On the other hand, I think that e.g. John (W1TAG), Jay (W1VD) and others have also been able to receive and transmit signals with absolute time and frequency calibration. 

All the best,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Domenico IZ7SLZ <iz7slz.domenico@gmail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 10 Dez 2016 11:27 am
Betreff: Re: LF: Re: EbNaut tests 137.490 kHz

Hello Markus and group,

here the results of your EbNaut transmissions obtained in JN80nu (qrb 1000 km)

UTC       En/N0     BER     Note

20.00      71.6       0%       1s/sym

21.00      71.6       0%       1s/sym
22.00      71.6       0%       2s/sym
23.00      71.6       0%       2s/sym
00.00      71.6       0%       2s/sym
01.00      71.6       0%       2s/sym
02.00      71.6       0%       2s/sym
03.00      71.6       0%       2s/sym
04.00      15.7       1.2%    2s/sym
05.00      71.6       0%       2s/sym
06.00       2.8       30%       2s/sym foff=-0.0002 Hz
07.00       6.7       21.2%    2s/sym foff=+0.0001 Hz

wav files recordered have been uploaded in the folder http://qsl.net/iz7slz/DF6NM. They can be used from anyone with the program EbNaut-rx.exe using nominal offsets (-10 Hz; 242.05 s).

Maybe your message has reached VO1NA.

73, Domenico iz7slz

On 10 December 2016 at 01:09, Domenico IZ7SLZ <iz7slz.domenico@gmail.com> wrote:

Hi Markus and LF,

i think that your previous email was not distributed.

Many thanks for the signal. FB copy here with a monster Eb/N0 without errors.

Decoded "DF6NM 73"

Time   Eb/N0

22.00   71.6 dB

23.00   71.6 dB

I will report the other transmission results  tomorrow and i will post the wav files in my small web-site.

73 and good weekend all !

Domenico, iz7slz

On 10 December 2016 at 00:23, Markus Vester <markusvester@aol.com> wrote:

Hi Domenico,

here are the EbNaut parameters. I've already sent those through blacksheep, but unfortunately I usually do not get my own mails back so I don't know whether the reflector has really distributed them.

Best 73 + GL,
Markus


-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 9 Dez 2016 11:10 pm
Betreff: Re: EbNaut tests 137.490 kHz

To obtain some extra sensitivity, I have now slowed down to 2 seconds per symbol, with transmissions starting 0.3 s after each full hour.

Frequency 137490 Hz,
8 characters, 8K19A,
2 second symbols (duration 21m52s)
Start times: 22:00, 23:00, etc. until 7:00 UT, plus 0.3 s transmit delay.

73, Markus

-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 9 Dez 2016 8:39 pm
Betreff: EbNaut tests 137.490 kHz

This evening I'll run some LF EbNaut tests again:

Frequency 137490 Hz,
8 characters, 8K19A,
1 second symbols (duration 656 seconds)
start times: 19:30, 20:00, etc, plus 0.3 s transmit delay

Best 73,
Markus (DF6NM)