Re: LF: EbNaut April 1 / 2

[Markus Vester <markusvester@aol.com>]

Hi Stefan,

normally 1pps harmonics are not such a big problem at LF as on VLF because the harmonic number is much larger. Also the 1pps would have to ingress into the receiver, rather than leakage from the other soundcard channel.

Having said that, however your opds instance may be the one exception to the rule ;-) There's a 1 Hz fence around 137500 Hz, but this is apparently caused by second-order intermodulation (MSF and DCF77, 60 + 77.5 kHz) in the broadband antenna buffer.

Here in Europe I would only try to avoid Loran lines from Slonim (6.25000 Hz harmonics from GRI 8000, providing useful calibration marks) and maybe Anthorn (7.428316745 Hz from GRI 6731). Unfortunately this is no longer a "problem" in America.

Best 73,
Markus


-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 2. Apr 2018 21:33
Betreff: Re: LF: EbNaut April 1 / 2

Hi Markus,

Even on LF i would avoid integer Hz frequencies.

73, GL, Stefan

Am 02.04.2018 21:22, schrieb Markus Vester:

Thanks for info John, good to know. So let's do one more night, same schedule as last night, 22 to 4 UT on 137520 Hz - assuming that frequency is clear for you?

Best 73,
Markus (DF6NM)

-----Ursprüngliche Mitteilung-----
Von: John Andrews <w1tag@charter.net>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 2. Apr 2018 21:10
Betreff: Re: LF: EbNaut April 1 / 2

Markus,

Just to let you know that others are looking as well. I've easily been
able to decode the K3RWR transmissions, but have had no luck with the EU
signals thus far. Still working through the possibilities, though! And
being 100 km closer to you than W1VD, I have no excuse.

John, W1TAG

On 4/2/2018 2:39 PM, Markus Vester wrote:
> Many thanks again to Jay, I'm really amazed that you were able to
> capture every possible transmission from here between midnight and 4 UT.
>
> BTW I don't think that Ric's ERP is any weaker than mine. Maybe the
> extra distance across the mountains does make a difference - we've got
> to flatten the Alps ;-)
>
> Domenico's auto-decoder works like a charm - it didn't miss a single
> transmission from Ric or myself, including a couple of daylight tests.
>
> Joe DF2JP was also sending his message every hour, albeit with slightly
> changed format (5ch 3s 8K19A, but CRC 16 instead of 20). As far as I
> could see, his frequency wandered gradually from 137523.963 Hz at 0 UT
> to 137524.009 Hz at 6 UT. He left the unmodulated carrier on during each
> other half hour, so you may be able to find his trace in a spectrogram,
> or perhaps a peak in the red "show_rawsyms" spectrum. Joe mentioned that
> he will be able to fix GPS-lock soon.
>
> Also had another look on Rob's frequency but again nothing found.
>
> Jay I wonder if you are also preparing to send EbNaut yourself? For the
> time being, our current ad-hoc arrangement would probably work both
> ways: Europeans start transmitting on the full hour within a few Hz of
> 137522, and Americans send near 137490 during second half-hours.
>
> Best 73,
> Markus
>
>
>
> -----Ursprüngliche Mitteilung-----
> Von: jrusgrove <jrusgrove@comcast.net>
> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
> Verschickt: Mo, 2. Apr 2018 13:31
> Betreff: Re: LF: EbNaut April 1 / 2
>
> Markus, Riccardo & EbNaut enthusiasts
> DF6NM 5 decodes, sadly no decode of IW4DXW ;~( . Riccardo, any chance
> for more transmitter power?
> DF6NM:
> 0000 Rank 0 EbN0 6.4 decoded
> 0100 Rank 0 EbN0 7.8 decoded
> 0200 Rank 0 EbN0 5.3 decoded
> 0300 Rank 0 EbN0 9.3 decoded
> 0400 Rank 2561 EbN0 -1.7 decoded
> Decoder attachments below.
> Jay W1VD
>
> Re: LF: EbNaut April 1 / 2
> Von: Domenico IZ7SLZ <iz7slz.domenico@gmail.com>
> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
> Datum: Mo, 2. Apr 2018 11:35
> Hello Markus, LF,
>
> Transmissions from you and from Riccardo have been decoded here.
>
> Congratulations for the good going.
> http://www.qsl.net/iz7slz/
>
> I'm still trying to extract the 21.00UT message from DF2JP but NIL till now.
>
> BTW his carrier was strong here in JN80 so it is only matter to guess
> the right frequency and time offsets.
>
> Compliments also to Joe for his EbNaut tests. If necessary, i can change
> settings of my auto-decoder if Joe wants make further transmissions.
>
> It is a bank holiday today here and the neighbor garage - jamming my LF
> reception during the day - is closed. So very low noise now: good for
> testing EbNaut with ground waves.
>
> All the best
>
> Domenico, iz7slz
>