Re: ULF: EbNaut message transmitted from ground loop

[Markus Vester <markusvester@aol.com>]

Hi Stefan,

perfect decodes at DL0AO:
H-field (E-W): Eb/N0 = 5.0 dB(car), 5.4 dB(sym),
E-Field: Eb/N0 = 11.0 dB(car), 10.9 dB (sym).

Thanks for the nice nighttime activity!

Best 73,
Markus


-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 6. Apr. 2019 22:42
Betreff: ULF: EbNaut message transmitted from ground loop

Hello Markus, ULF,

I'm now sitting in my car, TXing in the forest. It is very silent here. I can hear a faint 'crk' in the FETs when the phase toggles :-)
Getting 2.44 A now on the 1130mground loop, 487 W TX power (not as much as it could be for the planned TX time though).

Now, message parameters:

f = 2970.1 Hz
Start time: 06.APR.2019  20:25:00.3 UTC
Symbol period: 6 s
Characters: 7
CRC bits: 16
Coding 16K21A
Antenna current: 2.4 A
Duration: 02:04:48 [hh:mm:ss]

Reports welcome :-)

73, Stefan



Am 06.04.2019 20:32, schrieb Markus Vester:

Hi Stefan, we'd like to look from DL0AO. Could you advise on time, exact frequency and message parameters?  73, Markus


-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 6. Apr. 2019 14:05
Betreff: Re: VLF: Ground loop improvements and test carrier...

Hi Paul,

Thanks for your measurements.
Good idea to calculate B relative to I.
Would be interesting to see how this varies with frequency.

BTW i did now actually order one of those:
https://www.dhgate.com/product/60-v-60ah-lifepo4-60-v-60ah-lifepo4-de-litio/445395613.html#s2-21-1b;searl|3512104843
Wonder how long it takes to arrive here, and even more, if it actually
has 60 Ah at 60V, i.e. 3.6 kWh!! If so, i will order 3 more of them!...

Considering the 13 dB advantage of night/day in recent transmissions
with that ground loop antenna, at least on 8270 Hz, I'd like to try a
night transmission tonite, at 2970 Hz, trying a 7 character EbNaut
message. So far we have no message decode at ULF between DL and UK. I'd
like to reach that mile stone and think the ERP should be fine now, but
hopefully the QRN stays low enough.

Everyone else is invited to try as well!!!

73, Stefan

Am 05.04.2019 19:06, schrieb Paul Nicholson:
>
> Stefan wrote:
>
> > These were the transmissions today (+ some more parameters):
>
> Received at 5170.1 Hz,
>
>  2019-04-05_10:39,+35m: 1130m, I=2,39 A, 0.63 fT S/N -5.07 dB/1Hz
>  2019-04-05_11:19,+51m: 900m, I=2,92 A, 0.63 fT S/N -4.92 dB/1Hz
>
> Yes, the same fT in both tests.  Then we have
>
> 900m
> ----
>  2.74 A -> 0.50 fT,  0.182 fT/A
>  2.92 A -> 0.63 fT,  0.216 fT/A
>
> 1130m
> -----
>  2.12 A -> 0.50 fT,  0.236 fT/A
>  2.39 A -> 0.63 fT,  0.264 fT/A
>
>
> Nothing received at 970.1 Hz.
>
> --
> Paul Nicholson
> --
>