Re: LF: 1476 kHz AM - temporarily off

[Markus Vester <markusvester@aol.com>]

Thanks once again for all who reported or attempted reception of Ralph's emission over the last weekend. We were stunned and positively surprised by the number of feedbacks and amazing results. Radiated carrier power was approximately 3 W EMRP (~ 9 W EIRP).

Unfortunately Ralph had to temporarily take the transmitter off air at 14 UT today, awaiting installation of some dedicated control infrastructure at the site. He hopes to resume continuous operation with music modulation in a week or two from now. As discussed, we are considering to implement slow carrier frequency modulation to assist weak-signal identification.

Best regards,
Markus (DF6NM)
 

-----Ursprüngliche Mitteilung-----
Von: Marcus PY3CRX PY2PLL <py2pll@py.qsl.br>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 11. Nov. 2018 13:42
Betreff: Re: LF: 1476 kHz AM

Hi Markus ...

Yes, I'll try next days assuming that the TX will be on using 1Kz on/off pattern or even with regular modulation relay as explained before.

But don't worry abt a paralell harness to help me verify frequency. I can run for some calibration periods another ARGO using one european KiWi SDR versus the swinging one.

Tonight at the last capture saw this varying signal fading out and a "big" change in frequency so I used a couple of european receivers to plot: Artic KiWi SDR and one from Greece. At the greek one this signal was strong enough to listen to AM TX. Seems a BC stn from Egipt.

When I wrote yesterday about Vietnam SDR etc I was only trying to see the coverage área for such BC at that present time and figure If I can count on it as a signature reference.

Now the propagation from SW Brazil to Europe: I detect here MW BC carriers at the SDR's spectrum analyzers / whaterfalls on a daily basis. But demodulating information is another subject :D. It's easier to receive some LW at 171, 189, 243 and 252 than MW here.

But the MW carriers are always there (our freq plan is one channel each 10K so ITU Reg 1 & 3 appears between them). At QRSS 30/60/120 we can really expect to dig some signals from the noise.

And to figure how unpredictable this path can be, I already detected DCF77 twice, DCF39 once or twice etc. I know they are VLF signals, another behaviour. But to detect this carrier - again - I'll need to keep this setup for days or even weeks. Like I did to recover LW NDB from South Africa, or Navtex from Easter Islands, etc.

On the other side our clgs LU and CX was already decoded / detected at 630m WSPR / QRSS at Europe/USA. Looks like the VHF transequatorial propagation =:D.

Lets see if the 1476K 1W EIRP (??) can show up agn.

Thanks for the support.

73
Marcus
PY2PLL + PY3CRX
GG66rf

Em 11/11/2018 08:43, Markus Vester escreveu:

Hi Marcus,

yes http://df6nm.darc.de/mf/1476kHz.jpg should have auto-updated every hour, except that unfortunately my PC stalled shortly after 4 UT.

The slow Argo is helpful. Comparing your 4:34 UT screenshot on OneDrive
https://onedrive.live.com/?authkey=%21AP9Llo5xGFVVaEM&cid=87CB17EDE8238CAA&id=87CB17EDE8238CAA%21150674&parId=87CB17EDE8238CAA%21133142&o=OneUp
to my last one
http://df6nm.darc.de/mf/1476kHz_181111_0400.jpg
we find that the swinger varied between +0.45 Hz (close to Ralph's frequency) and 0 Hz (nominal 1476 kHz). So it seems your display was around 0.5 Hz low at the end.

Unfortunately, this time Ralph's line did not appear near the upper boundary of the swinger waveform. Do you want to you try again tonight?

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Marcus PY3CRX PY2PLL <py2pll@py.qsl.br>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 11. Nov. 2018 3:05
Betreff: Re: LF: 1476 kHz AM

OK, may be the version I'm using have only 30/60/120 so I set it to 120 normal, 10 minute ticks.

Now 1:45 UTC ... the "swinger" seems to vary across Ralph's line. The link to 1476.jpg on your site is updated from time to time? Or it is a manual sample?

At one of my screenshots there's a thin line at 22:52 UTC, the moment when I switched to 60KHz to check freq cal. Then came back to 1476. Drift .1Hz for an not-ovenized lo seems ok for now. At least I figured that I can macth any freq within +/- 1.5Hz.

May be I put another SDR-IQ using DL4YHF SpecLab ... and learn how to make it locked to PPS :D

73
Marcus
PY2PLL

Em 10/11/2018 23:06, Markus Vester escreveu: