Эксперименты на 8.97 кГц

[Р6ЛДД]

Без слов. Снимаю щляпу!!! 

[andrey rd4hu]

Александр прими и мои поздравления ! 5кГц это уже запредельно для любительской связи .
Стефан прислал мне mail , строит новый мощщнючий VLF оконечник ! на следующей неделе будет пробовать на 8кГц !

[andrey rd4hu]

DK7FC прислал фото антенной катушки на 5кГц 

[Sergej]

Известный длинноволновый энтузиаст жо1на был принят на 8кГц в Англии:

http://www.southgatearc.org/news/2017/october/canadian-radio-hams-10uw-erp-8-27-khz-signal-heard-in-uk.htm

[rn3aus]

В журнале Радио № 11/2017 опубликована первая часть моей статьи о наших экспериментах на СДВ. Продолжение в декабрьском номере.

[rn3aus]

Внимание! На диапазоне 8270 новый рекорд! Передачу Стефана принял Андрей RD4HU!
2877 км между DK7FC и RC4HAA
Поздравляю!!

ebnaut-rx V0.7b
input file C:\EbNaut\05_NOV_2321_8270.wav
sample rate 0.342938 per second
rx frequency 8270.1
file start time 2017-11-05 16:43:23.800
polynomial 8K19A
crc size 6
number of chars 1
block size 12
symbol period 180.000
number of symbols 240
list length 49
start offset 468.200
freq offset 0.000000
cores 2
skipped 469.472616 seconds to start
initial reference phase 3.6
---------------------------------------------
found R
list rank 0
reference phase 0,0,0,0
carrier S/N 12.53 dB in 23.1 uHz, -33.83 dB in 1Hz, -67.81 dB in 2.5kHz
carrier Es/N0 -11.28 dB
carrier Eb/N0 4.97 dB
info bit period 7578.95 seconds
symbol error rate 86/240 = 35.833 %
Es/N0 from symbol errors -11.8 dB
Eb/N0 from symbol errors 4.4 dB
Shannon capacity 2.1 bits/hour
Shannon efficiency 22.9 %
symbols file C:\EbNaut\05_NOV_2321_8270-symbols.csv
elapsed 1 seconds
---------------------------------------------
found R
list rank 0
reference phase -30,-30,-30,-30
carrier S/N 12.53 dB in 23.1 uHz, -33.83 dB in 1Hz, -67.81 dB in 2.5kHz
carrier Es/N0 -11.28 dB
carrier Eb/N0 4.97 dB
info bit period 7578.95 seconds
symbol error rate 84/240 = 35.000 %
Es/N0 from symbol errors -11.2 dB
Eb/N0 from symbol errors 5.0 dB
Shannon capacity 2.1 bits/hour
Shannon efficiency 22.9 %
symbols file C:\EbNaut\05_NOV_2321_8270-symbols.csv
elapsed 4 seconds
---------------------------------------------
found R
list rank 0
reference phase 0,0,-30,-30
carrier S/N 13.01 dB in 23.1 uHz, -33.35 dB in 1Hz, -67.33 dB in 2.5kHz
carrier Es/N0 -10.80 dB
carrier Eb/N0 5.45 dB
info bit period 7578.95 seconds
symbol error rate 80/240 = 33.333 %
Es/N0 from symbol errors -10.3 dB
Eb/N0 from symbol errors 5.9 dB
Shannon capacity 2.3 bits/hour
Shannon efficiency 20.6 %
symbols file C:\EbNaut\05_NOV_2321_8270-symbols.csv
elapsed 14 seconds
---------------------------------------------
found R
list rank 0
reference phase -30,0,-60,-30
carrier S/N 12.99 dB in 23.1 uHz, -33.37 dB in 1Hz, -67.35 dB in 2.5kHz
carrier Es/N0 -10.81 dB
carrier Eb/N0 5.43 dB
info bit period 7578.95 seconds
symbol error rate 79/240 = 32.917 %
Es/N0 from symbol errors -10.0 dB
Eb/N0 from symbol errors 6.2 dB
Shannon capacity 2.3 bits/hour
Shannon efficiency 20.7 %
symbols file C:\EbNaut\05_NOV_2321_8270-symbols.csv
elapsed 75 seconds

[Сергей UB1APE]

!!!!!!!!!!!!!!!!

[andrey rd4hu]

Внимание! На диапазоне 8270 новый рекорд! Передачу Стефана принял Андрей RD4HU!
2877 км между DK7FC и RC4HAA
Поздравляю!!

спасибо Александр ! моя роль в этом малая , но тоже очень рад долгожданному успеху !

[rn3aus]

В журнале Радио № 11/2017 опубликована первая часть моей статьи о наших экспериментах на СДВ. Продолжение в декабрьском номере.

Вышло окончание статьи в "Радио" № 12/2017.

Статья целиком.

Все материалы: http://136.su/index.php/topic,199.msg9575.html#msg9575

[rn3aus]

На СДВ в этом сезоне на передачу работают: DK7FC, DF6NM, VO1NA, W4DEX, IW4DXW.

Интересные мысли из рассылки:

Added to the growing list of amateur achievements
at VLF

  http://abelian.org/vlf/amateur-radio/

It has been a very successful season so far. I hope this
encourages more people to have a go at VLF, we need more
transmitters and receivers.

Perhaps the perception is that it is difficult? Surely not.
Don't believe all those stories you hear about how hard it is
to radiate, or how difficult it is to find a location to
receive from!

Let's see -

- Low cost. You don't need expensive SDRs or test equipment.
   Your PC soundcard is signal generator, spectrum analyser,
   and SDR, all in one. Transmitter is just an audio amplifier,
   even a low quality one. The most expensive thing you'll buy
   is a load of wire for a loading coil.

- GPS timing? £18 quid for a NEO-7 module and you know your
   frequency to the micro Hertz. Buy two, you'll use them!

- Easy to build. Just audio frequency signals, nothing critical
   about layout. VLF is great for the homebrew enthusiast.

- You don't need a huge ERP. 10uW and you're on the air. Your
   LF antenna will probably do better than you think at VLF.

- UK Notice of Variation? No problem, a simple application form,
   and if enough apply, maybe the regulators will make that easier.

- Where else can you operate at the cutting edge with such
   simple equipment?

In case you thing my location here is specially good, it certainly
isn't. The mains here at the top of the Calder Valley is very
rough, terrible sidebands. All the properties around here get
their power by overhead lines at 12kV and one of the two 33kV
lines feeding Todmorden is only a km away. The nearest 12kV
line is just 120m from the E-field antenna. 140mV RMS of 50Hz
on the E-field probe and a lot of harmonics. Reception here is
bad! You can probably do better in the suburbs.

How many times per century does amateur radio find a green field
to explore? Not just a new band but a whole new frequency range.

Don't miss out on this one!

--
Paul Nicholson

Indeed!
Recently i thought "VLF is the new LF".
 From the view of a HF amateur, LF is complex because of the large
coils, the high voltages, the sepcial narrow band modes, the genaration
of stable frequencies, the few number of active stations... Oh and it is
sooo deep! Actually it can't work. Oh, and why do these crazy OMs use
such low frequencies at all? The 20m band is so much easier ("Youuure
5ee9e", "CQ DX"...)...
VLF is just another step in this direction. The coils are larger, the
voltages higher, the ERP lower, the frequency must be even more stable,
the modes are even more narrow...
AND, not to forget, like HF->LF, LF->VLF is a few orders of magnitude
more fascinating, exciting, exceptional!
I can see only positive tendencies, the lower it goes :-)

73, Stefan

[Р6ЛДД]

In case you thing my location here is specially good, it certainly
isn't. The mains here at the top of the Calder Valley is very
rough, terrible sidebands. All the properties around here get
their power by overhead lines at 12kV and one of the two 33kV
lines feeding Todmorden is only a km away. The nearest 12kV
line is just 120m from the E-field antenna. 140mV RMS of 50Hz
on the E-field probe and a lot of harmonics. Reception here is
bad! You can probably do better in the suburbs.

Я так понял, что по приему там не совсем подарок.

[rn3aus]

Друзья! Я принял VO1NA! http://136.su/index.php/topic,366.msg20721.html#msg20721

[Сергей UB1APE]

Ё!!!! Я тоже хочу-у!

[rn3aus]

Статьи по тематике СДВ с Польского сайта:

A few months ago i've written 3 articles (in english and polish) for the
klubnl.pl site describing vlfrx-tools usage for vlf monitoring (both
hardware and software. This might be complementary to Alex's article which
describes using Spectrum Lab on windows.


hardware setup:
https://klubnl.pl/wpr/en/index.php/artykuly/sprzet-do-monitorowania-vlf-za-pomoca-vlfrx-tools/

1pps signal source:
https://klubnl.pl/wpr/en/index.php/artykuly/proste-zrodlo-sygnalu-1pps/


using vlfrx-tools:
https://klubnl.pl/wpr/en/index.php/artykuly/uzywanie-vlfrx-tools/

(Paul, sorry for the naiive examples, this could have been written much
better



this might also be interesting:
https://klubnl.pl/wpr/en/index.php/2017/06/24/dekodowanie-7-znakowej-wiadomosci-na-6470hz/

Jacek Lipkowski

[ut7gh]

https://sites.google.com/site/sub9khz/vlfnews-2018