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Темы - rw3adb

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1
Смотрю, они там приспособились довольно длинные сообщения уже слать... - [VLF TU DECODE]
Так за пару тройку ночей можно и QSO провести!)

Hello Riccardo,

Very nice! No problem to decode again. Best result was:

found rank 0 ber 3.5227e-01 Eb/N0 2.4 M -8.090035617e-02 ph 48 60,30,30,0 [VLF TU DECODE]
carrier phase: -5.9 deg
carrier Eb/N0: 2.8 dB
carrier Es/N0: -10.94 dB
carrier S/N: 21.52 dB in 37.9 uHz, -22.70 dB in 1Hz, -56.68 dB in 2.5kHz


This morning the QRN was very very low, it invites to transmit something. I should think about it this weekend :-)

73, Stefan

PS: Don't stop transmitting if possible :-) I like the messages a lot. And as you can see, a 20 charcter message would have been easily possible in the same time!


Am 26.11.2019 20:28, schrieb Riccardo IW4DXW:

    Свернуть

    Hi VLF,

    I think I've solved the isolation trouble.
    So, before another day of bad WX, I'll try again another message:

    f = 8270.003 Hz
    Start time: 21:00:00 UTC
    Symbol period: 15 s
    Characters: 13
    CRC bits: 12
    Coding 16K21A
    Duration: 7h, 20min
    Antenna current: 660 mA

    Reports are welcome.


    All the best

    73 de Riccardo IW4DXW

2
Splendid work, Stefan! Thanks for the details of what must have been the first
amateur VLF message across the globe.

It seems the VLF TX on this end is behaving itself again, thanks to
your guidance. It was good to have some company from Riccardo on Paul's
spectrograms. A bit of tinkering is still needed here before EbNaut can
be attempted again.

73
Joe VO1NA

On Tue, 12 Nov 2019, DK7FC wrote:

    Свернуть
     Hi Joe,

     Yes, the carrier transmissions were done to get an impression if and when the
     path is stable and if this is reproducable over a few days. I transmitted
     carriers for a few hours and later i tried to decode EbNaut '*' messages with
     different start times and symbol lengths.
     The results were plotted in an Excel sheet (attached) and we found that, when
     stacking 4 days, that a 3 hour long transmission starting at 17.55 UTC would
     give the best SNR of about 12.5 dB. One week later, the situation would be
     different since the path is very dynamic and the sunrise/sunset times are
     changing permanently. It looks a bit weird but in the end we managed to
     decode a 1 char, a 2 char and a 3 character EbNaut message.
     The antenna current was 1.2 A. I had some PA problems, EMC and so on. The
     antenna should have managed 3 dB more signal.
     Meanwhile the special licence for that band expired.

     73, Stefan

3
Yaesu FT-897D c TCXO
Yaesu FT-857D c TCXO
Yaesu FT-817ND
Yaesu FT-991A
Yaesu FT-990
Kenwood TS-2000 - требуется доработка приемника.
Kenwood TS-590 - требуется доработка приемника. (работает на передачу 1 мВт)
Kenwood TS-850S
Kenwood TS-480 - требуется доработка приемника.
Icom IC-756PRO
Icom IC-746
Icom IC-7000
Icom IC-706MK2G - прием на ДВ не очень, но принимает.

Начинаем дополнять список.
Считаю тему полезной для новичков.

Детали по доработкам приемника- перепайка или установка-снятие перемычек- смотрите в тексте ветки.

4
С праздником, геноссен!

5
ДВ антенны / Антенна Луиса EA5DOM
« : 26 Сентябрь 2019, 23:58:32 »
Луис мне прислал тут письмо с описанием своей антенны.
90м вертикал.
Насколько я понял, конструкция похоже на ту, что испытавл недавно Андрей RN3AGC  - удочка с балкона и два провода параллельно вниз.
Заземление- трубы холодной воды.
Только живет он повыше, потому и эффективность антенны получлсь в разы повеселее.
Пишет, что усилитель перенес  на терасску крышы, я так понимаю чтобыне шумел вентиляторами и не мешал домашним спать и готов вещать чуть не круглосуточно. -)

Оригинал ео письма:

Привет Роман !

I have answered in the Russian group. Hope Google translator is not extremely bad on Russian
I'm using English->Russian translation, which should work better than Spanish->Russian

Hope to get the PA working in the top terrace soon. So I will be able to keep it running all night long
without fan noise at home. And then we will be able to get the good openings at sunrise in your QTH

I read that you don't understand how my antenna work. May be I can explain you, so you can translate

I live in a 26 floor building tower. The top terrace is flat (no roof with tiles) and about 80m to the ground
Then I have a 10m fiberglass pole. The pole supports a vertical wire and two sloppers to provide some capacity
about 150pF. The coils to resonate the antenna are also in the top terraza and the PA should be there. Actually
is feeded by a coax from QTH in the 16 floor

So fa so good. But the ground of the coax or PA is connected to a metal pipe which runs down the building to
the basement. This pipe is part of the fire extinguish system and is filled with presurized water and in the basement
connects with the main water distribution grid

So this is a 80m pipe which is not just ground but part of the antenna. The high voltaje runs from the coil to the 10m
fiberglass pole and sloppers. But from PA ground to the basement only RF current runs trought that pipe

The result is that the whole pipe is part of the antenna and radiates. So the effective size of the antenna is 80+10m
The performance is very very good. I have not being able to calculate the real radiation resistance, but should be high
And with 3A RF this antenna should be radiating a few watts. That's why my signal is strong

Another important thing is the radiation angle, which should be low, as the building is hight and isolated from others
and also the nearby mediterranean sea can help for a good takeoff to Reunion island, for example

73 de Luis
EA5DOM

А это результат его работы:

http://136.su/index.php/topic,18.msg24947.html#msg24947

http://136.su/index.php/topic,18.msg24937.html#msg24937

Усилитель мощностью 1300Вт


6
Технический раздел / UA4AAV set-up. PA, ANT, LOAD COIL, ect
« : 19 Сентябрь 2019, 22:57:52 »
Коллекивно решили собрать все ссылки по сетапу Виктора в одной теме.

Начиналось всё отсюда:

http://136.su/index.php/topic,74.msg24280.html#msg24280

Power Amplifier./Усилитель мощности:

http://136.su/index.php/topic,74.msg24283.html#msg24283

http://136.su/index.php/topic,74.msg24288.html#msg24288

Fan cooling system/Система охлаждения:

http://136.su/index.php/topic,74.msg24289.html#msg24289

Input  transformer 1:16/Входной трансформатор 1:16:

http://136.su/index.php/topic,74.msg24290.html#msg24290

http://136.su/index.php/topic,74.msg24339.html#msg24339

Anode current.Ток Анода:

http://136.su/index.php/topic,74.msg24293.html#msg24293

Antenna current/Ток антенны:
Maximum on ammeter 25A

http://136.su/index.php/topic,74.msg24294.html#msg24294

Output transformer/Выходной трансформатор:

http://136.su/index.php/topic,74.msg24340.html#msg24340

Circuit diagram/Схема:

http://136.su/index.php/topic,74.msg24338.html#msg24338

Antenna:

http://136.su/index.php/topic,74.msg24286.html#msg24286

Load coil/Удлиняющая катушка:

http://136.su/index.php/topic,74.msg24297.html#msg24297

Bushing/ Проходной изолятор:

http://136.su/index.php/topic,18.msg24849.html#msg24849


7
Помнится, была такая софтина Рика Стробе, которая сама по заданным ссылкам сгружала картинки с грабберов. (Кто знает где скачать - ссылку сюда.) И складывала в архив.
Может у кого-то есть простаивающий старенький комп, И возможность выкладывания ежедневного архива на яндекс-диск или майл-ру облако?
Нужен надежный интернет, чтобы "ни единого разрыва" и компик типа сокет-478, хоть под чем, можно ХП.
Все это запилить в автоматическом режиме вполне реально...
У меня не очень надежный интернет, а то бы может и сам занялся.

8
Посколь RSGB LF накрылась медным тазом с 1 сентября почему-то и не ясны перспективы ее починки, то предлагаю взять у Алана G3NYK список емейлов и позарегать всех тут.
И создать англоязычный раздел.
Сергея спрашивал об этом- но что-то нема ответа пока...
Надо как минимум создать или добавить на существующую страницу регистрации надписи на английском.
Ну и подразделы как  у нас типа на основном.
В дали форум наш не везде хорошо открывается, некоторые жаловались, но другой возможности у нас нет пока.

10
Here are results from the post-processing of yesterdays transmission at
5.17 kHz. RX sites at DK7FC (tree) in 57.6 km distance and DL0AO in 283
km distance. Mixing the two orthogonal loops at DL0AO allowed to steer
the resulting software rotatable loop into and angle where the SNR
became as good as it can be for that day and time. Now the message is
completely readable in 283 km distance (4.8 wavelengths). Two versions
of the result at DL0AO are shown, one from DK7FC.

TX site: 1130m spaced ground electrodes in JN39WI | 1.7 A antenna
current at 370 W TX power (higher losses due to dry soil, thus less
power from the given antenna voltage at the PA)

73, Stefan

Am 03.08.2019 18:08, schrieb DK7FC:

    Свернуть
     BTW today i transmitted "73" in QRSS-240 at 5.17 kHz, starting 08:30
     UTC. There was a team from a TV channel (Bayerischer Rundfunk) at the
     VLF RX site of DL0AO and they followed the QRSS coming in on the
     spectrogram. I hope they will report about it then...
     Unfortunately it took 1.5 hours to fix two broken wires of the
     antenna. Afterwards the QRN already set in, so half the message was
     lost in the noise... Anyway, the 7 is quite doubtless.

     73, Stefan

11
LF: MF Frame antenna
Когда: 4 августа в 12:56
Кому: rsgb_lf_group@blacksheep.org
От кого: Joe df2jp

Hello, folks,

 

since my QTH has changed and the antenna possibilities are rather bad, I decided to build an RX-frame antenna.

During a conversation with Peter, DC0DX on UHF :op it turned out that Peter still had a meander-shaped frame antenna in the corner. the cross has 150cm. In the course of the conversation the question came up: Isn't it also possible to transmit with it? Should work, you only have to add another C to the coupling loop to adapt it to the TX.

Since my frame isn't finished yet, Peter did the first tests at the weekend.

 

2019-08-03 09:24  DC0DX  0.475725  -6  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 09:08  DC0DX  0.475725  -28  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 08:54  DC0DX  0.475725  -7  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 08:38  DC0DX  0.475725  -7  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 07:24  DC0DX  0.475725  -19  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 07:08  DC0DX  0.475725  -18  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-03 06:38  DC0DX  0.475725  -19  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0



2019-08-02 22:54  DC0DX  0.475725  -20  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-02 22:38  DC0DX  0.475725  -22  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-02 22:08  DC0DX  0.475725  -22  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0
2019-08-02 21:54  DC0DX  0.475725  -27  0  JO31lk  0.001  DC5AL-R  JO31lk  0  0

The two stations are only 5 km apart, transmission power approx. 500 mW, transmission location in the Shack!

Until 08.30 o'clock the loop was directly connected, from then on the 2nd Dreko was added, you can see the difference.

At 09:03 Peter had turned the frame by 90°.

 

Here is a picture of the experimental setup

 

 

I find this very remarkable, considering the holiday and summer time there is hardly anyone qrv on MF, with the loop optimized until autumn some stations should already be added.

 

73 Joe

12
Технический раздел / MT-Hell Standalone
« : 25 Июнь 2019, 23:31:50 »
MT-Hell Standalone

G8HAJ has designed a standalone MT Hellschreiber interface that uses a small 14 pin 16F1615 PIC device.  It can be used either to send a beacon message or inreal time QSO mode using RS232 interface from a terminal.

The speed / bandwidth is made continuously variable from a few 100Hz down to fractions of a Hz using a pot to control the settings.  Which makes it useable at LF

The downside is that it uses a hybrid SMT/CMT which he calls Pol yPhase or PP/MT-Hell type of modulation that does require a linear transmitter - so no high power with a switch mode Tx   

More details and a full description and PIC firmware download at Graham's web site  http://g8haj.uk/    or specifically   http://g8haj.uk/?page_id=288


Four of us using that module recently had a simultaneous full-quadplex (4 way version of duplex :-)  QSO on the QO100 satellite.    A few screen dumps of the QSO underway showing all four stations can be seen here :
http://www.g4jnt.com/DropF/new14.tif
http://www.g4jnt.com/DropF/new18.tif
http://www.g4jnt.com/DropF/new27.jpg
http://www.g4jnt.com/DropF/new29.jpg




Andy
www.g4jnt.com

13
Довольно гениальное изобретение нашего камрада и геноссе Йорга!

Пробил расстояние 70км!

Говорил, что светодиода уже не видно, а демодуляция идёт все равно!
Игрался на расстоянии 150м - уменьшал мощность.

http://dl0rcp.bplaced.de/index.php/themen/48-lichtfunk-lichtsprechen-lichtbaken

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