форум Радиолюбительского ДВ портала > Технический раздел
Удаленные приемо-передающие позиции
rw3adb:
к нам в копилочку.
Стефана поздравляем с почином.
Такой вариант пройдёт не у всех, конечно, но вдруг будет кому-то полезно?
Кстати, рекомендую полезное что-то из рассылки РСГБ отмечать здесь.
Иначе, там в последствии будет затруднительно что-либо найти, даже обладая архивами рассылки за много лет.
Hi all,
Today it is the first day that my remote receiver is running while hanging 15m AGL into a tree in my garden outside the city. It is streaming audio from a MF/630m receiver via WLAN over 2.4 km distance to my home location!! :-)
Since 16:30 UTC, the link is running :-)
It is a large step in this project but not the last. So far, no antenna is connected to the RX, i still have to lay the cable up into the tree :-) I am checking the stability/availability of the GHz link and the watchdog scripts, hopefully keeping the link to the remote end.
There is a website (not up to date) giving more explanations: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_remote_Grabber_info.html
If all runs well i will be back tomorrow to connect the antenna to stream first MF signals from the garden :-)
It is not only a RF remote link project. Additionally it became a project for solar energy systems, i am monitoring the solar battery system voltage to do some energy management. I'm now getting good impressions and a better understanding what energy input can be expected from a cloudy day (10%, 50%, 100% cloudy) relative to a sunny day, or the difference between February and April! A circuit protects batteries from deep-discharges by swicthing the power supply of the Raspberry Pi OFF but before that, it gives a HIGH level on a GPIO pin of the Raspi. A script is running on the Raspi which correctly shuts it down if the input becomes HIGH for > 3 s. This happens at <= 11.2V. But the best is that at 12.8V, the hysteresis of the circuit switches the supply voltage ON again, which automatically starts the Raspi again! So, in a longer period of cloudy days, the energy of the batteries may be insufficient. But this should neither cause unwanted crashes of the system nor deep-discharge the batteries, it just affects the availability of the system, which can be improved then. This circuit consumes < 50 uA.
The 12V supply voltage is measured by a LTC2400. Each 30 seconds a measurement is done. 2 averages of a measurement is saved into a text file (each minute) which is automatically syncronized by btsync software over the WLAN link. So finally the text file is available on a local PC here which runs LabView software which generates a voltage-over-daytime plot, automatically generates a png image which is saved to the webserver which is running this website: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_remote_Grabber.html
This is fascinating stuff for me. And i can now optimise my solar system parameters. Do i need to install more solar peak-power or do i need more batteries, or both? These questions can be answered fairly easily now by studying the plots.
The overall power consumption of the system is 3W. It is now running on 2x 7 Ah 12V lead acid batteries. One of them is 7 years old ;-) I'm hoping for a stable link and seeing the voltage rising again tomorrow morning :-)
Another funny feature is: I can remotely switch a bistable relay (energy saving) which switches the input of the USB soundcard. One input is the RX, the other one is a microphone which is installed into a feed-through of the waterproof box. So i can decide to listen to MF or to the birds singing in the morning, or to wild pigs at night, destroying the lawn! SpecLab and it's triggered event function could be used to detect and record sudden nightly audio events :-) It is even possible to send a SMS if this happens so i can listen to the web-radio steam on my smartphone out of the bed :-) Crazy world!
Two up to date images
https://dl.dropboxusercontent.com/u/19882028/MF/20150411_181847.jpg
https://dl.dropboxusercontent.com/u/19882028/MF/20150411_184112.jpg
To be continued...
73, Stefan
Сергей UB1APE:
Впервые за эти годы прочитал всю тему целиком. Это ж сценарий для фильма! Кла-асс! Очень понравилось. Спасибо RN3AUS.
rw3adb:
Светлой памяти "Лунохода-1" RN3AGC - посвящается.
rw3adb:
Стефан, гляжу, реализовал мою давнишнюю идею "музыкального скворечника"...
в наших местах, конечно подобная конструкция и дня не проживёт, скорее всего, но думаю, что может кому то будет полезно:
Hi all,
For those who are interested, here are a few new images of my remote RX
installations in the new location.
https://www.dropbox.com/sh/4rdxmsly71xqsjw/AABnc6CddUTH3AuZPxpkgYzMa?dl=0
There is some good progress! Today i installed the waterproof box and
started the new Raspberry and established the WLAN link for the first
time. It runs all very well so far and i love to stay up there in the
tree on that hill/mountain, where stress noise is unknown!
Next steps are to order more batteries and solar modules and to build a
first MF receive antenna...
73, Stefan
Пока спросил его по части софта, что и как реализовывал, какая ось, проги?
У него там основная заморока, чтобы с одной стерео-звуковой получить два разных потока по каналам... думаю, для нас это вторично и более важны иные вопросы.
rw3adb:
отмечу такую проблему удаленных позиций на принципе потокового вещания звука в сети/интернет: задержка принимаемого сигнала.
Стефан столкнулся с ней даже при использовании вайфая на небольшое расстояние.
ЩРСС все это как то пофиг, а вот цифра... в результате, вспр нормально не декодируется и необходим тайм-шифт в программе.
Стефан пишет, что в ранних версиях это было доступно, а в новых нету такой опции и возникает целая проблема.
Am 02.10.2015 09:23, schrieb Andy Talbot:
> Why would you want to do that ?
> Andy
...because i need to stay inside the +6.5 second maximum offset time for
WSPR. MF is coming from my garden, as a vorbis audio stream via the web,
is pre-processed in Spec-Lab, fed two times to VAC etc. This causes a
time offset of at least 3 seconds (displayed in WSPR) but can be even
longer. Recently, for some unknown reasons, the offset becomes more than
6.5 seconds. I just want to have the possibility to correct that in an
easy way. Actually a task for the WSPR software!
73, Stefan
вообщем, немножечко слежу за темой, по возможности, важное буду выкладывать сюда.
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