This is a picture of my Linux box running transmit and receive on DVB-S.
Top left is the Xine display window showing a live picture, below that is the
DVB-S transmit program, to the right of that is the DVB-S receive program
(actually it controls a DVB-S card) and above that is the system load.
Here is a front and back picture of the nearly completed DATV Sender.
My first job was working for BBC Transmitter group this is why it is a
Sender rather than a transmitter.
Those of you that are not yet on digital TV, you don't need a radio this big to
get on. I have just been watching too many Hot Rod programs on Quest!
Well some progress, I have managed to write a simple program
using the DVB API to tune my S2-3600 dongle and to output
TS data (both video and audio) to the DVR device. Then read the
DVR byte stream and output that into a fifo which I can then open
using Xine and Voila I can receive DVB-S. I am certain there is a
better way to do all this.
I also got the Alford slot up on a pole in the backyard and can now
transmit DTV into a proper antenna. This is just a temporary antenna
but should be good enough for me to share pictures with the very locals.
When I have re-arranged all the junk in the 'transmitter hall' I will boost
the power from 0.5W to about 12 W. Well that was my weekend.
I managed to get my QT4 app to open an embedded player window
and then play a movie file from disk. Next I will have to get the app
main window and the video window to appear as one program rather
than two floating windows. Then I will need to add the various buttons
to control the DVB-S/S2 dongle then pipe everything together to display
the received signal.
Of course the version of VLC from Red Hat is not the latest and the VLC
guys have changed the interface spec. Oh how I love Linux. I will just use
the old version of libraries for now.
I managed to get Jean-Pierres Tutioune program to work on the small dual
core Atom P.C that I built last week. With a bit of fiddling it locks onto the DVB
signal but as yet I have not managed to get a picture despite getting a good
lock and not dropping any transport packets. Tutioune seems to have a fixed
sized and my screen is quite small so it does not look very good at the resolution
I am using. I know how difficult it can be to write programs that work properly
on all screen sizes.
I am starting to get a fair amount of interest locally in digital TV so I am going to
have to get the Alford slot I bought up on a temporary mast just to give the locals
a test signal before they all loose their enthusiasm.
After talking to Jean-Pierre F6DZP about his Tutioune software.
I had another look at the S2-3600 DVB-S/S2 USB dongle I bought.
I have managed to hack some code, that using the Linux DVB API
can tune the dongle to 1.3 GHz and lock onto my SDR generated DATV
signal. Next I am going to have to look at embedding Video inside a
QT4 application so I can make a homebrew DATV receiver. Most of the
Linux Apps for DTV are designed for broadcast reception and are not
convenient for amateur use. I have found an example of using the VLC
library for embedding Video so I will have a hack at that.
I will keep the transmit app and receive app separate
In my pursuit of transmitting a decent DATV signal I have
decided to apply for planning permission to install a telescopic
mast at the G4GUO QTH. I have paid my £30 for pre-planning
advice and now await to be assigned a case officer. My application
is very modest, low profile mast and some UHF/SHF antennas.
I have done an artist's impression of the antenna and included
that with the other details.
In the past I have not bothered with planning permission and have
not had any complaints from my neighbours but as I am going to have
to spend a fair amount on the 'antenna support structure' (mast)
this time I thought it would be better to go the whole way and do
the job properly.
I used to have a 3 ele HF yagi on a pole attached to the end of the house
but in 1986 the winds blew, the antenna came done and brought with
it part of the wall of the building. Thankfully the insurance paid for the
damage. This time I aim to use a free standing mast!
This is a picture of my Linux box running transmit and receive on DVB-S.
