BATC Forum

Hi All

This week i managed the first LIVE Digital television transmission with the Poor Man's DATV Transmitter.
Nothing is perfected yet but it does make live video possible which is what most people are after!

See the info here:
http://www.m0dts.co.uk/datv.htm

Hope to see you on DATV soon..hi

73

Rob
M0DTS

Good work Rob - well done

Rob
Well done , I did see that French site a year or so ago,was very impressed with possibilties, but thats as far as I went I am afraid....
Great job.When are the kits out ??

Richard - G8BYI

g8byi wrote:Rob
Well done , I did see that French site a year or so ago,was very impressed with possibilties, but thats as far as I went I am afraid....
Great job.When are the kits out ??

Richard - G8BYI

The original design took a lot of getting running when i built it but this version is a lot easier and runs in windows/linux so is a lot easier to use!

The whole setup is still much of a work in progress but maybe sometime i will consider makiing some boards.... we shall see..hi
Curerent thoughts are to make a board with USB in and 436MHz Digital RF out at ~10mW. For other bands you just mix the output up to suit.

Anyone else have any ideas?

73

Rob

I have just received an SDR kit from Ettus Reasearch in the US for a project at work to do with DAB radio.
see http://www.ettus.com/download

It has a USB input for it's data, and RF modules can be ordered for frequencies up to about 2 GHz

Not that cheap, (about US $700 fro the basic kit including a case) but I have seen it working as a DAB transmitter at IBC this year using just a laptop running Linux, (see CRC website http://www.crc.gc.ca/en/html/mmb/home/home ) no reason why it couldn't do DVB either.

Andy EI3HG
Waterford, Ireland

Hi, and Merry Christmas to all...

Just a note to confirm that Rob's (M0DTS) Poor Mans DATV implimentation is a
really worthwhile system to build. The hardware designs for the Serialzer and the IQ
Modulator shown on his Web site worked fine for me, after sorting out my own inflicked
errors.
Rob's latested Linux implimentation that uses a PVR 150 type mpeg2 encoder card
with ffmpeg and gbdvb applications, has produced for me a workable DATV system, be
it that I have no one round here to test it with as yet..
It has a 1 to 1.5 second delay from realtime , but in reality, for a simplex contact this is
not an issue. I achieve 2Ms/sec using a dual core 2.8ghz IBM ThinkCentre miniPC running UBUNTU v9.04.

I had and still have a large learning curve in the use of UBUNTU /Linux, but I am getting
there , it must be said with a great deal of help and patience from Rob (M0DTS).
I produced the hardware onto two pcbs, they work fine, though the serializer has got 10
wire links of various lengths on it, since I am only comfortable in producing single sided
pcb's with a ground plane.

Anyway I recommend Rob's design to others, it is a cheap way to get going on DATV,
and has real scope for 70cm use.

73
Richard G8BYI

Hi All

In the last few days i have improved my Digital ATV system and Live video is now working well at 2Ms/s.

See the info here:
http://www.m0dts.co.uk/datv_live.htm

I hope some more of you get building it now

73

Rob
M0DTS

Building on Rob's excellent work, last night I managed to generate
and decode (on a DVB-S set top box) 2 Msps R = 1/2 DVB-S DATV
using GNU-Radio and a USRP2 SDR from Ettus Research.
Only a couple of small changes needed to be made to Rob's files
and about 15 lines of Python written to control the USRP2 /WBX.

The output was a few mW @ 1.3 GHz

- Charles G4GUO

Hi,

I recieved my usrp2 a few days ago...
Are you willing to share your code with me?

i'm using already sr-systems and digilite. but want to test also with usrp.

thanks
on4bhm
73's

Yes I can let you have a tar file. Please remember that it is still work in progress.

You may have some difficulty in building the software as it is using some non
standard libraries (principally FFMPEG will need rebuilding to include some extra
codecs). Also it probably won't work with the latest version of Qt4. I am waiting
for the official release of Qt5 before I change all the project files (again).

The only other thing I ask is that you don't post the code onto the Internet as
it is not under configuration control yet and I don't want loads of unofficial
versions being posted by other people (the chance of that happening is slim).

As far as the USRP2 is concerned you will need to have the UHD driver installed.

I can't give you much help as I am a bit busy at the moment but if you really
get stuck I will try to give you some pointers.

- Charles G4GUO