GB3TZ symbol rate

Ideas, technical topics, help and discussion for ATV repeater builders
Post Reply
Posts: 23
Joined: Fri Sep 02, 2016 9:04 am

GB3TZ symbol rate

Post by arthur21 » Mon Nov 02, 2020 6:25 pm

GB3TZ currently runs at 4ms/s QPSK from an SR Systems coder/modulator. This coder was originally set up by a serial port connection to an old laptop which has since been lost complete with the programming software. Can anybody help with the software which we think was called fw-tools and ideally remember how to use it. The unit we have in TZ produces 2 pages but we do not have any information on how to set up the second page.
We would also like to do some tests with the system set for 2ms/s or 1ms/s if it will go that low.
73 Arthur G4CPE

Posts: 29
Joined: Sun Nov 20, 2011 2:35 pm

Re: GB3TZ symbol rate

Post by ON1AVO » Mon Nov 02, 2020 7:23 pm

Arthur, I've sent you a PM.

Posts: 19
Joined: Wed Jun 18, 2008 8:46 pm

Re: GB3TZ symbol rate

Post by HB9DUG » Mon Nov 02, 2020 7:56 pm


HB9TV network runs with SR-Systems first generation which I think from you message regarding connecting to it with fw-tools is the same.

We have all the documentation as well as the latest and last firmware for it.

The lowest you can tx in DVB-S is 1Ms/s but you will have to change the TCXO (default 60 MHz) on the DVB-SC Mod 2TS or 4TS by one at 24 MHz if I remember correctly (I will check the doc when I am back home).

No problem to make you a package with all the info, let me know.

73 qro de michel, hb9dug

Posts: 23
Joined: Fri Sep 02, 2016 9:04 am

Re: GB3TZ symbol rate

Post by arthur21 » Mon Nov 02, 2020 8:33 pm

Hello Michel
We would be very grateful for the information package . We have a 2nd MPEG2 encoder card which we would like to fit if possible.
73 Arthur

User avatar
G1LPS Terry
Posts: 149
Joined: Mon Mar 10, 2008 10:33 pm

Re: GB3TZ symbol rate

Post by G1LPS Terry » Mon Nov 02, 2020 8:36 pm

Hi Michel
I have the 1st generation also with 4ts.
Could you send me the package also please?

Kind Regards
Terry G1LPS

Posts: 1332
Joined: Wed Apr 07, 2010 6:26 pm

Re: GB3TZ symbol rate

Post by g8gtz » Mon Nov 02, 2020 9:11 pm

Don't forget BATC is happy to support groups financially if they wish to upgrade to H264 / H265 by using either a Portsdown or a "H264 encoder box".


Noel - G8GTZ

Posts: 8
Joined: Fri Jan 05, 2018 6:02 pm

Re: GB3TZ symbol rate

Post by DL1BJV » Mon Nov 02, 2020 9:56 pm

Working on a similar problem here.
Our DATV repeater, DB0DP located at the University of Bremen, DL2VT Dieter is the keeper, uses the old (2003)
SR-Systems DVB-S/C Modulator 4xTS V2. Board. It has been working good for many years.
We want to change the SR from 4,7M/s to 2M/s. (We have changed the Oscillator on the board to 24MHz)
We have received a copy of datvfwtool.exe, the cygwin1.dll file, all working, and some Instructions from HB9AFO.
We will have to change the Config-File. (write a new one which we have done and hope that it will do the job but still
hesitating to press the button)
Our main problem is that we do not know the contents of the present Config file on the board.
Our big question, Is it possible to read out the stored config file and if so how?
We are using Putty to communicate with the board and get the the Info Data at start up.
An example of a config file and some instructions can be found here:
In French but can be translated.


User avatar
G1LPS Terry
Posts: 149
Joined: Mon Mar 10, 2008 10:33 pm

Re: GB3TZ symbol rate

Post by G1LPS Terry » Tue Nov 03, 2020 10:25 am

I have FWTOOL030206 is there a newer version.
Also have a copy of my config file

Update found all the manuals in my archive
Installing and changing the Configuration file and Teletext pages

if of use to anyone let me know
Last edited by G1LPS Terry on Tue Nov 03, 2020 11:23 am, edited 3 times in total.

User avatar
G1LPS Terry
Posts: 149
Joined: Mon Mar 10, 2008 10:33 pm

Re: GB3TZ symbol rate

Post by G1LPS Terry » Tue Nov 03, 2020 10:58 am

Installing and changing the Configuration file and Teletext pages

Installation :
To install the Configuration file jumper JP7 remains in the Run postion.
Furthermore you need the following files:
mimimal.txt This file has been named by Stefan minimal.txt, but can have any on4fin.txt or on4fin.conf..In here are all necessary parameters for the
You can change these parameters by opening minimal.txt in Wordpad.See "Changing the Configuration file".
teletext.o This file contains the teletext parameters.More info under "Changing the Configuration file".
textpic2.mpg This is the (non-standard)testcard.More info under "Making your own testcard".
download.bat This file contains the following instructions: fwtool -d /dev/com1 -c minimal.txt -W
If you use comport 2 you have to change this into /dev/com2
Minimal.txt can be changed and renamed.More info under"Changing the Configuration file".

Remark: These files have to stay in one directory,but you can also place all unzipped files from FWTools_Utils including Fwtool.exe in one directory.

Now click on the download.bat (or goto a DOS window and type the instructions) and you will get a DOS window showing you the following information:

D-ATV firmare tool (c) 2001-2002 Thomas Sailer HB9JNX
Then a row of startcodes,followed by
FPGA Version DVB-S 20021130233527
Writing FPGA bitstream...
Writing MPEG Encoder Firmware...
Writing configuration Area...
Checksum mismatch address 0x800000 length 10152(0x1445, 0x5382)
Writing TS Table Area...
All ok!

The text in the DOS window will look like this.It depends on the amount of new information that has to be loaded.
I prefer to go directly to the DOS window (Start-Bureau accesories-prompt)and type: fwtool -d /dev/com1 -c on4fin.txt -W.
The advantage of working directly in a DOS window is,that you immediatelly can see what happens in case something goes wrong.If you use the download.bat the window pops up,but disappears directly if something goed wrong.Things go wrong if you made eg a typing error in your config file or
a wrong testcard name etc..

Now Power off
Power on
and your configuration file has been installed.

Changing the configuration file:
To change the configuration file you can start eg with minimal.txt.Open the file in Wordpad and change the Frequency.FEC,symbol rate and Callsigns.
I work mainly with a SR = 6000 ,a FEC=3/4 and a datastream=4500k.The max Bandwidth with these parameters is abt. 8 mHz.
During a qso I can change the Frequency and the FEC by using a Terminal program like Hyperterminal.exe.You can download that from Microsoft for free.
Later on a more information abt the use of Hyperterminal.

Minimal.txt is a file with indeed minimal parameters like eg the Symbol Rate.Most digital Receivers do not work well with a SR less than 4000k.
With a SR = 4000k you have ,using QPSK,8000kb/s available for the datastream.You have to distract abt 500kb/s for system information like PID's etc.
and teletext.
I changed the SR ,the video input to S-VHS and the callsigns to mine.The picture sharpness is much better using the s-video input and setting the
"spatial filter" to sharp.In this case the video cut-off frequency is 6 mHz.Setting the video input to composite and the "spatial fillter" to sharp is not as sharp as composite video can be.The video cut-off frequency is 3 mHz and that should be around 4 mHz.(Stefan is looking after it.).You can have a look here.
If you want to experiment with these settings ,you have to change the testpicture name into testpic2.mpg.
The parameter "spatial filter" can be adjusted at soft,normal or sharp.
To install a new configuration file look at "Installation".
Do not forget comma's or destimals,otherwise the installation will not work.
Best is to give your new file another name like on4fin.txt or on4fin.conf and do not forget to change the new name in your download.bat if you intend to
use the download.bat.

Changing Teletext:
Rename the file teletext.o and teletext.c so that you still have them as a backup in case something goes wrong.
Open teletext.c with Wordpad and type your own text.A maximum of 48 characters on a line are alowed and 24 lines beneath the word pg_header.
Save the file as teletext.c and compile it into teletext.o.To do so goto the DOS window and type:
vmas -c -o teletext.o teletext.c
You will find now a new teletext.o in your directory and you can activate the file by installing your configuration file.See"Installing".
Compiling goes well in a Windows98 Se window but not in a Windows XP window.To make it possible in XP I copied a DOS 6.2 version on my FT32
partition of my Hard Disk.After clicking MSDOSSHELL all worked fine.

Using Hyperterminal.exe
With Hyperterminal (and I think with every Terminal program like eg Term.exe)you can change several parameters on the Fly.
Settings are :
baudrate 19200
comport com1 (of 2)
databits 8
Pariteit geen
stopbits 1
Datatransportbesturing geen

You have to use a "straight" rs232 cable between your Baseband print and comport.
Adjusting the frequency and/or FEC works immediatelly .After switsching off the tx and on again ,your frequency and FEC will be the original ones that are
defined by your configuration file.

Typing the letter P shows all your parameters that are loaded at startup of your tx.

not my words
copied from instructions

Post Reply

Return to “ATV Repeater Technical Topics”