DVB-S2 Signal Finding

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womble
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DVB-S2 Signal Finding

Post by womble » Wed Sep 10, 2008 1:12 am

This is a rough guide to finding DVB-S2 signals.

You *really* are much better waiting for a true blind scanning DVB-S2 receiver to become available.

You will need the following equipment:
  • Spectrum Analyzer
    DVB-S Blind Scanner
    PC DVB-S2 compatible card with DVBViewer software
    TransEdit tool available from members section of DVBViewer website
    Calculator
    Pen and Paper
    Lots of Patience
For the purpose of this guide I will use the Satellite Spectrum Analyzer plugin with the Triple Dragon satellite receiver and a Manhattan XT-F satellite receiver for blind scanning DVB-S signals.

You can do the first two steps whichever way round you like, you just need to compare the results as in Step Three.


Step One

Blind scan the desired satellite between the range normally used for feeds using the DVB-S blind scanning receiver.

In this this case our satellite is Eurobird 4 which sits at 4 degrees east, and the feed range between 10950 to 11200 horizontal band only.

Note down all the results.

So for my example, the receiver found no signals.
Not the best for an example, in most cases you would pick up a few signals.

If the blind scan range is increased to 11300 then found one signal at 11229 h 23148 3/4


Step Two

Look at the satellite through the Spectrum Anazlyer and note down the signal peaks for the feed range.

See the image below for an example.

The higher the peak the stronger the signal.

Image

Before someone moans the actual colour scheme is different on the television image, the method I use for capturing the image messes it up.

Very quick guide to the controls.

Use the Outdoor unit button to change everything to the desired settings.

PWR: 13V for vertical polarization, 17V for horizontal polarization.
22kHZ: off is low band, 10700 to 11900 and on is high band, 11550 to 12750.

These are true for your bog standard Ku Band Universal LNB.

IF: this is the frequency from the LNB, you need to add a value to this for the end frequency to tune the receiver with.
Low band (22kHZ off) then add 9750 to the IF value.
High band (22kHZ on) then add 10600 to the IF value.

So for the image, call it IF 1305 plus 9750 gives us a frequency to tune of 11055

According to our spectrum analyzer plot, there are the following peaks.

10960
11056
11137
11183
11229
11422
11766 then a few smaller peaks in a row
We only need worry about the range from 10950 to 11200, so that cuts it down a bit.

Now cross reference the DVB-S blind scan results against the peaks.
In this case no results were found so we have some unidentified signals :)
Namely, 10960, 11056, 11137 and 11183

From past experience I know that the peaks at 10960,11137 and 11183 are nothing.
So that leaves us with a large unidentified signal at 11055 :)


Step Three

We have a possible signal so we will scan this in DVB-S2 using some common symbol rates to see if we get lucky.

For this I use the TransEdit tool, you could maybe use other DVB Software but this is my preferred method.

Start TransEdit, pick the desired satellite from the Transponder List File window on the left, in this case 4e.

Image

Now on the right hand window near the bottom press Blind Scan button.

Fill out the Parameter Ranges on the Blind Scan dialog as follows.

Frequencies: 11055
Symbolrates: 7200,14400,20000,20926,26666,27745,27500,28800
Polarisations: 0
Modulations: 0
Pilot Symbols: 0
FEC Values: 0
DVB-S/DVB-S2: 1
Roll-Off Values: 0

Image

Press Apply then Scan and the Scanner window should open.


It will now scan our target signal going through the symbol rates listed and hopefully find something.

Bingo :)

Image


Notes

The method described here relies on a couple of things.
Firstly, that you can identify the signal peaks from the spectrum, when multiple feeds are in close proximity then it is not so easy.
Secondly, the feed is using a common symbol rate.


If the above steps did not find any results then you can either give the signal up as background noise, or go back to the Blind Scan dialog and try different symbol rates.

Tip, if you enter 10000-20000:40 then it will scan 10000 to 20000 in steps of 40

Be warned though this can be very time consuming and often give no results.
Also check that the signal is still there from time to time otherwise you will be scanning for nothing.

Good luck and Happy Hunting.

womble



This guide was written for the following sites.
http://groups.google.com/group/feedhunter
http://www.sat-benelux.nl/

2008-09-09 @ 23:34
Last edited by womble on Tue Apr 13, 2010 11:19 pm, edited 1 time in total.
Triple Dragon, Dreambox 500 and a potato peeler which works better than CIFS sharing.

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stanley_cassidy
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Re: DVB-S2 Signal Finding

Post by stanley_cassidy » Wed Sep 10, 2008 1:35 am

Good work and interesting guide ;)
Yes,it's true: you need for this format a lot, a lot, a lot of patience and a very lot,a very lot and a very lot time ...
frangar non deflectar

EnoSat
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Re: DVB-S2 Signal Finding

Post by EnoSat » Wed Sep 10, 2008 10:35 pm

yes , i am too use this metod
but my satfinder = NOKIA9600 + DVBedit or ScanEdit

Image
etc. signal scan from Intelsat706 50East before start Olympics Games

in PC use TT S2-3200 pci-dvb card

Spc
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Re: DVB-S2 Signal Finding

Post by Spc » Mon Apr 12, 2010 5:30 am

Interesting guide.
Thanks.

I shall try it.

feedster786
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Re: DVB-S2 Signal Finding

Post by feedster786 » Mon Aug 23, 2010 11:18 pm

wow that's interesting, admittably i have collected a lot of frequencies over the years, and just go through them one by one.

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