More BADR/Eurobird 26e

[karism]

Hello Everyone,

BADR/Eurobird 26eFringe reception continued.

With the newly acquired 3.0m , and the California LNB, normal C-band reception is all but difficult.

Now let’s see if we can stretch the laws of physics a little here.

On BADR4 26e on 11919 H 27500 the MBC channels are broadcasted.

Now the coverage goes all the way down to the DRC.

If I used the 3.0m which amplifies about 47.8Dbi ,set it very accurately, used my Gospell 55db LNB ,and boosted the signal a further 12-21Dbi.(Depending on which Inline Amp I can source) the total Dbi will be more than a 5m+ dish

You see where I am going with this.

(I might have turned into a mad scientist now with the 3m hahaha O-st )

Ideas are welcome.

Karis

 

[Analoguesat]

MBC has its own footprint which doesnt get anywhere near as far south as DRC !

Badr 4 mbc footprint

It barely touches Chad & central Sudan.....

If thats accurate you have no chance with such a tiddly dish ;)

 

[izefisherman]

If I used the 3.0m which amplifies about 47.8Dbi ,set it very accurately, used my Gospell 55db LNB ,and boosted the signal a further 12-21Dbi.(Depending on which Inline Amp I can source) the total Dbi will be more than a 5m+ dish

Karis

Only gain before the first amplifier stage and the noise figure of that amplifier contribute significantly to the overall performance of the receiving system provided that the total gain and noise figure of the succeeding amplifier stages/mixers are sufficient.

All those post-amplification criterias are pretty well met in any LNB design today so any inline amplifier past the LNB will have no improving effect unless the cable run is very lossy (long or poor cable).

Noise figures of modern LNB's are very low and terrestrial/antenna noise levels are already blanking out the full performance of these in most installations and especially if the dish elevation is lower than 20deg. (My top of the arc is 18.5 deg elevation at 21.6deg east so this is very true here)

Hence, there is NO real substitute for antenna size. Better illumination efficiency, ie. using a a cassegrain or gregorian subreflector feed can improve overall dish efficiency a little but on the other hand these are very hard to retrofit to an existing "normal" feed system so they can hardly be considered an upgrade option. So: size does matter in this game

Ize

 

[wod]

MBC has its own footprint which doesnt get anywhere near as far south as DRC !

Badr 4 mbc footprint

It barely touches Chad & central Sudan.....

If thats accurate you have no chance with such a tiddly dish ;)

well if that footprint is to be believed then how come i'm getting it on a 90cm dish in northen england, going by the footprint i would need a 2metre dish

 

[Orthoclipse]

I reckon that footprint map was drawn up by a group of lawyers rather than engineers. Possibly to avoid complications with copyrights holders for all the English language material they broadcast FTA.

 

[Lancelot]

Yep, those and the 7W footprints are known to be complete pants



L.

 

[Analoguesat]

MBC is most defintely weaker than the other tp's on Badr 4.

I can get most of the others at 45-55% quality & strength. However I cant get anything whatsoever off the MBC tp. (80cm solid dish south Scotland)

 

[karism]

Morning!
Thanks for all the input,thats one of the reasons i like this Forum.

Ok,ok.I dint have Geography at school!!

Ok,so getting any additional gain is allmost out of the question with a inline amp.

Perhaps some other transponders on BADR then?(Stronger ones?)

Have a look at Eurobird 26E Middle East Map(attached)

As you have gathered by now,this is just for fun,and experimentation.

(perhaps a little bragging right,hahaha)

 

[izefisherman]

MBC is most defintely weaker than the other tp's on Badr 4.

I can get most of the others at 45-55% quality & strength. However I cant get anything whatsoever off the MBC tp. (80cm solid dish south Scotland)

Yep, it is a steady 3dB weaker than most other Badr-4 transponders here, i need a 2.4m dish to get it. The normal Badr-4 TP's were receivable with 1.8m. Possibly they just run the MBC transponder on reduced output, who knows?

And for Nilesat 7W: I get the MBC's 24/7 with a 1.2m prime focus so the footprints are either grossly underestimated or I happen to live in a "hotspot" area. There is a big difference between the transponders though and many would need a larger dish here.

 

[karism]

Thanks for the input!
So last night i switched between my 2 Lnb`s.

no 1 :Manufacturer MTI
Model Number AC15-2CV 25k Noise Temp

No 2 :Gospell C-band 55db 17k Noise Temp

Fisically comparing the MTI to the Gospell,the Mti is allot older ,yet it looks robust.

So i put the Gospell on,and turned to 26E C-Band,The signal was aprox 17db.
I changed it out to the MTI,and it went up to 21db.

Both was propelt adjusted for FD ratio and both had the Polarity on 0 deg.

Interesting!

Likvid is suggesting that i go with a 12k Gardiner,and see how it performs.

Ps: even with the MTI,the siganl is not strong enough yet on 26e to lock.
Highest yet has been 78% Strenght ,with a signal clarity of 72%

Karis

 

[izefisherman]

So i put the Gospell on,and turned to 26E C-Band,The signal was aprox 17db.
I changed it out to the MTI,and it went up to 21db.

Both was propelt adjusted for FD ratio and both had the Polarity on 0 deg.

Interesting!

Karis

Karis, with those signal levels I assume you are measuring signal levels on the IF (LNB output). Again this is really telling you nothing about reception quality, just how much total gain the LNB has which isn't the same at all. You need to measure carrier to noise (C/N) or signal to noise (S/N) in order to determine if you have a good enough reception quality. If the C/N was 17dB it would be more than enough for reception at any FEC value. For 3/4 FEC the threshold value is in the order of 6dB C/N.

 

[karism]

Hmmm,very interesting!

I`am guessing that i cant do it with my little meter? Darn,it allready cost a hell of alot of money.

See,everyday i learn something new!

Thanks for helping so much everyone!

Karis

 

[izefisherman]

Karism, what is that "little meter" you are talking about?

A so called satfinder that you put inline in the LNB to receiver cable run or something more elaborate?

 

[karism]

I can find a pic on the Net of it.
I`ll have to go a take a pic of it this afternoon.

It fits inline after the Lnb,and before the STB,it doesnt require the STB though,can work on its own with the LNb as well.

Karis

 

[izefisherman]

Ok, I am just curious if it measures absolute signal level only or if it can measure C/N as well.

 

[karism]

Sorry for waiting so long for the pic!


Karis

 

[EMPB]

well if that footprint is to be believed then how come i'm getting it on a 90cm dish in northen england, going by the footprint i would need a 2metre dish

I don't believe that footprint either. Watching Buffy on Action right now - NW England (Blackpool) 95cm dish 0.3db LNB, Topfield TF4000 PVR.

Yes def not as strong as other transponders e.g. Dubai One on 12.130V 27.5.

Anyone getting 7W in the UK? Id always believed those naughty footprints.

 

[karism]

Ok,here we go for round number 3.

So,MBC`s transponders are not the best to try and chase.

So lets look at it from a technical point of view.

Which Transponder should i be looking it??

What type Ku LNB should i use/consider looking at??

I think it will help to add the 12-20db inline amp after the Ku Lnb.The c-band,and other Lnb`s i`ll leave unamplified,otherwise i will require a attenuator for the stronger local footprints.