Newbie Here Boosting Satellite Signal

[ChrisThomas]

Hi. Firstly, apologies if this has been covered before. I have looked.

I spend some of my time the a flat in the French Alps where I have access to both UK Freesat and French TNT (Freeview equivalent). On the roof of the apartment block I assume there is a single satellite dish and a single digital terrestial aerial. The signals from both arrive in the flat via a single coax socket. A 4m cable runs to a Seada, "Decoupler", which splits the signals into a Humax Freesat box and a Humax Freeview box. The Freesat box is connected to the TV via HDMI and the Freeview box via coax and SCART. In general the system works very well.

The exception to the rule is during bad weather (typical low pressure, wet etc. but not necessarily windy). Then some Freesat channels give, "No or bad signal", others loose sound and/or become very pixelated. The TNT (Freeview) reception is not affected.

My assumption is that the Freesat signal is weak - mainly due to the length of cabling which is inevitable in a large apartment block. I see that satellite signal boosters are available. I appreciate that these should be fitted close to the dish end of the system but that's not possible in my case. I could fit one within my flat though. Potentially it could go between the wall socket and the, "Decoupleur": in which case I assume the TNT (Freeview) signal would also be boosted (unnecessarily and potentially with a negative effect). Or it could go further downstream between the, "Decoupleur", and the Freesat box.

I wonder if, in my system, there is power to drive a simple inline booster or if I need an externally powered one? Are these boosters intelligent enough to boost the satellite signal without over-boosting the terrestrial signal? And there are probably lots of other factors I haven't considered!

I can just buy one of the many satellite boosters available and try it but any advice would be welcomed.

Thanks in anticipation.

Chris

 

[Analoguesat]

Boosters amplify the noise as well as the signal, and often perform poorly.

I have my doubts it would do much because the basic problem is that the dish isnt big enough - the satellite signals are being absorbed by the rain and the lack of signal is pushing the signal "over the digital cliff"

 

[PaulR]

First, congratulations on being in a flat where the satellite dish isn't pointed at 19E. It must be a special arrangement for the Brits in the rest of the block. Possibly it's multi-satellite and another (or even more) satellite is available using what is called a DiSeqc switching signal for the non-Brit inhabitants.

Anyway, back to the plot. A signal booster is highly unlikely to help. As you say, in the rare cases that it can help it needs to be close to the satellite dish. Very occasionally a booster close to the receiver can help for unknown reasons so, if you have one handy, you could try it out.

If all the apartments have this facility then it's likely that the satellite dish and terrestrial aerial feed what is known as a multiswitch. This means that there isn't a direct connection from the dish to your apartment. So, a better LNB, a replacement multiswitch and/or new cabling might be a better bet. If you can get to this multiswitch then putting the booster up there would be a better bet than downstairs.

Finally, you haven't said what size this satellite dish is or, assuming it's a multi-satellite set-up, whether the LNB is at the primary position. It's highly likely that what's really needed is a larger dish.

 

[archive10]

Chiming in on what AS and PaulR says: Don't waste your money on a signal boosteur.
It is almost certain you need a bigger dish.
Also possible, but less yielding is a better aligned dish (including skew), but this will only give small improvements compared to a bigger dish.
I've used at 60cm dish with luck in the Haute Savoie, so a decent 80 or 100 cm should give you good signal.

However, if you have no say in the choice of kit used (or the alignment of said kit), you probably have to live with the conditions as is.

Just for satisfying our curiosity, It would be very interesting if you obtained access to the roof (assuming it's flat), and could snap a few pics of the dish and LNBs...
(I have myself swapped dishes on roofs from 80 to 100 cm without anyone noticing except for meeee...!)

 

[william-1]

Boosters also block out some signals found this out the hard way so I got a bigger dish & binned the booster.

 

[ChrisThomas]

Thanks, all, for the prompt help.

I don't have access to the roof or cabling beyond my flat so it seems there's little I can do in the short term. I may see whether I can persuade the Syndic to install a bigger dish but, to be honest, the problem only occurs in particularly poor weather so it's no big deal.

In response to PaulR, and just to complete the picture, there are actually three satellite dishes on the roof (one for each of French, Italian and UK satellites if I recall rightly) and each owner declares which one they want to be connected to.

If there's a remote chance a booster at my end might help for some inexplicable reason I might as well get one to try. They seem very cheap - any suggestions of which one to go for?

Thanks,

Chris

 

[archive10]

My friend, I am 99% sure there is no booster that will help you get better reception when it rains.
And this is not 100% purely because your setup may have some freak condition.

But, you have to understand that it is NOT the absolute signal strength that is the prime challenge here; it is the difference between signal and noise.
When it rains (or snows or whatever fom of precipitation you choose), the water in the atmosphere absorbs the microwaves, and thereby removes your signal.
So the signal to noise ration goes down. Noise does not, as this stems from background radiation, electronic heat, and other local soures.
(The satellite signal being NOT a local source).
The only, and I repeat, ONLY way this can be improvd is to start with more signal to noise ratio.
And the signal-to-noise can ONLY be improved with a larger dish.

You also have to understand that your receiver contains an automatic gain cicuit, that will boost the signal as needed.
No need for more boosting - it is pointless to add more electronics.

I know you intensely want to deploy a signal amplifier just in case it might work (and we all might be wrong).
But please save the money (and the time spent fiddling with cables) - it won't make nay difference.
(In fact it may just make it worse - the added electronics just make more noise...)

 

[archive10]

Thanks, all, for the prompt help.
In response to PaulR, and just to complete the picture, there are actually three satellite dishes on the roof (one for each of French, Italian and UK satellites if I recall rightly) and each owner declares which one they want to be connected to.

Now here's where you can make a difference:
Tell the syndic that you can change the 28.2E dish free-of-charge (you will have to swallow the cost), and put ina larger dish. The LNB stays the same, the cabling stays the same, no-one except the brits will notice, and the syndicate will have an even more attractive offer to make to the next ex-pat tennant!!

 

[MarkW]

Thanks, all, for the prompt help.

I don't have access to the roof or cabling beyond my flat so it seems there's little I can do in the short term. I may see whether I can persuade the Syndic to install a bigger dish but, to be honest, the problem only occurs in particularly poor weather so it's no big deal.

In response to PaulR, and just to complete the picture, there are actually three satellite dishes on the roof (one for each of French, Italian and UK satellites if I recall rightly) and each owner declares which one they want to be connected to.

If there's a remote chance a booster at my end might help for some inexplicable reason I might as well get one to try. They seem very cheap - any suggestions of which one to go for?

Thanks,

Chris

I assume others watching the UK dish are experiencing the same problem?I got a booster,in desperation,and it made no difference.

 

[timo_w2s]

I too tried a booster just in case the 1% chance helped me, but of course it only made things worse.

 

[ChrisThomas]

Thanks, all. I think I get the message regarding boosters and what really needs doing!

Chris

 

[Analoguesat]

Unfortunately there is absolutely no substitute for more metal collecting more signal.

 

[Analoguesat]

If you do get a bigger dish installed make sure you find an installer who knows what he is doing with big dishes for Brit installs & not some cowboy who only knows about 5W & 19E for the Froggie stuff!

 

[skomedal]

And remember offset dish width is real size not height

Regards

 

[a33]

Bigger dish obviously is the best solution.

What might also help a little bit: Some LNBs are very rain-sensitive. Some plastic coverage over/above the LNB could be used, so that less rain-drops are falling on the LNB-head.
There is a commercial product called the paraprot, for a series of LNBs (multifeed).
But some make a raincover out of a plastic bottle , which sticks out in front of a single LNB. Works just as well.
I believe in skandinavia they even sell bottle-like rainprotectors, which you tie around your LNB-head.

If you only have problems with bad weather, such a solution might be good enough.

Greetz,
A33

 

[Terryl]

The only "L" band* signal boosters that really work are used in professional installations, and they can cost up to several thousand.(depending on the local currency)

The LNB in use may be old, and has gone a bit sour in the noise floor, a new LNB would/could be the first step,(if you can't replace the dish) you may lower your noise floor a few tenths of a dB, but in the long run a bigger dish would improve the performance.


* "L" band, the satellite LNB's IF output signal, usually from 900 to 2500 MHz.

 

[rolfw]

I think this is a Ku band installation Terry.

 

[PaulR]

Yes but what Terry means is that the signal been frequency shifted downwards towards the L band for transmission down the cable to the receiver. And it is this block of frequencies that is being amplified.

 

[Terryl]

I think this is a Ku band installation Terry.

Ku band transponders are in the 10.7 to 12.7 GHz band, you take the TP frequency and deduct the LO (Local Oscillator) frequency of the LNB (11250, 10750, 10600 or what ever it is) to get the "L" band frequency (or IF frequency) this is what gets sent down the standard RG-6 coax to your satellite receiver.

Example:
TP frequency = 11875 MHz, minus the LNB LO of lets say 10600 MHz, give us an IF frequency ("L" band) of 1275 MHz, well within the RG-6 coax spec's.

The standard consumer grade amp for a satellite can only amplify this "L" band or IF frequency, it does nothing for the actual 10.7 to 12.7 GHz frequency coming down from the satellite.

So if your signal from the LNB is a weak one due to the input signal being on the weak side, all it will do is bury it in noise.

In broadcasting we use to take the actual down link frequency of the transponders and run them into a 3 to 5 GHz amp far superior to the ones in the standard consumer grade LNB's, then into a very high quality down converter, then into the engineering space for demodulating. (we use to, this was a long time ago, we found it was cheaper to go with 30 to 40 foot dishes on the "C" band satellites*)

*CATV company's here stateside use "C" band satellites for their programming, "C" band is far less prone to rain or snow fade, and with a 30 foot dish we don't loose signals to weather fade outs.



OOppps sorry I'm starting to ramble on, too much coffee this morning...............................Sorry my fault....

 

[rolfw]

Ah yes, sorry, wasn't thinking.

Having said that I have used inline amps on very long cable runs with great success, providing the signal to noise ratio is good at the dish, I've inserted them in the middle of 150m cable runs, before fibre was an option.