Astra 2D reception of Horizontally polarised signals.

[Terence]

I have two sky systems at my home in Alicante Spain. My first system consists of a 1.2 m offset dish connected to a Panasonic DSB20 receiver with Invercom 0.3 db LNB. This system will allow all stations to be received that are transmitted on the Astra North and South beams. The signal strength is good and I suffer little drop out, Channel 4 does drop out around 4.00 pm for around one hour in summer however.

My second sky system consists of a shared prime focus 2.4 m dish and this is connected to a Grundig 310/2 receiver with Invercom four way 0.3 db LNB. Other people sharing the dish have Panasonic DSB 30, DSB 20 and Grundig 3000 receivers.

This larger dish allows partial receipt of the Astra 2D signals. I say partial as we can receive all stations transmitted that are vertically polarised (V) but no stations that are horizontally polarised (H). The result is that we can get around 50 % of the UK transmitted channels, but can not receive BBC2, BBC3, BBC4, BBC News24, and most recently ITV news channel 525 which are transmitted on horizontally polarised channels only.

If I try and manually tune in any of the transponder numbers below, then I get a "no signal is being received display":-

10744, H 22000 5/6
10773, H 22000 5/6
10803, H 22000 5/6
10832, H 22000 5/6
10862, H 22000 5/6
10891, H 22000 5/6
10921, H 22000 5/6

Any of the vertically polarised transponders are received 24/7 and I suffer no drop out what so ever:-

10729, V 22000 5/6
10758, V 22000 5/6
10788, V 22000 5/6
10818, V 22000 5/6
10847, V 22000 5/6
10876, V 22000 5/6
10906, V 22000 5/6 (The main transponder to receive all ITV stations)
10936, V 22000 5/6

Why are there no Horizontal transponder signals being transmitted this far south, when all the vertical ones are, can anyone answer this or suggest a way that (H) transponder signals can be received.

Just to let you know that I am told that our 2.4 m dish and LNB are as good as you can get here in Spain and is working correctly. The installer stated that only (V) sgnals can be received in our area.

Is there any hardware equipment upgrade that might help

Regards: Terence

 

[jtkeep]

Hi Terence
Firstly can you recieve any H chanels on your second system from the north south beams, if you can this proves that your system can recieve H chanels and the LNB is switching from V to H (done by 13v 18v supply to the LNif not check to see if your Invercom four way 0.3 db LNB is not a type of LNB that has the four outputs as
1. Low band frequency H
2. Low band frequency V
3. High band frequency H
4. High band frequency V
if so then you will only be able to recieve the chanels you are connected to V H Low High etc.
Sometimes these non universal LNB heads are fitted as they are very sensitive.
If all this fails ask around to hear if other people in your area can recieve H.

all the best Thomas

 

[Terence]

Thomas

Can receive 100 % of Astra North and South beams transmitted as V or H polarised signals. Every one in Alicante has problems with Astra 2D H polarised signals, they are just very weak in this and many other areas of Spain to be received. I do not doute my dish installer when he stated that Astra 2D polarised signals are near inpossible to receive with a dish size smaller that 3.0 m.

Just to clear up one thing, if you are prepared to stay up until the early hours of the night, then you can recive H polarised signals for a hour or so on clear nights. The signal is not stable however and does break up, so there is a signal, but just too poor for the receiver to lock on to.

My question again is there any hardware out there that can boost, amplify or improve receiption of Astra 2D H polarised signals this far south in SUNNY Spain.

Regards: Terence

 

[Analoguesat]

Yes - a bigger dish. You can get lnb in-line amps, but they will boosts everything coming off the lnb, including the noise, and may not do anything.. However they arent too expensive so it may be worth investing a few Euros in one.

You are probably in one of those areas where there is a signal null on the H channels - strange things can happen during extreme fringe reception. The only guaranteed answer is a bigger dish.

 

[jtkeep]

Hi Terence ok that cleared a few things about H astra 2D in your area.
How long a cable do you have between your dish and reciever, if it is over 25m
you might get an improvement with a line amp, i would sugest a good quality line amp and one which has a lower gain about 10db is good as they have better signal/noise ratio.
The line amp should be placed at the dish end, this might give you 10-15% better signal quality which might be enough to get the H chanels for a longer time.

All the best Thomas

 

[Analoguesat]

There may also be an issue with Astra 2D starting to wobble very slightly. Inclination is still tiny, but for southern Spain / parts of Sweden it may be enough to tip reception over the edge.

 

[jtkeep]

Good point Analoguesat maybe the skew of the LNB could be adjusted for your location.
Also having quite a large dish 2.4 meters, the adjustment of the dish is very critical, that might give the last few % as well.
I have a friend who has a signal quality of about 25% ok for BBC but in the mornings it drops to under 20% then he loses all BBC, but over about 20% all is ok.

Good luck Thomas

 

[Terence]

Gents

Thaks for your help and yes all of us must have a cable length in excess of 25 meters from Dish to receiver. So my question now can anyone recomend a make and model number for a good quality line amp, one which has a low gain around 10db. Would especially like to hear from any one who has fitted a line amplifier and found an improvement.

Regards: Terence

 

[jtkeep]

Hi Terence I have tried on my set up i have only about 18m cable between dish and reciever, i have tried with an line amp it helped gave me about 5% more signal quality,
I have enough signal where i live so i dont use my line amp, it was a Spaun NVF 110F 10db gain, i tried with a cheap line amp it made it worse i lost about 8% signal quality.
But a good line amp works the longer the cable the better the improvement.
Here is a link it might explain better than i can i have used this company to buy stuff for my system they are highly recomended good and quick service.
http://www.satcure.co.uk/accs/page1b.htm#amps
Please let me know how you get on.

all the best Thomas

 

[billnot]

You don't say exactly whereabouts in Alicante you are, but the nul point for the horizontally polarised channels has been placed at the village of Busot.

Here, 50Km north of Busot, I lose some of them at about 1500 and others (including the BBC2 transponder) between 1900 and 2100 depending on the weather. 50Km south, in Torrevieja, they lose it a bit later with the same size dish.

I am informed by a large dish installer I trust that upping the size to 3m or even 3,6m does very little, so weak are the horizontally polarised transponders in that area.

I've tried various amplifiers; they only make the situation worse.
There does not appear to be an answer - the first person to find one will make themselves loads of money!

 

[Analoguesat]

There is an answer to this problem - but its a much bigger dish, which probably isnt practical for many folks.

If 3.6m doesnt do it, I bet a 5m would!

 

[solly]

two option is have

1-to change digibox with high quality tuner receiver

2-to change lnb invacom price forum with large dish 2.4m or more then