Advice Needed Dual feed: 5W (main focus) + 13E - 90cm Triax dish

[Lazarus]

Well clearly something is wrong as you are within the 48dBW contour so a 120cm dish is massive overkill (Assuming it's aligned to 5W and not elsewhere ie part of a multi-LNB system).

You should have enough rain-margin to stave off even extreme weather: So much margin that a deaf receiver shouldn't present a problem either.

Although I've never experienced it myself, despite occasionally using a 1.1m on 28E, there are occasionally reports of overloading causing problems. Indeed, I believe such an issue is mentioned on the Costa Blanca 2E/2F Thread

 

[Channel Hopper]

Well clearly something is wrong as you are within the 48dBW contour so a 120cm dish is massive overkill (Assuming it's aligned to 5W and not elsewhere ie part of a multi-LNB system).

You should have enough rain-margin to stave off even extreme weather: So much margin that a deaf receiver shouldn't present a problem either.

Although I've never experienced it myself, despite occasionally using a 1.1m on 28E, there are occasionally reports of overloading causing problems. Indeed, I believe such an issue is mentioned on the Costa Blanca 2E/2F Thread

The problem is not with power, but the skew of the LNB on the dish. 5west is somewhat out of the ordinary and you will have to quite accurate with the LNB alignment.

 

[Lazarus]

In what way out of the ordinary?

I happily used a Sky LNB on a minidish for 5W: The skew was clearly miles out. Reception was perfect on all frequencies and both polarities.

In this case, Member Hughes is using a proper dish and fully adjustable LNB, so at least has the capability of adjusting it correctly. In NW Spain, skew will be only a few degrees from zero, surely?

 

[Hughes]

This weekend, weather and time ( the same word in Spanish, and French!) permitting, I'll try a smaller dish as well as playing with the skew yet again. I can see myself lugging the old 30 inch CRT TV out into the garden again! I was wondering if the FEC or some other method is being employed to make reception difficult in all but the centre of the footprint... The dish is pointing hopefully at 5 degrees West only, and not receiving 8W at the same time.

 

[sonnetpete]

Does seems strange...I just scanned 5W using my 1.2M and all transponders are around the 14dB to 12dB range. The Berbere channels are showing 12.2dB. I agree, 1.2M is overkill on 5W even with the LNB grossly out....

 

[Lazarus]

Everyone needs an excuse to tinker!

 

[Hughes]

Everyone needs a decent satellite meter me thinks!

 

[Hughes]

I've just checked the FEC ratios on 5W on Lyngsat. The FTA channels such as France 2 are 2/3, whereas Fransat SD channels are 7/8 and HD are 8/9. Could this be part of the problem, perhaps trying to stop reception in North Africa? Please remember I'm a linguist, not a radio technician!

 

[Lazarus]

I very much doubt it.

You should be getting similar results to myself and Sonnetpete.

 

[Hughes]

I've just had a look at the footprint map for 5W on Lyngsat, and my location is indeed within the main coverage area, albeit near the edge, and reception appears to tail off dramatically to the West. But I wonder if the map is over-simplified. For example, why can't I receive any of the Italian channels? How about in Normandy and Yorkshire? Maybe the different beams are directional, not covering the whole footprint, and FECs of 7/8 and 8/9 only serve to make the signal more fragile. The signal quality on 11554V shows 75 on the Skybox F3, but freezes on the Fransat HD box whose name is VirtuoZ. Obviously further tinkering is required!

 

[Channel Hopper]

In what way out of the ordinary?

I happily used a Sky LNB on a minidish for 5W: The skew was clearly miles out. Reception was perfect on all frequencies and both polarities.

In this case, Member Hughes is using a proper dish and fully adjustable LNB, so at least has the capability of adjusting it correctly. In NW Spain, skew will be only a few degrees from zero, surely?

y u no rissen

http://www.satlex.be/fr/azel_calc-p...2&lo=-0.5&country_code=us&diam_w=75&diam_h=80

 

[Lazarus]

I've just had a look at the footprint map for 5W on Lyngsat, and my location is indeed within the main coverage area, albeit near the edge, and reception appears to tail off dramatically to the West. But I wonder if the map is over-simplified. For example, why can't I receive any of the Italian channels? How about in Normandy and Yorkshire? Maybe the different beams are directional, not covering the whole footprint, and FECs of 7/8 and 8/9 only serve to make the signal more fragile. The signal quality on 11554V shows 75 on the Skybox F3, but freezes on the Fransat HD box whose name is VirtuoZ. Obviously further tinkering is required!

The TPs bearing the ACM Streams for Italian Channels simply don't register because our boxes don't have the capability to recognise them. They are related to Italy's DTT network and require special equipment to decode.

My F3 shows Quality 76 on TMC (11554), similar to yours. I've never seen the F3 register a higher reading so that seems to be maxed out, in effect)

Does the Post immediately above help you with skew?

 

[sonnetpete]

Looking at that Satlex site, for Galicia the LNB for 5W should be almost vertical. I can only think of two possible answers : either the dish azimuth is off or that particular receiver is very 'deaf'....

 

[Hughes]

First of all, thanks for all the help so far! My plan is to go outside with TV and Metronic Fransat SD box, as both have Scarts, and try a smaller dish just in case there is some form of overload. As regards skew, I may make mistakes, but I've been twisting LNBs for 25 years. My
first success was getting rid of the sparklies on UK Gold on a professionally installed system here in Lugo back in the old days, and I keep my hand in trying to wring as much signal as possible out of 28E.

 

[Hughes]

Another mystery solved. As you all predicted the problem was at the Earth station and not the satellite! On Thursday I googled in French Fransat reception in Portugal, and then in Morocco. It soon became clear that there is indeed a strong signal this far west. So this morning I re-aligned my 60cm dish from 19E to 5W, using a sat beeper meter. This gave a very healthy scream, suggesting good signal strength. I then unscrewed the cable from the 120cm dish, connected it to the quad LNB on the small dish, went inside, and had perfect reception on the FTA channels. It was then the turn of the second feed, which goes direct to to a Fransat box. I unscrewed the F connector, and pulled the cable free through the undergrowth which forms part of the Hughes "garden" only to find a nasty kink, then a cut almost right through , and when I had chopped off the bad bits found that the whole cable had its copper foil oxidized muddy brown, and damp. I cut off a few more metres, still damp and discoloured, but I connected up anyway to another port on the LNB, and the Metronic Fransat SD box immediately updated itself and for the first time ever asked me which France 3 region I would like to make my own. I chose France 3 Montpellier! All the encrypted SD channels now work perfectly, as do the radio stations at last. They are on high frequencies and were perhaps most affected by the poor cable.
So a successful outcome, without having to take TV into garden. And the 120cm dish is now free for more fun, maybe I'll have a go at 7W!
We've been at our present address for 15 years, so some of the cables are pretty old and have suffered many years of heat, cold and rain, and were never installed very well in the first place!

 

[Lazarus]

That's splendid: Had to be something simple ;)

 

[andrea89]

Not sure what you mean by 30 degrees either side of central as that would cover 60 degrees of arc. You are looking to cover 18 degrees (5W to 13E) Look at the picture of my Triax TD88. It covers from 42E on the extreme left to 19E on the right, a spread of 23 degrees. What you are trying for is pretty doable...
View attachment 67879

do you get a strong signal even during rain and/or snow ?
Your dish is exactly like mine.

 

[sonnetpete]

It gets a strong signal just either side of centre, yes. Obviously it suffers in rain/snow but has a fair margin for fade under those conditions. Personally, the main problem I've found in trying to use the TD88 for multi sat is if you use the Triax bracket. this isn't easy to angle if you want to get a wider spread of the arc and has no facility to mount an LNB at focus. You can achieve better results with it if you are prepared to 'modify' it. You may notice I'm using a universal bracket on it at the moment but this is poorly engineered and I'm going to replace it with something better next year. I'm lucky that the TD88 is mounted at just above head height so tinkering with it is relatively easy.

 

[hexah]

It's possible to bodge the Triax bracket by mounting an LNB in the normal holder and using the Triax bracket upside down, clipped on to that LNB. It works but it can slide around of its own accord on some LNBs due slick plastic. Some tape may help.

Which proves it is a daft bracket design!

Gibertini is much better.

 

[hexah]

I unscrewed the F connector

Did you use self amalgamating tape?

and pulled the cable free through the undergrowth which forms part of the Hughes "garden" only to find a nasty kink, then a cut almost right through , and when I had chopped off the bad bits found that the whole cable had its copper foil oxidized muddy brown, and damp.

Its amazing how quickly capiliary action can drag in moisture. Sounds like rerouting is needed to keep it in a place off the ground where it can drip dry and stay dry.

I cut off a few more metres, still damp and discoloured, but I connected up anyway to another port on the LNB, and the Metronic Fransat SD box immediately updated itself and for the first time ever asked me which France 3 region I would like to make my own. I chose France 3 Montpellier! All the encrypted SD channels now work perfectly, as do the radio stations at last. They are on high frequencies and were perhaps most affected by the poor cable.
So a successful outcome, without having to take TV into garden. And the 120cm dish is now free for more fun, maybe I'll have a go at 7W!
We've been at our present address for 15 years, so some of the cables are pretty old and have suffered many years of heat, cold and rain, and were never installed very well in the first place!

Webro WF100 is really cheap now in the UK, I don't know about Spain. Maybe airlines will allow 50m or 100m reels in the luggage if they inspect it first as it would look wierd on the xray.