Astra 2E: Iberia & Balearics Reports

[Archive4]

Just had a major drop in signal in my area at 21:05 approx, had reception problems on a few ch´s, esp ITV on 10891, back now but weaker than normal. We do have low clouds and light riain, but this is the first time I have noticed this since 2E went on line. (Had to happen when SWMBO was watching Emmerdale!)

 

[Huevos]

No, this is signal lower under clear skies. Did have a bit of rain earlier though (around 8pm) and lost every transponder on the 1.1m dish.

 

[altman]

Huevos can you tell me the signal on 12640H? so that I can compare with my system
I going nuts with this, I get 12db on that transponder, and 6.3 on 10906 on my 1.25m PF with the very old 2nd hand 0.7db offset Televes LNBF
every feedhorn/LNB combination/adjustment is worse, and I even tried a IBU converted to c120
the same IBU, before conversion on a 60cm dish gave me 10.5db on 12640H and was the best LNB I have (and I have a few dozens of them)

so, as the 1.25m is roughly twice as big, 6db more gain than the 60cm should be expected no?

 

[hvdh]

You meant 12640V ?

 

[altman]

he checks his TP list... its all wrong and outdated:mad:
please excuse me as I go bang my head against the wall for a minute

 

[altman]

much better now, the list, head still hurts a bit ;)
12110H 16db (2A south)
11307V 10db (e28 super)
12480v 6.5db (north beam)
10906v 6.3db (uk spot)

 

[Tururu]

......I going nuts with this, I get 12db on that transponder, and 6.3 on 10906 on my 1.25m PF with the very old 2nd hand 0.7db offset Televes LNBF every feedhorn/LNB combination/adjustment is worse, and I even tried a IBU converted to c120 the same IBU, before conversion on a 60cm dish gave me 10.5db on 12640H and was the best LNB I have (and I have a few dozens of them)

so, as the 1.25m is roughly twice as big, 6db more gain than the 60cm should be expected no?

Los LNB 0.7 dB Televes PF, no se la calidad, pero los LNB para antenas offset, malos malos.
------------
The LNB 0.7 dB Televes PF, not the quality, but the LNB offset antennas, bad bad.
125cm PF = 110cm offset +.
Por las perdidas de sombra del LNB y soportes sobre la antena.
--------
For the lost shadow LNB and brackets on the antenna.

Levels in Madrid now.
With 94cm dish (98x90cm = 0'692m²) from Madrid. (11:35 GMT) clear general.
12110H 18.0db (2A south)
11307V 10.5db (e28 super)
12480v 7.0db (north beam)
10906v 10.5db (uk spot)

PD: LNB Inverto Black Ultra 0.2dB.

 

[altman]

thank you for the readings

this lnb is offset, a really old one, I think it works because the FD of the dish is 0.43 and Televes offsets were 0.5 instead of the more common 0.6~7
it has also been cherry picked, I have 6 more of the same model, all bad performers on 60cm televes offset, average on the PF.

yesterday I've modified an old MTI c120 0,7db I had around with new 0.35db transistors, in the next few days I'll take this old dish off the roof and put it in a stand on the garden so I can finally test the MTI and the IBU Ive also modified (2db more gain and c120)

BTW, I disagree with the size comparisons but that is for another topic ;)

 

[Pedro0102]

Just ordered the Swedish Microwave XM-140 feedhorn to experiment with my 3.1m Famaval.
It is the only feedhorn I could find on the market with an F/D of 0.30. Let's see how it will perform...

Finally had a chance to install the new XM-140 Swedish Microwave Feedhorn with my 3.1m antenna...
And quite disappointing... 100€ and 2 dB lost.
Back using the Invacom Feedhorn!

 

[altman]

Have you ringed Famaval so that they can advise on the correct feedhorn for their antenna?
they make one for 0.41
http://www.famaval.pt/pt/contactos.html
I think I have two old feedhorns that might work there, send me a PM with your location in Lisbon, I go there from time to time.

 

[hexah]

Finally had a chance to install the new XM-140 Swedish Microwave Feedhorn with my 3.1m antenna...
And quite disappointing... 100€ and 2 dB lost.
Back using the Invacom Feedhorn!

Were Famaval talking out of their backside about the f/d?


2 dB is only 1 dB from 3 dB . . .

 

[joddle]

Shifting the topic a bit - last night my trusty old Humax Foxsat HD failed for the second time - last time it was repaired with change of capacitors in the power supply - and maybe they have gone again ! - same symptoms BUT before I do that, what are people these days recommending out here on the fringe in Spain for freesat reception - but not interested in a Linux box - just a good freesat HD box. My little Manhatten (only £49 at Curries) is working OK but is not very sensitive and so I really want something at least as good as the Humax as anyway the Manhatten is the kid's box and they want it back!

 

[dmaavrigdo]

Shifting the topic a bit - last night my trusty old Humax Foxsat HD failed for the second time - last time it was repaired with change of capacitors in the power supply - and maybe they have gone again ! - same symptoms BUT before I do that, what are peole these days recommending out here on the fringe in Spain for freesat reception - but not interested in a Linux box - just a good freesat HD box. My little Manhatten (only £49 at Curries) is working OK but is not very sensitive and so I really want something at least as good as the Humax as anyway the Manhatten is the kid's box and they want it back!

In my fringe location the Technomate F3/5 is much better than my foxsat was.

 

[Huevos]

My finding is modern Humax STBs are nowhere near as sensitive as the earlier Humax. And the Manhattan... well... I decided not to carry those. I like the Goodmans SD box. But anyway in South Valencia with a 2.4m dish any piece of rubbish will work.

Problem with Freesat boxes is there is no freedom to mix regions which means you end up with either a weak ITV1 transponder or weak BBC1. And BBC2 England transponder is very weak. So personally, (especially south Costa Blanca) I wouldn't get involved with Freesat boxes. Which means if you want a proper 7 day EPG your only option is a ************.

 

[altman]

Were Famaval talking out of their backside about the f/d?


2 dB is only 1 dB from 3 dB . . .

not really, just think about it, 2.3m has 0.41 F/D, to make a 3.1 you just bolt the petals, by extending the parabola, the F/D must decrease
until a matched feedhorn is used, the dish behaves as a 2.3m with a shield against edge noise, no more gain, or marginal at best

its the same problem I'm having with my 1.25m 0.43F/D, I have a 0.5~6F/D feedhorn, so I'm just illuminating 70cm of those 1.25m

 

[FRINGE]

Shifting the topic a bit - last night my trusty old Humax Foxsat HD failed for the second time - last time it was repaired with change of capacitors in the power supply - and maybe they have gone again ! - same symptoms BUT before I do that, what are people these days recommending out here on the fringe in Spain for freesat reception - but not interested in a Linux box - just a good freesat HD box. My little Manhatten (only £49 at Curries) is working OK but is not very sensitive and so I really want something at least as good as the Humax as anyway the Manhatten is the kid's box and they want it back!

I agree with dmaavrigdo. I have a Humax but recently got a TM F3/5 and the reception is a tad better. I made a post here: http://www.satellites.co.uk/forums/...ries-africa-reports.159946/page-9#post-879330

 

[hexah]

not really, just think about it, 2.3m has 0.41 F/D, to make a 3.1 you just bolt the petals, by extending the parabola, the F/D must decrease
until a matched feedhorn is used, the dish behaves as a 2.3m with a shield against edge noise, no more gain, or marginal at best

its the same problem I'm having with my 1.25m 0.43F/D, I have a 0.5~6F/D feedhorn, so I'm just illuminating 70cm of those 1.25m

Having looked at the Favamal catalogue all their PF have standardized on f/d 0.41 including their 230 which can be petalized to make a 310 (though it doesn't have a great reputation, being difficult to get true, a solid 310 is always preferred followed by a two piece).

Most manufacturers have done the same thing because it makes sense to manufacture and stock only one universal feedhorn for their range of dishes. In the olden days there was a lot more variation of f/d and I have several feedhorns.

Contact Favamal and see what they say. Longer arms would put the 0.41 feed horn in focus but adjusting the feedhorn using the screw should allow for a shallower focus and have the same effect possibly with slightly more rejection of noise which is desirable with a bigger dish as background noise will increase, particularly in urban areas.

 

[Pedro0102]

not really, just think about it, 2.3m has 0.41 F/D, to make a 3.1 you just bolt the petals, by extending the parabola, the F/D must decrease
until a matched feedhorn is used, the dish behaves as a 2.3m with a shield against edge noise, no more gain, or marginal at best

its the same problem I'm having with my 1.25m 0.43F/D, I have a 0.5~6F/D feedhorn, so I'm just illuminating 70cm of those 1.25m

Having looked at the Favamal catalogue all their PF have standardized on f/d 0.41 including their 230 which can be petalized to make a 310 (though it doesn't have a great reputation, being difficult to get true, a solid 310 is always preferred followed by a two piece).

Most manufacturers have done the same thing because it makes sense to manufacture and stock only one universal feedhorn for their range of dishes. In the olden days there was a lot more variation of f/d and I have several feedhorns.

Contact Favamal and see what they say. Longer arms would put the 0.41 feed horn in focus but adjusting the feedhorn using the screw should allow for a shallower focus and have the same effect possibly with slightly more rejection of noise which is desirable with a bigger dish as background noise will increase, particularly in urban areas.

Installing the petals does not change the focal distance. The parabola is the same, thus the focal point is unchanged.
What varies is the F/D ratio. With petals on the F/D decreases to 0.3.
However, there are not many feedhorns on the market for such low F/D values. The adjustable invacom just goes down to 0.31 and I though I could get a bit more out of the antenna if I could get a matching feedhorn.
The Swedish Microwave XM-140 indicates in the specs an F/D ratio of 0.30 but I lost aprox. 2dB comparing with the Invacom.
I've read on other threads about a "cyprus" feedhorn. But I believe this was an custom made feedhorn for the cyprus and no longer available. If it is I don't know where to buy it!

 

[Huevos]

I've read on other threads about a "cyprus" feedhorn. But I believe this was an custom made feedhorn for the cyprus and no longer available. If it is I don't know where to buy it!

I've got one of those on the shelf, and that's where it is going to stay. I've tried that on a 2.4 and a 3.1m dish and performance is crap. And like I keep saying the best performing feedhorn in this part of the band is the Famaval.

 

[hexah]

I've got one of those on the shelf, and that's where it is going to stay. I've tried that on a 2.4 and a 3.1m dish and performance is crap.

The 'cyprus' Frankenstein feedhorn was made for some specific instance so its probably not relevant to much else anyway.

And like I keep saying the best performing feedhorn in this part of the band is the Famaval.

As I said it was a free for all in the early days of satellite.

Now manufacturers have seen the advantages of standardization, modularization and reducing parts to the minimum inventory possible. The engineers in Famaval have all the advantages of modern CAD CAM and quality control. Designing an effective standard feedhorn for their dishes was probably the easiest thing they did since leaving university.

So Huevos is right, as usual.