every year again Sun Outage!

Turok

Hello!
hope iam right here in this section with my topic
now ever year the same,in oktober,the sun stands very deep,between the satelites,and the earth

here a calculation site

**tp://www.satellite-calculations.com/SUNcalc/SUNcalc.htm


could a lnb or dish,realy damage,in this critical moment?

maybe alumonium dishes,that reflekt the sunlight stronger,then other material?

Channel Hopper

The radiation would be unlikely to damage anything down the signal path, however the heat is another matter

The feedhorn, and/or LNB feed cap, possibly the waterproofing membranes between individual components and maybe the first few centimetres of cabling, but the damage would realistically occur in equatorial zones, on a cloudless sky and on a large dish.

There is a very fine line between "hobby" and "mental illness"

Turok

Hello!
good morning @ all!
thanx for always fast reply!

intresting whould be what the maximium temperature whould be,that a lnb,or even a dish,dipends on the material cam handle!
for e.g. in the desert +/- 50 degrees, a aluminiums dish,would reflect the sunlight and the heat so strong,that a focus point of the heat,could destroy the lnb,in a extrme case
in the past only smw manufactor get a lnb protocoll paper inside the box,and define the maximum temperature,that a lnb can tolerate,up +/- 40 degrees
when the box of the lnb is cheap plastik like today,proberbly could disforment,

so i dont live in the desert,but i could imagine that this senario could happen!
no lnb manufactur,has today measurment protokoll inside the box ,only smw,so we dont know,how big the deciance realy are,depend,on outside temprature +/- 40
does cheap lnbs realy perform bader,on hot temperatures,then the expensive ones,in todays test reports i dont read nothing about it!

when the sun shines direkt into lnb,the signal must be much lower,i wil lock exactly that time on ,my location on difrent staliltes how much,i will be the signal lost,in this critical moment!

Low Profile

I built an LNB holder for my converted meteosat dish from an old 80mm drain pipe, that deformed slightly due to (focused) heat. With proper materials any heat issue should be addressed with a commercial product. Heat (or temperature) is one of the main sources of noise, this is why some critical installations will have buried cable runs and some will cool the LNB.
I seem to recall from my college days that noise is proportional to root 4KBTR. (though it was 20 odd years ago, and I can't be bothered to google it!)

Analoguesat

Remember that the sun is moving and the heat is only concentrated onto the lnb for a few minutes. In northern Europe its not going to be a problem.

Slightly OT I followed the sun round the arc one sunny October weekend a few years back with an old dish I had lying around. It was intersting to watch the signals fade out one at a time

Analoguesat's message to the world Analogue forever!

BombedOne

Hehe yes, and what is very strange, for C band, sun was killing L polarisation, while R stays intact. I don't have any explanation for this.

trigger

We have seen some significant damage to LNB´s here in Lanzarote. Specifically with 2.7M off-set Fiberglass dishes from Poland. When I first saw one I really thought someone had got a blow torch to it. It affects these specifically due to the shiny gel coat on the dish. I think I have one of the LNB´s in the van and if so can photograph it and post on here. The plastic cover was significantly burned. The 3.1M Famaval prime focus dishes are fine because the LNB is "hidden" behind the metal feedhorn which is also like a heat sink.

Triggs

trigger

Sorry Double post