Glare causing loss of signal

[iamnomad]

I wrote in some time ago about my signal disappearing on my 10 foot dish when the sun was really shinning. The signal would come back if the sky turned stormy or at night. I just took a home depot blue tarp and covered the dish below the LNBF and the signal stays on. I guess I need a satellite cover or perhaps I need to paint the dish to prevent glare.

Inomad

 

[telstar_1]

The sun can only cause impairment or outage when the dish and the satellite come into alignment with it such that the dish is focusing both on the sat and the sun together. For the Clarke Belt, this alignment occurs in early March and early October as the noon positioning of the sun rises above and then falls below it. A sun outage should last only briefly, a few minutes at most. Back in C-band, I could observe the signal starting to fade out in early afternoon, then go all snow (analog signal), then fade back in. Moving to the next bird to the west would see a repeat of process.

Any impairment occurring outside of the first week of March or October and in the early afternoon is not from the sun. A sun outage is from radio frequency interference from a prime focus of the dish on the sun. Certain highly light-reflective dishes (such as stainless steel) can also direct focused IR enough to heat up and damage feed components. Solar energy.

 

[ZetaMale]

I can't recall ever having that problem.

 

[mikekohl]

I wrote in some time ago about my signal disappearing on my 10 foot dish when the sun was really shinning. The signal would come back if the sky turned stormy or at night. I just took a home depot blue tarp and covered the dish below the LNBF and the signal stays on. I guess I need a satellite cover or perhaps I need to paint the dish to prevent glare.

Inomad

Do you have a picture of the dish, showing any shiny areas that heat up when the sun is out?
A solid dish of shiny construction can create a lot of heat at the focal point during the midday sun.
If it is tracking the arc, and you are near semi-annual outages such as in February or October, it can
literally melt the feed area. I took a picture of such a situation in Long Beach, CA on a 100 F October day, on
a brand new fiberglass dish. Parts of the feedhorn melted towards the antenna during a solar outage.
The shiny surface had not had a chance to collect a coating of dirt from air pollution. Even if you have
a mesh antenna, it is possible to overheat an LNB or LNBF that is getting direct sunlight. In Indonesia,
one of my colleagues cut an opening in a weather cover to vent it, and then painted the black weather
cover white, which reduced the amount of sun exposure because it reflected away from the LNB area.
I would be concerned about using a blue tarp long term, as it might melt onto the dish at some point.
Good luck!

 

[telstar_1]

I painted C-band feed covers silver-aluminum. This was not because of heat reflected from dish, but to deflect from direct path to feed cover.

 

[clucas]

When it happens again just grab your hose and give the LNBF a light shower to cool it and see if your reception comes back. I’ve heard of problems with the LNBF frequency drifting if it overheats.

 

[iamnomad]

My dish is a 10 foot mesh it has a dark color and not too shiny I have a digital c/ku lnbf model BSC 621. I just bought a different lnbf but it doesn't have the three cable connections like the BSC 621. The add said something about needing a switch, but I don't know what kind of a switch I need. Also there were no instructions for installing it.

 

[telstar_1]

My dish is a 10 foot mesh it has a dark color and not too shiny I have a digital c/ku lnbf model BSC 621. I just bought a different lnbf but it doesn't have the three cable connections like the BSC 621. The add said something about needing a switch, but I don't know what kind of a switch I need. Also there were no instructions for installing it.

A switch (connected at receiver) may be needed for changing polarity if running single coax and an LNBF design that uses a voltage change between 13 & 18 to change from H to V polarity.