Titanium PLL LNB

[bpalone]

How does the Titanium PLL LNB change polarity? I question as I was wondering if cold effects it's performance in switching polarities. Has gotten somewhat chilly the last few days, i.e. below zero F. Just powered up the Ku band and had some transponders/channels come booming in and others just plain not show. I didn't take the time to check polarities, but just assuming that is the issue. Reminds me of cold servo on old C band system, when it got this cold or colder.

Thanks in advance.

 

[KE4EST]

Voltage switched. Cold should not effect it.

 

[bpalone]

OK, then there are actually two antennas and it electrically swithces between them?

 

[KE4EST]

Yes, two antennas.

 

[bpalone]

Thanks.

 

[Dee_Ann]

Won't the cold actually help it?

 

[KE4EST]

Yep electrons love cold!

 

[Dee_Ann]

Well I figured with the heat sinks on them that they need to stay cool. I have found over the years that when electronic things get hot, they go wonky.
And I saw on more than one movie and science show where they supercool the LNBs of satellite dishes with like liquid nitrogen when doing science stuff.
As I recall, supercooling it causes it to have less noise. Or something like that. Right? So what about having some method to cool LNBFs? Or is that just for the science stuff?

Also, one last question. How is it that they always say that the very cold temperatures on Mars, the Moon and outer space will kill electronics?
I don't understand that, it seems to conflict other things I have heard, like supercooling satellite stuff?

Oh and one other thing. I have read that most TV satellite systems keep the LNBF powered up in the winter time to keep them warm. Um, wut???

 

[Cham]

Been up north here for many winters, LNBs and LNBFs work fine at -40. Polarotors on the other hand...

 

[Titanium]

Yep... LNBFs love the cold (especially if they don't drift frequency)!

Check your connectors. Cold weather will cause connectors to suck out and frequencies can roll off or voltages drop. The freezing ground can cause frost heave and throw the dish of of the arc.

 

[iBoston]

The freezing ground can cause frost heave and throw the dish of of the arc.

That is MY FEAR.

 

[Babadem]

That is MY FEAR.

How deep is the hole you planted your dish in? My experience here is the hole should be at least 3 feet deep.

 

[KE4EST]

Yep if above the mason dixon line I would go at least 3 feet below that and you can get away with less sometimes. Here frost line is less and really rocky I can get away with 20-24 inches just fine on a ku dish.

 

[jorgek]

Up hear the municipal code specifies frost line is 4 feet deep. As well never any problems with cold affecting LNB. PLL LNBs have survived 2 winters so far. Also the Stab 90 motor tolerates the cold well.

 

[iBoston]

It was dug down 4 feet. Time will tell.

 

[Blindowl1234]

When the ground froze was the only time my dishes were solid lol. With the lousy clay soil in the spring and fall I could dig 6 feet and still hit muddy water.
Lining up the Ku dishes was a spring and fall event for years.

 

[wallyhts]

When the ground froze was the only time my dishes were solid lol. With the lousy clay soil in the spring and fall I could dig 6 feet and still hit muddy water.
Lining up the Ku dishes was a spring and fall event for years.

You live near the river?

 

[Cham]

I planted my 10' dish on 3 10' x 12" piles to minimize frost effects that can go down 6-8 ft here...

Shouldn't be that much frost in the ground on the east coast (Boston) and south of Kansas etc., you might get a week of really cold but it warms up periodically enough to keep the frost from going very deep. Local construction or foundation type companies should know how deep local frost goes.

Freezing/thaw cycles can cause a lot of problems with connections, and as Brian suggests above make sure connections are well weather-proofed to avoid moisture incursion.
Really cold weather can cause the center conductor to shrink/shorten and actually pull out of the connection if it was cut too short (F connectors). Of course the longer the run the worse the affect, as well as the material used such as copperweld versus pure Cu. (think Cu suffers from cold shrinkage worse..?) Up here I always leave an extra mm or so to compensate for cold "shrinkage".

 

[Blindowl1234]

Wallyhts, Nope just a very high water table I'm told. I can take a post hole digger and hit water at 18"-24". In the winter the yard is a swamp that you can sink in with boots on lol. Used to be all farm land years ago, at least there is no rocks anywhere to be found.