Polarity Question

[tonydix]

I was trying to receive a signal from Amazonas 61 which is labled in the satellite info eg Lyngsat as being horizontal. A local friend says he gets the signal as vertical. Does this mean that his LNBF is postioned at a skew 90 degree difference from mine.
I guess I should know the answer to this !
Thanks
Tony

 

[Lak7]

The simple answer is "yes" IF you 2 are using the exact same LNBF and Receivers.
Are you able to Lock any other TPs on that Sat, do the Polarities agree with Lyngsat?

 

[RT-Cat]

Tonydix, could you post a large picture of that amazing 24 foot BUD. Avatar pic is a bit small.

RT.

 

[tonydix]

Yes we are able to lock other transponders on this satellite. The reson I was asking was that his reception of a marginal signal seemed better than mine. Ie he had no pixellation of one transmission whilst I had some. He was using Vert polarity whilst I was using horizontal. I shall have to try some experimentation !!

 

[Keith Brannen]

Yes we are able to lock other transponders on this satellite. The reson I was asking was that his reception of a marginal signal seemed better than mine. Ie he had no pixellation of one transmission whilst I had some. He was using Vert polarity whilst I was using horizontal. I shall have to try some experimentation !!

Could be that his LNB skew was slightly more optimized than yours (even if it is 90 degrees off!) so you might want to try some slight adjustments (if we are talking about fixed dishes).

 

[Lak7]

What type of Feedhorn are you using?

 

[tonydix]

This was on a 6 foot offset Ku band fixed dish with a LNBF, not on the C band monster, therefore no feedhornThanksTony

 

[Lak7]

Ah, that makes sense
The Spitfire should have markings for setting the correct polarity.

 

[Corrado]

Some of the inexpensive C or Ku band LNBFs I have are less than clear of where the "0" skew position is located. It further complicates when some receivers like Motorola's 4DTV receivers needed the "rotated 90 deg" selected in the menu to operate even though the feed wasn't on the dish. Sometimes I've needed to experiment myself using known published TP parameters to verify if I was setting up correctly.

 

[guacharaca]

There is another potential explanation. Your friend who recieves the Horizontal TP as Vertical is not getting enough voltage out at his LNB. If he does receive horizonal TPs with that particular LNB somewhere else, then the first explanation written above is correct such that his LNB is 90 degrees out of kilt.