C-band discrepancy

[olu]

My C-band dish has dual LNB's, one for Horizontal and one for Vertical. I have signal on the horizontal, but none on the Vertical. Can anyone help?

 

[gabshere]

there are a lot of things that could be going on .... bad coax ends ( connections ), bad coax, wasp ( critters) up in the feed horn area, or bad lnb. if you can access the feedhorn check for wasp this time of year. next would be to check the coax ends . after that swap the cables at both ends to see if you gain vertical and lose Horizontal. (this would verify bad lnb or cable)

 

[Stefan]

Another question is how are the 2 lnbs connected to the receiver and how is the receiver configured to power the LNBs? The reason I ask this is, if your using 13/18v polarity switching and using a 13/18v switch to switch between the 2 LNBs then the Vertical LNB will only be getting 13v. This can be a problem because C band LNBs are often not rated to work at 13v. Some of them will work even though they aren't rated to, but some of them, particularly the higher end PLL LNBs, will not. Actually the same is true for wr-75 flange Ku LNBs. Since these kind of LNBs aren't meant to be used with 13/18v polarity switching they're not designed to work at lower voltages and instead expect to see a constant voltage usually in the 15-20v range.