Reception of channels with horizontal polarization works, vertical not

[tomdegetel]

Hi,

I have a new dish pointed corectly toward HELLAS2 (39E) but I can't receive ANY channel sent with vertical polarization. Channels with horizontal polarization works perfectly.
The signal strength shows 90% for all channels with horizontal polarization but 0 for all those with vertical polarization.
The LNB is universal and I have also tried to replace it by another one. Its rotation (skew) is correctly set, according to my location (24 degrees clockwise). I have tried to turn it to different positions around 360 but no luck with reception of channels with vertical polarization.
Any idea what to do?

Thanks in advance

 

[Brct203]

Hi Tomdegetel, welcome to SatelliteGuys!

sounds like maybe a voltage control problem - maybe the receiver is supplying a voltage too high when in vertical mode and the LNBF remains on "horizontal"

An easy test would be to rotate the LNBF by 90 degrees and scan and see if this time you get vertical channels only.

I would also suggest you try this setup on another satellite and see if the problem is similar, so that we can rule out a reception (footprint) limitation (according to the listings on Lyngsat I don't think this is the case)

 

[KE4EST]

to SatelliteGuys tomdegetel!
Is this only happening on 39E or have your tried other satellites?

 

[tomdegetel]

Hi Tomdegetel, welcome to SatelliteGuys!

sounds like maybe a voltage control problem - maybe the receiver is supplying a voltage too high when in vertical mode and the LNBF remains on "horizontal"

An easy test would be to rotate the LNBF by 90 degrees and scan and see if this time you get vertical channels only.

I would also suggest you try this setup on another satellite and see if the problem is similar, so that we can rule out a reception (footprint) limitation (according to the listings on Lyngsat I don't think this is the case)

Thanks for your advice.
I checked the voltage, the receiver is sending 12,8V at all time.
Tried to put a little Sat finder device between the LNB and the receiver, at receiver side. It shows a proper signal at all time. When I switch to horizontal polarity, a led is shortly flashing and then it lights up, indicating the H polarity. When I switch to vertical polarity channels, the led is flashing every 3 seconds and that's all.
I have tried to rotate the LNBF by 90 degrees in both directions, the signal on Horizontal channels drops to zero and the one of Vertical channels remains zero at all time.
Could this be related to obstacles? There might be an obstruction caused by a building at the horizon but I'm not sure. Or would the obstacle affect both horizontal and vertical polarity?

 

[tomdegetel]

to SatelliteGuys tomdegetel!
Is this only happening on 39E or have your tried other satellites?

I wish I could say. But the dish has been fixed on the neighbour's roof and I can't change it .

 

[Magic Static]

Voltage output from receiver isn't good. You need about 18v for horizontal operation and about 13v for vertical. Since you only see the 13v it sounds like the LNB is rotated 90° off so it gets Horizontal channels in Vertical mode. There maybe a setting in the receiver for optional voltage settings, like switching H & V or 12v operation only. You might check and see that it it is correct.

 

[Brct203]

Thanks for your advice.
I checked the voltage, the receiver is sending 12,8V at all time.
Tried to put a little Sat finder device between the LNB and the receiver, at receiver side. It shows a proper signal at all time. When I switch to horizontal polarity, a led is shortly flashing and then it lights up, indicating the H polarity. When I switch to vertical polarity channels, the led is flashing every 3 seconds and that's all.
I have tried to rotate the LNBF by 90 degrees in both directions, the signal on Horizontal channels drops to zero and the one of Vertical channels remains zero at all time.
Could this be related to obstacles? There might be an obstruction caused by a building at the horizon but I'm not sure. Or would the obstacle affect both horizontal and vertical polarity?

I don't think it would be obstacles as they would typically affect both polarities.
After you rotate the LNBF you need to do a blind scan. Depending on what the problem is, either you will get the Horizontal channels, but labelled as Vertical (case 1), or you will get the Vertical channels labelled as Horizontal (Case 2), or both (Case 3).
If you get case 1, the problem is likely that for some reason the satellite Vertical transponders are not getting to your area. But based on Lyngsat listings that should not be the case.
If you get Case 2, which is likely, (also with your info that the voltage is 12.8V at all times), it means the receiver might have a voltage problem and is not switching to the higher value (and that maybe your LNBF was rotated by 90 degrees in the first place)

 

[a33]

Tried to put a little Sat finder device between the LNB and the receiver, at receiver side. It shows a proper signal at all time. When I switch to horizontal polarity, a led is shortly flashing and then it lights up, indicating the H polarity. When I switch to vertical polarity channels, the led is flashing every 3 seconds and that's all.

This suggests to me, that the sat-finder recognizes the hor/vert difference. That can only be recognized by the voltage it measured, I would say.

However you say the voltage stays 12,8 volts, also when you choose a horizontal channel? Sounds strange.....

Greetz,
A33

 

[a33]

BTW: Tom started a parallel-thread here: Reception of channels with horizontal polarization works, vertical not
So to not do unneccesay work: check there also.

greetz,
A33

 

[spongella]

Make sure that your STB is programmed for both Horiz. and Vert. polarity reception. Some give you the choice of All, Vert, or Horiz.