No channels on V polarity

[flighttothemoon]

Hi all. The reason why I am asking for help on the forum is a problem with sat dish setup that I have had for the last month. Half a year before it, It had been working fine. But a month back one day I could not find around half of channels. Trying to scan again, I noticed that I cannot find channels of V polarity. Only H.
I am using tv tuner Technisat Skystar HD 2 PCI in my PC and circular LNB. Software - DVBViewer Pro.
By now I have tried as follows:
- Tried to install the tuner into other computer. No result.
- Returned the tuner to shop and got a new one. No result.
- Changed LNB to a new one. No result.
- Checked voltage from the both tuners (the old returned one and the new one). It changes from 13 to 18 and back.
- Checked voltage on the end of cable going from the tuner to LNB. Voltage changes.


What else can be a problem? I do not understand. Any help appreciated.

 

[Mikhel]

Get another receiver and check that, if it fails to get the "H" channels, then you might as well have a defective LNB or a bad cable run... altough using a circular LNB there is not much, if any, that can be received.

Cheers

Mike

 

[flighttothemoon]

Get another receiver and check that, if it fails to get the "H" channels, then you might as well have a defective LNB or a bad cable run... altough using a circular LNB there is not much, if any, that can be received.

Cheers

Mike

Another reciever? As i wrote, I returned old reviever to store and got a brand-new one but the problem still exists. The same about LNB. Tried two LNBs.

 

[Mikhel]

Yup another receiver (a STB), to discard anything related to the DVB card.

 

[delta_charlie]

Hi Flighttothemoon, are you located in Russia? What satellite are you trying to receive?

FYI - a circler LNB will not pick up H or V polarity very well, it should only be used on a satellite with circler L or R polarity.

How did you test the voltage at the LNB? I think you might have a bad cable run that is loosing voltage under load. Maybe try using a barrel connector at the LNB and add a short piece of coax with a slot cut in the side so you can test with the LNB hooked up.

Hope this helps, DC

 

[flighttothemoon]

Hi Flighttothemoon, are you located in Russia? What satellite are you trying to receive?

FYI - a circler LNB will not pick up H or V polarity very well, it should only be used on a satellite with circler L or R polarity.

How did you test the voltage at the LNB? I think you might have a bad cable run that is loosing voltage under load. Maybe try using a barrel connector at the LNB and add a short piece of coax with a slot cut in the side so you can test with the LNB hooked up.

Hope this helps, DC

Hi. Yes, located in central Russia and trying to recieve Eutelsat W7 36E.
As to cable, using digital meter, I tested voltage straight from tuner and from the end of cable that goes from tuner, before it goes to LNB. In both cases, voltage changes 13/18. Can it still be the problem in cable if voltage is ok?

 

[Elchucko]

I noticed on Lyngsat that the R polarity are DVB-S2 but the L polarity are only DVB-S.

Is your card capable of receiving DVB-S2?

 

[flighttothemoon]

I noticed on Lyngsat that the R polarity are DVB-S2 but the L polarity are only DVB-S.

Is your card capable of receiving DVB-S2?

Yes, it is. My card is Technisat Skystar HD2 PCI TechniSat SkyStar HD 2 with RC set (Export) [4102/3734]
Like I wrote in the first message, it worked fine for half a year, receiving both DVB-S and DVB-S2 channels.
I suspect the problem is cable, as i have already tried 2 receivers on different computers, tried two circular LNBs. Is there any way to check cable before replacing it? Because it goes from roof and it is quite complicated to wire it all over again. Would not like to do it in vain.

 

[thebaggins]

How about checking the connections first, any small amount of oxidation could be causing problems.

 

[flighttothemoon]

How about checking the connections first, any small amount of oxidation could be causing problems.

How to check it?

 

[turbosat]

Unscrew and look at the connector ends............look for obvious signs of water intrusion like rust, discoloration. Check the center conductor , broken,, or too short to connect properly.

 

[delta_charlie]

Hi. Yes, located in central Russia and trying to recieve Eutelsat W7 36E.
As to cable, using digital meter, I tested voltage straight from tuner and from the end of cable that goes from tuner, before it goes to LNB. In both cases, voltage changes 13/18. Can it still be the problem in cable if voltage is ok?

Hi Flighttothemoon, yes the cable or more likely a connector could have corrosion and this can cause a loss of voltage but only when under load. A digital volt meter is so sensitive it will show voltage on an open cable but when a load is applied the voltage can drop to nothing. That's why I suggested using a barrow connector and a short piece of coax with a slot cut in it so you can test the voltage at the LNB to see if it holds under load. If it is dropping try checking near the receiver to verify the voltage is holding there. This should let you know if the cable/connectors are the problem or if it is something else.

Let us know if you figure it out, DC

 

[flighttothemoon]

The cable was the problem, indeed. Tried a new cable and could receive all other channels.

 

[flighttothemoon]

Okay, early to be happy. Received V-polarity channels but the strange thing is they do not work. I click on them but no picture comes out.

 

[Kallesatman]

For what it is worth; try rescanning the satellite now that you've replaced the cable. It can only help.

 

[flighttothemoon]

For what it is worth; try rescanning the satellite now that you've replaced the cable. It can only help.

Rescanned many times. Able to receive more channels, not all V-polarity channels though, not as before. And picture on these received V polarity channels is either absent or tearing, whereas picture on H-polarity ones is perfect. Very weird.
I also tried to check reception with portable satfinder connected between LNB and receiver. So, reception is good but sometimes 22 khz lamp on blows out for a second and beeping signal weakens. What could it mean?

 

[Kallesatman]

Hi all. The reason why I am asking for help on the forum is a problem with sat dish setup that I have had for the last month. Half a year before it, It had been working fine. But a month back one day I could not find around half of channels. Trying to scan again, I noticed that I cannot find channels of V polarity. Only H.
I am using tv tuner Technisat Skystar HD 2 PCI in my PC and circular LNB. Software - DVBViewer Pro.
By now I have tried as follows:
- Tried to install the tuner into other computer. No result.
- Returned the tuner to shop and got a new one. No result.
- Changed LNB to a new one. No result.
- Checked voltage from the both tuners (the old returned one and the new one). It changes from 13 to 18 and back.
- Checked voltage on the end of cable going from the tuner to LNB. Voltage changes.

I looked at the satellite that you are trying to receive and I checked the channel chart here: SatBeams - Satellite charts - Channel list - Intelsat 10-02 (Intelsat 1002, Intelsat Alpha-2, Intelsat X-02) / Thor 5 (Thor 2R) / Thor 6 and what I came up with is that there is a mix of FTA'S that have linear which is V / H polarization and then there is the R / L circular polarization. If I read correctly, maybe not, it is my understanding that you are using a lnb that is circular polarized. That lnb will not give you the V / H polarized signal. You will have to have a lnb that is capable of providing a linear output and a circular output. Also that chart when you go to 36 will tell you what is available on the transponders with the pertinant information as well as the polarization be it linear ( V / H ) or circular ( L / R ). I hope that this might help you. Also make sure that the lnb has the proper skew setting for the satellite. I don't think that you have this antenna motorized so the skew setting is also very important. Will be interested to see/hear what progress you are making. Good luck.

 

[AcWxRadar]

Flighttothemoon,

Since you have already found some trouble with your cable, could it be that there is still a cable or connector problem? I would rule this out first by taking your components as close as possible to your dish and running the absolute shortest cable you can possibly use with exceptional connectors and connections that are made well.

If you achieve the same results after doing this as you are when using your current cable run, then you can at least rule that out as a possibility and work on the other possibilities.

I know that it won't be an easy task to do this since you are using a PCI card with your PC, so it won't be as simple as just hauling a STB and a portable TV out there, but I highly urge you to try it if the weather works with you.

Judging from the fact that your system operated well previously, and since you have already ruled out any defect with the PCI card and the LNBF, then that leaves me to question the cable and the dish alignment. Rule out the cable first, then check your dish alignment to ensure that it didn't get moved in any way or that your LOS didn't get blocked by a tree limb that has been growing slowly over time, etc.

Also, I am not certain if you mentioned it or not, but do you have any external switches in use here? If you do, remove them entirely and run a straight cable between the PCI and the LNBF and test that way to rule out any possible defects there. I didn't think you had any switches, but included this idea just in case.

I reread your last post here and now I am leaning towards the dish alignment and/or some obstruction in your LOS - based upon your report of how the signal meter responded. Maybe a weakened signal is not welcomed by your PCI card.

Wishing you luck in isolating the trouble and repairing it!

RADAR

P.S. Welcome to SatelliteGuys forum! Great to have you join us!

 

[flighttothemoon]

Thank you all for trying to help me. It looks like the reason of the problem is quite simple - dish alignment (maybe it moved because of strong wind at night), as i changed card, LNBF, cable, and I dont have a switch. What I have now is almost all channels as before, but picture of V (only V. H-ones work great) -polarity ones (in Dvbviewer I have H- and V-ones) is kind of broken. Am i right? Alignment?

 

[thebaggins]

I've had that happen before H polarity fine but V polarity had either weaker (lower) quality or jumping numbers, my fix was to bump dish east or west to max out V polarity and monitor H to make sure I didn't go to far