Signal on both wires of a satellite shotgun cable

[Guyt]

Hi ,

I've just had my main Q box rewired from the dish and have been testing the shotgun cable. If both are screwed in to the box I get a 90/90 signal & quality which is great...however it apears only one cable is working. To cut a long story short , I've swapped the connections over at the dish and the non transmitting cable changes over, which says to me that one of the ports on the LNB isnt transmitting. 

Question is ....should both cables ( and ports on the LNB ) be transmitting SkyQ channels. ?

To check this at the Q box, if I unplug one cable the signal quality and strength remains the same. If I unplug this working cable and plug the other one in ...no TV ...nothing. 

Does the LNB need swapping and if so..is this a free sky fix ?

Ta

Guy

[MightyQuinn]

Hi @Guyt   Are you sure that the centre copper core is not bent and are inserted in the socket correctly. If it was Sky that rewired it then it will certainly be a free fix.

[nigea99]

hi @Guyt 

I am not too sure I fully understand what you have tried to do.

On SKY Q the signal condition indicator is misleading as it does not show the channel you are watching but a fixed transponder set in the engineers menu

the cables to the dish carry the different polarities  - one horizontal & the other vertical - if one was not working you would looose approx half your channels 

Disconnecting just the cable with the polarity of the test transponder would probably show as a loss of signal even though the opposite polarity channels would be working

[Guyt]

Ok I will try to explain again 

Both cables plugged in the main Q box. All seems to be fine. 

Remove one cable , all seems to be fine. 

Remove the 2nd cable ..no signal ( as you would expect. ) 

Re insert the first cable removed....no signal 

Re insert the 2nd cable all fine. 

If I swap the cables over at the LNB ..the cable which is "transmitting signal " swaps ....ie there is only one port on the LNB transmitting signal 

Make sense ?

[nigea99]

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@Guyt wrote:

Ok I will try to explain again 

Both cables plugged in the main Q box. All seems to be fine. 

Remove one cable , all seems to be fine. 

Remove the 2nd cable ..no signal ( as you would expect. ) 

Re insert the first cable removed....no signal 

Re insert the 2nd cable all fine. 

If I swap the cables over at the LNB ..the cable which is "transmitting signal " swaps ....ie there is only one port on the LNB transmitting signal 

Make sense ?

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It should make sense, but my brain is not working fully

I have to ask are you relying just on the status indicator or are you checking different channels to determine if the cable is working ?

The default transponder is Vertically polarised so,  as I mentioned,  if you only have the cable connected to the horizontal  polarity connection then  the signal indicator will indicate no signal but actually watching a channel that is horizontally polarised should work - if that makes sense 

[nigea99]

Hi again @Guyt 

I have had a further think about what you have tried  & if I have understood what you have done correctly then it is acting just the way I expect due to the different polorities & the fact the indicator only shows the 'default' vertically polarised channel 

[Guyt]

ok , so how do I find a horizontally polarised channel ?

[nigea99]

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@Guyt wrote:

ok , so how do I find a horizontally polarised channel ?

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Please see :

https://www.lyngsat.com/Astra-2E-2F-2G.html

[Guyt]

Thanks all....As advised in this discussion, it appears the signal meter only works for vertical polarisation .

if I plug in both cables and select a vertical channel ...then remove one or the other cable, the channel drops. I can then still select horizontal channels which must be coming down the other wire. 

Similar process the other way round proves same for verical channels. 

Thanks for help 🙂

[nigea99]

@Guyt 

I think the signal indicator on SKY Q does cause a lot of confusion due to it being set to a single transponder (frequency & polarisation) 

Every other receiver I have ever used (both SKY and various multi-satellite receivers over 20+ years) report the 'current' channel