Freeview/SBS/ChinSat LNB multi switch help

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mjc159

4 posts

Wannabe Geek

#95371 1-Jan-2012 16:19

Hi All

I currently have a MySky running off a standard Sky dish with a Sharp dual throat 4 output LNB. In addition I have ChinaSat 6b (C band) running independently in another room, for which I have just purchased a new DishTV Box.

I was hoping to get freeview and a few of the Oz channels on the DishTV box, but am having a few issues.

My wiring configuration is probably a complete balls up, but here's what I've done.

I have run a second cable from the Sky LNB to 3x4 multi switch (13v input), along with the ChinaSat cable (18v input).

I can get a few of the Ozzy channels but not CH9 or Freeview.

Questions:
Is the second cable connected to the sky LNB looking at D1 oe D2?
Do I need a switch with more than 1x 18v input?
Should I connect everything differently?

RunningMan

9184 posts

Uber Geek
+1 received by user: 4834

#563527 1-Jan-2012 16:49

The 13v input will be holding the cable going to your sky dish in vertical polarity - the result (as you've noticed) is a handful of Aussie bits and pieces, and no Freeview.

It will be looking at the correct satellite (D1), but on the wrong polarity (V not H).

The best solution would be a 2 way DiSEqC switch instead of the multiswitch, as this will pass the correct DC voltage (13 or 18) through to the LNB, which selects the polarity (V or H).

What polarity are the ChinaSat signals you are trying to recieve? If they are vertical only, then just swap the 2 inputs to your current switch (i.e. ChinaSat to 13v and D1 to 18v).

RunningMan

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+1 received by user: 4834

#563530 1-Jan-2012 16:56

I should have added, the current multiswitch you have selects between the inputs based on the DC voltage the STB sends to it (I.e. 18 or 13v), however, as this same voltage is also passed through to the LNB to select the polarity, you will only ever see half the signals on a given satellite.

A multiswitch is best used for a dual output LNB that points to one satelllite so that several STBs can independantly get either the H or V polarity. So, one satellite, several TVs.

A DiSEqC switch such as this is designed for one STB to connect to several satellites, and passes the H or V signal through, so you can select whatever you want. It takes a bit more to set up on your STB, but not that difficult really...

mjc159

4 posts

Wannabe Geek

#563531 1-Jan-2012 16:56

ChinaSat is H.
Odd thing is that some of the channels from the sky LNB are V and some are H?

RunningMan

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Uber Geek
+1 received by user: 4834

#563534 1-Jan-2012 17:02

mjc159: ChinaSat is H.
Odd thing is that some of the channels from the sky LNB are V and some are H?

All the Sky and Freeview transponders on D1 are Horozontil. The only stuff that is Vertical is Aussie.

A slightly Mickey Mouse solution would be to connect the Sky LNB to the 18v input (horozontil), ChinaSat to the 14v (vertical) then rotate the LNB on the dish by 90 degrees (so H & V are swapped). You'd then need to tell your STB to output 14v all the time for ChinaSat so it connects to the right input on the switch. This should work, but is far form an ideal setup...

The DiSEqC switch really would be the preferred method.

mjc159

4 posts

Wannabe Geek

#563538 1-Jan-2012 17:14

Are there limitation with the DiSEqC switch with regard to running another STB in the bedroom? They generally on have one output.

RunningMan

9184 posts

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+1 received by user: 4834

#563542 1-Jan-2012 17:26

The limitation of the DiSEqC switch is that they are really designed for one STB, with several sats.

If you want to use multiple STBs with multiple sats, you'd need a more complex multswitch, such as this or this.

With either of those, you'd still have one cable from your Sky LNB to the Sky Box. You'd then need 2 cables from the Sky LNB to the multiswitch, and another from the ChinaSat LNB (2 cables, and a dual output LNB if you want both polarities) to the switch.