Splitter for satellite

[TPUBON]

I have a dish with two cables coming from it to allow two TV's to be connected to it. I put a splitter in one of the cables to run a third tv. It works but doesn't get some of the stations it used to get. Sometimes it will and other times it won't. The question is does it take a certain type of splitter or it just can not be done?

[johng]

It can be done but....there are horizontal and vertical polarization and 11 /12 ghz frequency switching (and maybe C band if its a big black dish)

 

Short answer get a (more) multi output LNB then each receiver can control H/V and 11/12 ghz independently via a separate coax feed cable.

 

At the moment your 2 recievers are competing to control H/V and frequency one will always loose.

 

 

 

 

[TPUBON]

1 hour ago, johng said:

It can be done but....there are horizontal and vertical polarization and 11 /12 ghz frequency switching (and maybe C band if its a big black dish)

 

Short answer get a (more) multi output LNB then each receiver can control H/V and 11/12 ghz independently via a separate coax feed cable.

 

At the moment your 2 recievers are competing to control H/V and frequency one will always loose.

 

 

 

 

Thanks, after I googled what a LNB is, I now understand. Like I said, the LNB that is there now has two leads coming off of it. If I'm lucky, maybe there is a third. Any idea of the cost of a LNB or would another dish be a better deal?

[RichCor]

LNBs usually come only in one or two port configurations, as that's all that's ever needed. 

 

Satellite broadcasts are sent from the satellite over two nearly identical signal paths. Now there's a problem as there are two available signals but only ONE can be sent over a single cable at any given time. An electronic circuit in the consumer dish feed horn selects one (H or V polarization orientation) and the LNB then sends the selected signal stream down the cable to the Set Top Box. 

 

If both signal streams are needed simultaneously then you either need a 'dual' LNB (each F-connector controlled independently), or each F-connector dedicated to only H and the other to V polarization to pass on the different signal paths.

 

The cable can only pass ONE of the TWO signal paths, as both use the same radio frequency spectrum. The Set Top Box selects which by sending +12v or +18v down the cable, forcing H or V to be selected and powering the dish electronics. So connecting two Set Top Boxes to one cable potentially messes with the H/V +12/+18v polarization selection process. If one box is already sending +18v then whatever polarization that's assigned to is the feed that gets sent down the single cable to the splitter.  

 

One Set Top Box, Single-feed LNB, one cable.

Two Set Top Boxes, Dual-feed LNB (two F-connectors) and a cable to each.

Three or more...  either get another dish with more F-connectors

... or ...

get more electronics to handle distribution. A mulit-set-top-box distribution box is normally known as a 'SWITCH'. It accepts FIXED H and/or V signal feeds from the LNB (or Dual-LNB) and then acts as the middleman for any connected Set Top Box.

 

Connecting a 'SWITCH' has other useful options. Some have Multiple Inputs as well as Multiple dedicated outputs so you can connect multiple LNBs looking at different satellites H/V feeds, and allowing a connected Set Top Box to electronically request whatever feeds available to the 'Switch' to be delivered to the Set Top Box.

 

Note, some satellite providers, like TRUE, put all their signals on only one polarization feed, and with these you split the resulting LNB feed to many Set Top Boxes using simple signal splitters (made for satellite cable).

 

But when channels are part of the H or V feed, then something has to be in place to select and send the correct H or V signal down the cable for the Set Top Box to tune. 

[Caiman]

We changed the 2 output to a 4 output LNB when we added a 3rd point from our KU Band dish. This was advised by a local satellite installer.

[RichCor]

7 minutes ago, Caiman said:

We changed the 2 output to a 4 output LNB when we added a 3rd point from our KU Band dish.

Had a built-in 'switch' to support the 4 outputs.  Same-Same, but different (integrated).

[Pib]

You will need a "multiswitch", power or unpowered.  Powered is better if you have long cable runs/minimizes signal strength and voltage loss.   A multiswitch allows input from multiple LNB outputs to be distributed out to multiple settop boxes with the multiple boxes inferring with each other and causing various problems...like the problem you have having where two of the boxes are occasionally confusing the LNB ouptut...getting confused between a horizontal oriented channel and a vertical oriented change.    Below are some examples of unpowered and powered "multiswitchs."  

 

And don't confuse a splitter with a multiswitch...they are very different devices.

 

Unpowered multiswitch...just passes thru LNB power from the settop boxes to the LNB(s).

 

 

Powered Multiswitch....its own power supply supplements the power to the LNB(s) to minimize voltage LNB power voltage drop which results in a more reliable power voltage to the LNB.  Below is an example of powered multiswitch....a 5 input, 6 output multiswitch but the 5th input is just a terrestrial input  Very, very similar (maybe the actual one)  I have used for around 8 years.  It takes the input from four C and KU band LNB outputs (i.e, a two output C band LNB and a 2 output KU-band LNB)...and then distributes those signals to 6 different settop boxes without the boxes interferring with each out and confusing the heck out of the LNBs.   Its 18V power adapter died about a year ago after 7 years of use and it caused some horizontal-oriented channels to not be display because the power coming from the settop boxes due to my long cable runs to the LNBs via the multiswitch was causing a several volts voltage drop making the LNB think it was getting supplied 12-15 volts which is required for vertical oriented channels...the C-band LNB was getting confused as to whether a vertical or horizontal oriented voltage/channels was being asked of it...end result a "No Signal" message on the TV for some channels.  Replaced the power adapter (cost about Bt150)....good to go again  on all channels. 

 

 

 

9Sat multiswitch webpage...a store here in Bangkok I have bought a lot of TV and other electronic stuff from over the years.  Very good prices.  Lots of satellite TV installers get their stuff at this store and then go sell it/install it for you.  I go directly to the store to the buy...but you can order via phone also I guess as I see ladies taking orders via phone whenever I visit the store.   Google Translate is your friend at this website

http://9sats.com/product/product.php?cat=75.77

 

 

Edited February 22, 2018 by Pib

[KittenKong]

Quad LNB. 459B. Problem solved.

https://www.lazada.co.th/hisattel-lnb-ku-band-universal-4output-hi-u4-4388345.html

[johng]

Don't forget another length of RG6 Coax cable 2 x F connector
and some self amalgamation tape to seal F connector at LNB from water damage.

[Pib]

OP,

   Assuming you have a big C-band dish (approx 1.5 meters in diameter) along with a C-band LNB since you said you have an LNB with two outputs/cables coming from it.  While a small KU band dish/LNB can also use multi-output LNB like shown in KittenKong's reference seems the great majority of folks in Thailand who use KU band are using little dish approx 75cm in diameter with a one output/cable LNB mounted on it....like those that come from TrueVisions.

 

    Anyway, you need to understand that setup box send either a 13VDC (approx 11 to 15V) or 18VDC (approx 16 to 20V) signal depending on channel polarization/selected to the LNB.  Each channel willl have what is caused a horizontal or vertical "polarization" when it's transmitted from the satellite along with a specific frequency and other identifying coding.    For the LNB to receive a channel from the satellite it needs to be in the polarization modem as being transmitted from the satellite.  The LNB has to receive certain info "from the settop" box or middeman device like a multiswitch to be in the proper polarization mode which changes which little antenna within the LNB is used and also changes the LNB frequency band to receive the channel.   

 

    The voltage used to select vertical polarization is approx 11 to 15VDC  and for the horizontal polarization approx 16 to 20VDC.   And in any case where the LNB receives a voltage of say in the slightly above 15V to slightly below 16V the LNB can get confused because it's not sure which polarization is really being asked to switch to...it's like no-man's land. 

 

     Let's say the LNB sees 15.5V being sent to it (a no-man's land voltage) but actually the settop box you are using is sending an 18V horizontal polarization/channel selection.  But due to long cable length between the box and LNB which causes a several volts voltage loss "or another box on the same LNB cable due to using a "splitter" is set to a vertical polarization channel which pulls down the voltage" that 15.5V is  right in the middle of the polarization voltages.  The LNB incorrectly decides to switch to vertical polarization mode which means the horizontally polarized channel you are wanting to view appears as "No Signal", just a black display, just nothing, etc.

 

    In your case since you are using a "splitter" that splitter is feeding through voltages from two settop boxes and if one box happens to be set to a vertically polarized channel (13V) and the other to a horizontally polarized channel (18V) the LNB ends up seeing an average voltage of 15.5V and the LNB can make the wrong polarization selection due to that no-man's voltage.  And not only you can't see the selected channel but it might mess up the channel the person is viewing with the other box in another room.   But if both boxes happen to say be set to a horizontally (or vertically) polarized channel then the voltage being sent to the box is not affected...neither box messes up....both get to view their different channels.

 

   Anyway, you generally must use a "multiswitch" not a splitter when dealing with multioutput LNBs....just completely different animals although they look very similar.   Or maybe you can find a four output C band LNB but the downside to that is you need to run additional cables from your LNB to your boxes.  But with a multiswitch you just need a two output LNB run the multiswitch...and then from that multiswitch is branches out to ever how many boxes you have.  If you have a 2 input/6 output multiswitch you just hook the 2 output LNB to the multiswitch and then hook 1 to 6 to that switch.

 

   Now someone might say I have a TrueVisions KU band setup....it only has a one output/cable LNB but I running two boxes off it with a "splitter."  A splitter is OK in this case....will not cause a problem "because the TrueVision boxes and channels "only use the horizontally oriented" voltage/channels.  That is, the boxes "only" use the 18V horizontally oriented voltage...True only transmits its channels using horizontal polarization.  Therefore, two boxes on the same line going to the LNB via a splitter are both sending 18V...always sending 18V regardless of channel selected...one of the boxes never sends the 13V vertical orientation voltage which would pull down an 18V horizontal orientation voltage from another box like how "C-band" setups/LNBs/boxes can send either polarization voltage depending on the channel you want to view.

 

 

 

 

 

[KittenKong]

Dont think the OP actually specified if his dish is C-band or KU-band, but Lazada also have C-band quad LNBs for about the same price. Such a quad LNB (of the right type) would run up to four boxes from one dish without any need to consider switching, polarity or H/L compatibility. That should be enough for most domestic uses. Seems a lot more straightforward to me, and is particularly convenient if the set-top boxes are at different ends of a building. Quad LNBs also neatly avoid you having to worry about waterproofing splitters and connections that might be exposed to the elements.

For a larger installation a powered multiswitch does a good job:

https://www.lazada.co.th/mastersat-satellite-multiswitch-5x8-adapter-2-7-8-8024663.html

There are also multiswitches that can be used with two dishes, with built-in DiSEqC switching. This is very handy for places like Europe where some people in a house might want to watch Euro channels from one satellite and others might want to watch UK channels from another.

https://www.deschotelshop.nl/image/cache/catalog/Producten/Switch/emp-centauri-ms17-26piu-6-diseqc-profi-class-multiswitch-0-1-3-600x600.jpg

[Pib]

All a quad C or KU band LNB usually is a two output LNB "with a multiswitch built-in " which turns it into a four output LNB.

 

For example below quad KU LNB where it specifically talks the built-in multiswitch in order make it a quad LNB.    It's probably easier for a person to have a multiswitch in his ceiling/residence at the junction point where TV cables spreadout/run to your different rooms/settop boxes like in my house.

 

That way you only need two cables running from that multiswitch inside your residence (protected from the sun & rain) up to the two output LNB mounted somewhere outside on a dish....possibly mounted a good distance away and somewhere high that is not easy to get to.   

 

Just less total cabling to deal with.   Instead of four cables from your settop boxes "all the way" to the LNB, it's four cables "part of the way" to the multiswitch inside the house and then just two cables for the rest of the way to the LNB/dish.