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Topic # 239347 12-Jul-2018 21:53
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I have just installed a second TV set about 30 metres from our main TV and Dish S8200 set-top box. Can I use 3 x 10m lengths of cable from Mitre 10 (https://www.mitre10.co.nz/shop/custom-satellite-or-uhf-aerial-extension-kit-blue/p/295481?gclid=CjwKCAjwj4zaBRABEiwA0xwsP5VNwL0guOjM4jVlZvTPJnz-pvPT_o0Y857zgRMlyFQO7Cnhi0hJ9xoCBF0QAvD_BwE&gclsrc=aw.ds) or is a single length better. Would an amplifier ( SAC AE9701 47 - 2400MHz, 13 - 20dB inline amplifier) be advantageous.  


Thanks in anticipation....


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  Reply # 2055460 12-Jul-2018 23:56
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Cable joins always cause a bit of signal loss, so a single 30 m run of cable is better than 3 x 10 m.  But everything depends on how good your aerial signal is and how sensitive the tuner on the end of the 30 m cable is.  If you have a good signal from the aerial and the tuner is reasonably sensitive, it may just work over a 30 m cable.  The cable you are looking at is RG6, and has F connectors, which are both what is recommended for this purpose.  The best option would be to see if you could borrow 30 m of cable from someone (friend, neighbour?) and try it out.  If it does not work, then you will need an amplifier, so then get that and try it.  If that works, then buy your cable.

 

But!  If you are already using two devices on your aerial, then how are they both getting an aerial connection?  If you already have a two way splitter to do that, then you really need to replace that with a three way splitter, rather than using second two way splitter in series, such as the one that comes in that cable package.  When you split the signal with a two way splitter, there is a bit of loss in the splitter, so each of the outputs gets a bit less than half the signal.  So if you then split one of those outputs again, the outputs from the second splitter will be less than a quarter of the level from the aerial.  And if your signal from the aerial is not particularly good, changing from a two way splitter to a three way splitter might cause the existing TV and recorder to have problems.  In which case you would probably need to change the three way splitter to a three (or four) output splitter amplifier.  Unless you get a professional in with a proper signal meter, there is no way to know exactly.


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  Reply # 2055463 13-Jul-2018 00:11
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You might get away with this depending on the strength of your signal but as a matter of principle it is not a good idea to have several joins of cable as each connection point weakens the signal and potentially affects quality. It is better to use a single length of cable wherever possible. You can get cables made to whatever length you need from some Trade Me suppliers and maybe Jaycar also sells different lengths. I'm not sure about an in-line amp. It might help but I would try it first without. 

 

 





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  Reply # 2056005 13-Jul-2018 22:37
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Many thanks for those two super quick replies.

 

I kind of thought joins may be detrimental to signal quality so I'll get a single length. I had forgotten to say I have dual feed cable from the LNB and both have F type connectors. I have them both plugged into the Dish box, but I think only one is necessary so that means I won't have to use a splitter. I'll try with and without the amplifier I have on hand. Thanks again - I'll report back later.


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  Reply # 2056041 14-Jul-2018 08:11
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You are correct, one is LNB in the other is IF out, you could in theory put the cable in the IF out to your new satellite receiver and connect that way but you will restricted to the transponders that your main one in using.

 

As you have a dual output lnb you should go to there.

 

Depending on the LNB you probably dont need to power it from the second receiver, turn off LNB power to start with ( will be in the receiver LNB setup page ) and see how you go, if it does not work turn power on.

 

John





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  Reply # 2057236 16-Jul-2018 16:13
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Just a note that 30m is a substantial run for satellite frequencies. Even if you use it to send an IF feed you are looking at a loss of 7 or 8 dB over 30m which translates to 1/7 th of the signal arriving at the receiving end. See http://www.net-comber.com/cable-loss.html 

 

It's not unfeasible but everything needs to be spot on with your dish pointing etc to maximise signal.


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