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Topic # 87472 29-Jul-2011 16:32
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Hi there,

After some help if possible.  I have a roof mounted FM aerial with its cable running to a ground floor distribution box.  My question is is there a way to carry the FM signal over the cat5 cables that we have running from the distribution box to the lounge, where the stereo is?   Can this be done?  


Thanks,

Nick

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  Reply # 499507 29-Jul-2011 17:18
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It may be possible but remember that cat5 isn't shielded.





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  Reply # 499524 29-Jul-2011 18:29
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I take it that running a proper antenna feeder is not an simple task here? Not ideal, unshielded and impedance is a little way off what you want for balanced FM feed - you are replacing balanced feed I guess and not trying to use balanced UTP cable in place of 75 ohm coax? But if the signal level is decent, it's probably going to work well enough for FM (being reasonably narrow band) and most likely a better than an indoor antenna.


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  Reply # 499536 29-Jul-2011 19:06
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alexx:
....and most likely a better than an indoor antenna.


That should read "most likely a better option than an indoor antenna".

Plus, it should be mentioned that 300 ohm ribbon cable (balanced) is unshielded. If the existing feeder from antenna to ground floor distribution box is 75 ohm coax, then perhaps a good idea to use a balun where you connect to the cat 5 cable.

If in doubt, use pins 4-5 for the FM signal.
http://en.wikipedia.org/wiki/Category_5_cable

You could even experiment with grounding the unused pins, to see if this helps provide some shielding effect (if needed).

Edit: fixing formatting.


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  Reply # 499548 29-Jul-2011 19:32
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Hi, yes as mentioned cat5 is fine although the losses are somewhat greater than RG6 etc but in short lenths (<25m) should be fine, the big issue is lack of shielding as mentioned.

Cyril



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  Reply # 499691 30-Jul-2011 11:54
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 I have no training on this stuff but looking over the web I came across these baluns that sound like they might do the job?  One at each end of the cat5 run.  It's not that long actually - maybe 15 meters in total.
http://www.muxlab.com/products/ve_catv_balun.html
Not sure where I would get this type of thing in NZ.  Any ideas?


Thankss,

Nick 

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  Reply # 499721 30-Jul-2011 13:26
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Hi, yes thats what you need, PDL's Lexcom range does have similar units, however they only come as complete panels and kits, I suggest for what you need get them from the states, with the $ the way it is should be easy, just shipping kills it.

Cyril

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