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Discussion Starter · #1 ·
hello all,

i am installing my first antenna for my local channels when i switch to dbs, and fm stereo. i am wondering about future digital compatabilty issues. mainly should i use twin lead 300ohm wire(less cost, easier install) or do you have to use rg-6 coax for ota digital(when it is finally available in rural arkansas!!!).

thanks for the help guys....
 

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300 ohm twinlead is best if installed properly

Most people don't install it correctly.


RG-6 is more common these days and will work

fine.


A good analog antenna is a good digital antenna

Just tune for the least ghosting possible


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I also get a better picture with RG59 made by Belden, than RG6 which got popular because of Sat. Stay away from any coax sold by Radio Shack as it has a very high signal loss compared to Belden. The longer the run the better it is to use good coax cable IMHO.


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Uh, Hugh, lots of the RG-6 that Radio Shack sells IS Belden cable. You just need to be careful which cable you buy. Do a bit of research.


In a perfect environment, 300 ohm twinlead has the least amount of signal loss, but you need standoffs to keep it away from your mast (and any other metal) and definitely keep it away from any A/C wiring. Shielded coax is much more forgiving (virtually immune to RFI), albeit with higher losses. You can overcome that with a signal pre-amp if you are in a fringe area. And if you ever get a satellite dish in the future, coax is a must - the signal levels off the LNBs on the dish are really low level. You don't get much gain from an 18" or 24" dish...


IMHO, use RG-59 only if it's a short run and you need to run through tight spots that would be impossible with thicker RG-6U cable.


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Jon Gauthier

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RG-59 will attenuate the high freq signals

RG-6 has a flatter response




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Discussion Starter · #9 ·
thanks for all the input, on using 300ohm twin lead, how much distance is required from the metal objects, and how much from ac wiring??
 

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All RG-59 and RG-6 are not created equal (i.e. RG-6 quad shield). RG-6 is necessary for Cable & Satellite, but not required for off air reception. Many RG-59's work just fine with off air reception. RG-59 is particularly not suited for Cable and Satellite since the center conductor is too thin, and the shilding is inadequate for the task. In addition, RG-59 "acts" like an antenna and picks up stray signals which is unsuitable for cable & Satellite. In addition, you can do much longer runs with predictable results with RG-6. Stray signals picked up from RG-59 when used for off air is not a disadvantage. Want even longer runs? Consider RG-11.
 

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The size (RG59, 6, 11) and the shielding (About 20% to near 100%) are completely independant specifications. The size determines the loss, the shielding determines the ability to reject outside signals.


RG59 is fine for satelite and cable IF the shielding is high enough and the distance is short enough! At 1GHz RG59 loses ~7.9 dB, RG6 ~6.4 dB and RG11 4.2 dB per hundred feet.


Most important point, the cheaper the coax usually means less shielding!


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