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Unregistered guest | Hello. We got a Sony with built in HDTV receiver about 2 months ago. I just grabbed a 150 mile antenna from my brother who still had one up in his attic and it's huge and like brand new. When I went to Radio Shack, they only had 100' of 2 lead 300 ohm antenna cable, which I purchased, along with a 15-1253 75 - 300 ohm transformer for 4 bucks. I think I initally read to use 75 ohm cable from the antennae to the TV, but all the 75 ohm at R.S. had coax connectors on the ends. Will the flat 300 ohm 2 lead suffice for our OTA needs? Does the antennae have to be in our attic or will it work in the garage? And is that the transformer we need? Thanks in advance |
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Bronze Member Username: MvanmeterKY USA Post Number: 21 Registered: Jan-06 | wow, this takes me back 30 years - to the wild and wooly days prior to cable and satelite saturation. 300 ohm twinline is almost "lossless", BUT it requires specific installation. Because it is not shielded like coax, it must be run in a manner that keeps it several inchs away from metal. On antenna installations of yester-year, you used stand-offs every several feet on the mast and around any metal, like gutters, when you ran the downlead into the house. Older TV's actually had two screw connectors for twinlead, but now all new TV's only have a 75 ohm coax connector. The downside to twinlead is that it is more prone to interference than shielded coax. A long run of 300 ohm twinlead is really an extension of your antenna and can "receive" additional interference if you live in an electrically "noisey" location. So, you mount your antenna in the best position in your garage (should work unless you have a bunch on fluorescent lamps - they can create a lot of interference)- point it towards the broadcaster ( www.antennaweb.org ) - connect the 300 ohm twin lead directly to the two screw-down connection points - carefully run the twinlead to the TV and then use a 300 ohm to 75 ohm converter to connect to the screw type F connector on the back of the set. If you have multiple broadcasters in different locations, you may want to consider mast mounting outside with a rotor to swing the antenna. But unless you have a friend who has experience with masts, guying, grounding, etc. it is not really a beginners project. |
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SonyTony Unregistered guest | I'd prefer to use the 75 ohm if it's better then the 300ohm. Especially if I won't have to worry about coming in contact with metal and messing up the signal. I say this b/c the 300 ohm yielded no digital channels last night. Could using all of the 100' of 300 ohm twin lead, when I only need 20' of it be the cause? Thanks. |
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SonyTony Unregistered guest | I'd prefer to use the 75 ohm if it's better then the 300ohm. Especially if I won't have to worry about coming in contact with metal and messing up the signal. I say this b/c the 300 ohm yielded no digital channels last night. Could using all of the 100' of 300 ohm twin lead, when I only need 20' of it be the cause? Thanks. |
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Bronze Member Username: MvanmeterKY USA Post Number: 22 Registered: Jan-06 | you do not want to leave the twinlead coiled up to take up the excess. Use only what you need. If you change to 75 ohm coax, you will need a different 300 to 75 ohm converter, one which attaches at the antenna terminals. But, if you were not getting any signal with the twinlead, you probably won't get anything better with coax. Was the antenna pointed in the right direction? Un-roll all of the twinlead and have someone hold the antenna up out in the yard, or hang it from a tree, pointed at the broadcaster and see if your tuner scan will pick up some stations. It is possible you are in a low signal area, in which case, only antenna height and correct pointing will help. |
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SonyTony Unregistered guest | Thanks. As I had mentioned, there was at least 50 extra feet of coiled twin lead by the TV. If I'm gonna eventually run it from the attic outside and then back inside to the TV room, I'd rather use the 75 ohm coax. Hence, I didn't want to unroll the 300 ohm since I will be returning it to R. Shack. Being less then 30 miles from NYC in NJ, I'd assume we should be able to pick up at least some of those local digital signals(especially PBS which is green on antennaweb)? I'm gonna install the antenna in the attic and give it a whirl. The roof/insulation shouldn't have a negative impact on the signal not being picked up correct? Thanks again. |