Cable and Digital to Analog Converter Box use

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Author	Message
jpm	# Posted: 28 May 2008 15:29 I just bought a digital to analog TV converter to use just in case I need it in the future. I now pay for a Time Warner NY DVR connected to my main living room TV. I also have two other TV sets (non digital) connected to the cable BEFORE it goes to the DVR. I get a variety of mostly network stations on those TVs. I guess the cable line now carries digital and analog signals. Experimentally I hooked up the converter box to an antenna and the box to RF input of a TV and got very good off-air and extra network converted digital signals. I then experimentally connected the Time Warner cable to the converter, and the converter to a TV, but then got no signal at all. This surprised me because I thought since the T-M cable is normally connected to the TV RF input, the TM cable would be carrying an RF signal. If so, the converter box should be able to see a T-W RF signal and process it. But it does not. Any ideas why not? Thanks. Joe
helpdeskguy	# Posted: 28 May 2008 15:52 it has to do with off-air and cable frequencys. the digital to analog converters are for people who pick up off-air signals with rabbit ears or some homemade anntena like a paper clip. lol , someone who has cable would have no need of a converter since their signal comes from the cable company. and i would suspect that the tuner in your converter is not capable of processing the cable company frequency's or more likely that they are filtered out. it explains why ch 19 off-air is a different ch # with the cable company. ch.19 off-air is broadcast around 503Mhz while the cable company here which is Insight sends ch.19 at 151.25Mhz.
jpm	# Posted: 29 May 2008 09:28 Hi Guy Thanks for your info. You seem to suggest that the Converter is designed to prevent seeing the signal from the cable company input. But if that signal is a standard RF signal (just like transmitted over the air and not yet processed to produce video and audio) which my analog TV can recognize, why can't the Converter also recognize the cable RF? Put another way, is the cable RF exactly like the over-the-air RF? Anyway, I'm hoping I can still use the direct to TV T-W cable to older spare TVs in the future without renting more boxes from the cable company. It's already costing over $100 a month for TV, DVR and Broadband.....since I'm retired, I want to hold down expenses! Thanks again for your advise. Joe
helpdeskguy	# Posted: 29 May 2008 10:16 both off-air and cable are radio frequencys just transmitted at different Mhz. i believe it has to do with the tuner in the converter, since the cable company has certain rights over their signal, it would be illegal for the company that made the converter to unscramble the cable companys channels. but no need to worry your analog tvs will work just fine with time warner cable hooked to them. basically if your a cable customer you dont need to worry about the digital switchover.
jpm	# Posted: 29 May 2008 12:34 Thanks for the feedback. I'm just concerned that Time Warner will switch to all digital signals in the future which my older analog TVs won't recognize. I just don't trust those rascals! : > )
antennaguy	# Posted: 29 May 2008 13:09 There are many converter boxes on the market, with more coming. As with any new technology, their quality, efficiency and price vary considerably. So the selection of a converter box will be an important variable to desired digital reception. But an even larger variable is the choice of the right digital antenna. Most TV consumers think of antennas as low-tech devices, but there is more behind some of the newer antenna designs than just bent metal and plastic. Many of the TV antenna designs on the market today, such as the Yagi and rabbit ears have technology roots going back 30 to 50 years or more. The switch to digital broadcasts however is bringing consumers back to Off-Air reception and the increasing sales are providing the motivation and investments necessary to develop new models and new technology. The fact that most designs on the market now were developed prior to the advent of much of the computer technology, software and algorithms in common use today, left open numerous avenues to improve upon tried and true designs and develop new ones. Additionally, recent regulations and standards are opening new doors for antenna engineers to develop smaller antennas with improved performance and aesthetics. The correct antenna, installed and aimed properly (considering obstructions) will receive desired local stations it's aimed at up to 70 miles or more, including multi-cast programming and several in HD, almost completely uncompressed, not necessarily available from cable or satellite. Some viewers may even be able to receive some or all of available out-of-town channels, carrying blacked out sports programs or network broadcasts not available in home towns. As an added benefit, an OTA antenna provides reception for second sets in homes not wired for whole-house signal distribution. While cable and satellite program providers will continue to serve the great majority of homes as the primary signal source, missing HD local reception, compression issues, higher costs, billing add-ons, service outages, contact difficulties, in-home service waits and no shows have left many of these subscribers looking to OTA antennas as alternatives and backup. Depending on the level of desire to receive an excellent digital picture and multiple broadcast signals, considering the investment in TV entertainment already made by many viewers, they should consider up-grading to a new Digital Off-Air Antennas.
JPM	# Posted: 29 May 2008 16:45 Good point about the quality of the digital signal even now available over the air (OTA). I have my 40 year old standard roof mounted antenna connected to my 46" Sony digital XBR LCD TV (in addition to cable). I did this because the antenna wire was still there and was easily added to the new Sony. The quality of OTA image is excellent, especially the new digital channels being broadcast by the networks. Of course I watch the cable signal, but have the good old antenna ready if the cable goes out.
Anonymous	# Posted: 27 Jun 2008 11:16 Just a quick thought on the ditigal to analog box. It seem that the box is amplied and I get lots of channels. It there any way to disable the down conversion so I can get digital (& HD) to my HDTV?
helpdeskguy	# Posted: 27 Jun 2008 13:17 not sure what you mean about about the down conversion? but an HD antenna should be all you need to get both digital and HD channels on your HD tv. you can probably find one at radio shack or best buy , i personally like the terk antennas. you can go to antennaweb.org for info on pointing your hd or digital antenna
catvjbs Member	# Posted: 29 Jun 2008 04:17 OK let's see how simple I can keep this... You say standard RF but there is no such thing any more. Not all digital is the same. In cable we use what we call QAM to or Quadrature amplitude modulation to modulate information from several sources onto a digital channel and there is more than one QAM they are 16-QAM, 64-QAM, 128-QAM and 256-QAM. A cable company can use any of these. So in short you're off air digital box is not compatible. But for a more technical explanation here is what I went to school to learn and it just go's to show we are not the dummies Verizon makes us out to be on TV LOL ... http://en.wikipedia.org/wiki/Quadrature_amplitude_ modulation

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