Convert coax cable to HDMI? Yes, only with DTV tuner.

If your LCD has a QAM tuner, you need to perform a digital scan to find the unencrypted DT (HD) channels that may be available from your cableco. Does your set have a QAM tuner? It may just have an analog NTSC/digital ATSC tuner. What model is it?

I believe at least some HD Tuners has QAM input and HDMI output (for those early adopters or those who bought an "HD Monitor". But then you will have to re-run an HDMI cable to your kitchen. Maybe it is your TV's fault of having a poor QAM tuner. In that case, the solution is much cheaper.

I'm pretty sure that HDMI can't carry multiple channels so you'd need something to select a channel and send it over HDMI. Like a cable box.

The internal QAM tuner is basically the same as any external QAM tuner that you could purchase. There will not be a major quality difference in using an external QAM tuner over the one integrated into your set. Your internal QAM tuner, if tuned to an HD channel, is fully capable of providing full HD. On a 19 inch screen, it should look fantastic. I suspect, you either have not scanned correctly, or you LCD is not setup properly. What channel is 84.2 or 84.7? Maybe they are just digital and not HD channels. What model LCD do you have?

As for your request in the last paragraph, no such thing. I don't think you have a clear understanding of the issue, which leads me to believe that your problem can be solved with a little discussion and explanation.

[quote=gerst003;12899873]The TV has a QAM tuner and I was able to find the channels, i.e. 84.2.
QUOTE]

Just because your QM digital tuner is receiving a digital signal does not mean that it is a HD digital channel. All HD is digital but all digital is not HD.
The networks nomally only transmit HD resolution over the xx-1 digital sub channel and transmit SD resolution programs over their xx-2 or xx-3 sub channels since they don't have the bandwidth available to trasnsmit more then one HD channel.

There is no such device that does what you are asking, nor will there ever be. The coax cable is carrying a digital signal for QAM stations. The tuner breaks it down into audio and video and sends it to the appropriate places. HDMI is just another form of carrying audio and video on the same cable. It can carry higher quality, uncompressed digital signals. But it cannot improve the quality of the signal input into it. The output signal, regardless of cable type, can only be as good as the input signal, which in this case is coax cable.

I agree with everyone else here that the stations you are seeing are being broadcast in digital, but not HD. With my QAM tuner I get at least 50 digital stations including some VOD channels, but only 5 of them ever have HD content and even then it is only if the TV show was recorded in HD, which is probably only 1/3 of the programs broadcast.

This is a total noob question (my apologies) but this thread seemed as good as any (short of starting a new one), so here goes:

How is it that HD can be carried through coax from an antenna (OTA), from cable (QAM or pay HD), or from a satellite dish to an HD Receiver, yet I have seen numerous sources (online "basics", news articles, "HD for Dummies"-type things, etc.) that say that HD signal can only be carried by HDMI, DVI, and component cables? In fact, I think I read one place that said coax can only carry 480i?

Obviously HD signals can be carried by standard coax, because all three sources (OTA, cable, satellite) use it. So what is "bad" about coax, that it is not used to go from the STB to the TV input?

I'm assuming that these "info experts" don't list it as a type of cable that can "carry HD" because you never see it used between the STB and the TV?

I'm sure this was explained somewhere previously within this forum, but there's so much info here that it's daunting to find. If it's easier than retyping, just point me to the right thread. Again, my apologies for such a noob question.

Thanks!

The signal coming in via coax cable be it OTA, sat or cable is compressed, it's then uncompressed in the cable box/sat tuner/OTA tuner and is passed to the display in uncompressed format.

Compressed OTA is typically around 14 to 18 MB's per sec depending on how the channel is set up by the station, uncompressed 1080i is about 800 MB's per sec.

In the case of this thread the signal is passed compressed into the set and uncompressed by the internal tuner for display.

Just how long of a distance are you runing your coax and how are you connecting into the cable system?
What exactly does your poor picture quality look like?
How large is the LCD screen?
What type of coax are you using? (RG-6?)

Coax cable can send QAM signals a whole lot farther than HDMI can send a video stream. Coax is the way it's commonly done.
It sounds like you have a problem with one of three things:

The way you split the cable signal at your starting point.
Length of cable
The type of cable you used
The tuner in your LCD TV

It would be easy enough to check the tuner by temporarily moving the TV to a cable outlet that you know is in working order.

If you have a low signal strength because of splitters or a long length of cable, a cable signal amplifier at the source makes sense.

It would be possible to use a HD QAM tuner, a high grade HDMI cable, and a RF remote to do things (almost) like you originally described (up to about 35' max.), but you would be spending maybe $400 on Rube Goldberg fix instead of address the problem.

I thought that OTA HD was supposed to be a little "better" than cable or satellite HD because it was not compressed (I know I read that somewhere)? Or is it just less compressed than cable/satellite, but still compressed?

The latter. Well, *sometimes*; some cable providers will recompress the stream, or do rateshaping on the bitstream, to get it to fit into a QAM channel with a couple (or more) other streams at the same time. Some do not. It depends on the provider, and the location (different locations, even those owned by the same provider, often do things *very* differently). They're all still encoded using MPEG-2 at either 720p (1280x720, 16x9, 60fps progressive) or 1080i (1920x1080, 16x9, 30fps interlaced), the variation is in the encoding process.

Edit: Or 480i, but for HD, it's one of the above; also, satellite providers reencode and tend to cut the resolution of the video, hence the references you'll see peppered around to "HD-lite" (usually like 1280x1080i or something along those lines).

Directv is known to cut the resolution on their older MPEG2 compressed 1080i channels due to lack of bandwidth on the older sats, no proof if they are doing it with their newer MPEG4 channels yet. The reports in general is the PQ is similar or equal to OTA feeds for the HD local channels.

hanging an lcd on wall I have coaxial cable where tv will go and coaxial where
hd box will go, tv and cable box will be about 10 feet away from each other. i dont want to see the hdmi cable. is thier some sort of converter i could buy to make it look clean.

Gefen makes a new product that distributes HDMI over a single coax using a sender and receiver combo. It even works through passive splitters! Best bet is to ask a friend if they know any local custom installers. They could probably custom install an HDMI cable for less than the combo.

OK, here's a reason why I need to convert coaxial cable TV in to HDMI: I have an HD TV that I primarily use as an external monitor for my laptop. One day I did something stupid and went to plug the coaxial cable in to the TV. But I forgot to turn it off. Sparks flew.

After cursing myself for 10 minutes I powered everything down and went to plug in the cable to the TV. Then I plugged the TV in to the power strip. The power strip wasn't even on and it blew the fuse at the breaker box. What did I do? I tried it again. It did the same thing.

So I bought a power strip that grounds cable and also has a "grounded" light indicator. The outlet wasn't grounded either.

Until I can get an electrician to do some work in "this old house," I have thought of getting a cable box that has a coaxial input and an HDMI output. I still use the VGA input from my computer and it works fine.

Thanks for reading my long, clutzy story.

extensive online searching continually brought me to this post.

You may have an electrical current in your cable. You need to get a qualified electrician to examine your problem before someone is injured or killed. Attaching a coaxial cable to a TV that is on is probably not a great idea but should NOT result in sparks.

Supposedly OTA is less compressed than cable/sat TV.
But compression is not the real problem.
The problem (or cause of PQ loss) is that the video compression is lossy.
You can use compression to reduce the size of data files and programs on your PC, but when you uncompress those ZIP files, you get back the original data and files. That's lossless compression.

Yeah, sparks indicate something bad, unless it was just static electricity.
If that's the case, you need to learn to ground yourself and discharge the static buildup before touching electronics.

"Coax" is just short for "coaxial cable", and there are many types. Even the oft-mentioned "RG-6" is not that specific, and not all RG-6U are suitable for wiring for a TV antenna.

By "coax" you probably mean something like RG-6 or RG-59, which are stiff (difficult to handle and should not be bent/kinked), intended to carry RF (radio frequency, but that includes TV) signals of very low voltage (microvolts or 0.000001 volts), and have large bandwidth (up to 3 gigaHertz). The other cables used between STB and TV probably have coaxial construction, but are much more flexible, only have bandwidths of ten or twenty megaHertz, and the signals carried are in the 1 to 5 volt range.

It's not the cable type per se, it's the type of signal that it carries. Component-video cables are coaxial, too.

The signal that comes in from an OTA antenna, or cable company, or satellite dish, carries video signals (analog and/or digital) for many channels simultaneously, which are modulated onto radio-frequency (UHF or VHF) carrier signals of different frequencies.

A VCR or digital TV converter box that uses a coaxial connection to the TV, has to take a digital TV signal that it's already extracted from OTA/cable/sat, convert it to analog (NTSC), and modulate it onto a carrier signal for either channel 3 or 4. Then the TV has to de-modulate it just like it does if it is receiving channel 3 or 4 directly from OTA/cable. The extra modulation and de-modulation steps impact the picture quality of the video.

If the TV can tune digital (ATSC) channels, then in principle, we could avoid the hit on picture quality by modulating the digital signal directly onto channel 3/4 so it looks just like a digital OTA (ATSC) or cable (QAM) signal. But consumer units don't do this, probably because of the extra cost of the modulator circuits and the fact that all HD-capable displays have either component-video or HDMI inputs anyway, and not all of them have ATSC or QAM tuners.

Sorry for the bump, but I have a related question.

I just recently got an antenna etc hookup. I also have a receiver, speakers, etc. How can I get my antenna signal to go through my receiver so I can listen to it on my good speakers instead of the tv ones (as well as saving a cable going to the tv)? I'd rather a way to go to HDMI to preserve the HD stations I'm getting.

Actually your question has absolutely nothing to do with this topic...

Regardless though what it sounds like is you think an antenna into your AVR (receiver) will give you OTA station audio and that won't happen...You need to run a connection from the TV audio out (if it has one) to your AVR and listen to it that way...You don't explain what "etc" is...

A new topic would be better...

It is related, in that I'm wanting a way to convert coaxial into hdmi, which is what the topic is titled...

What I'm aiming for is to keep my cable clutter as minimal as possible, to use as few inputs on the tv as possible (I hate switching them, takes ages as you can't directly choose one), and to be able to use my nice speakers for the audio rather than the TVs.

The ideal solution for this would be to somehow convert the coaxial into hdmi, plug that into the receiver, and the existing hdmi into the tv will pass the video (no video input switching on the tv required), and the good speakers will play the audio.

Otherwise, I'll have to have the coaxial going to the tv (involving a video input switch), and use the tv speakers, OR, run audio cables back from the tv (even more cables, and adding an audio input switch) to the receiver...

The "etc" doesn't really matter, it referred to my dvd player, computer hookups, & game systems that're hooked into the receiver/tv, all of which play over the good speakers.

Well this thread is about cable and not an antenna but I'm not going to argue with you...You really should be starting a different thread...

Now I know what you want to do and as I have already answered you...and you even repeated what I said...The only other way is to get a set top box with ATSC tuner that your antenna connects to and outputs via HDMI...And no there are no HDMI coupon eligible STB's...You will have to find a HDTV STB like a Samsung or LG for example to do what you want and just use your TV as a monitor...And while there are some HDMI equipped STB most you will find are DVI/component...

Or depending on the TV you have, it may have an optical digital output, which you can then connect to an optical input on your receiver to get the raw Dolby Digital bitstream. Unfortunately you haven't mentioned specifically what set you have. However, as has been mentioned, you don't want to (and can't) "convert" what comes off your antenna coax to HDMI other than with a separate tuner box - and you wouldn't really want to. It's probably unnecessary. Check your TV's manual, many recent models have an optical digital out for this purpose.

It is a little like asking how to convert your cable TV cable into a telephone cable. Sure you can connect your telephone to your cable, if you have a cable modem and a VOIP (voice-over-IP) converter, but that's really veering well away from the question as stated.

The short answer is you can't simply (passively) change one cable into the other; they carry drastically different kinds of signals.

One way, as noted, is to use the tuner in the HDTV (fed by the coax cable) and run the digital audio back to the AV receiver (with a single digital optical or coax cable). Note that the coax going into the HDTV is carrying either an over-the-air or cable signal, filled with a number of channels all with digital video and multichannel digital audio, while the digital audio optical or coax cable that goes from the HDTV to the AV Receiver carries just a single digital audio signal for the one channel the HDTV is tuned to.

Otherwise, as noted, get an outboard DTV tuner with HDMI (& QAM for cable, if needed), and run all HDMI sources into the AV Receiver, which will be used to switch all sources, audio and video. The selected video will go via HDMI to the HDTV, and the selected audio will play back through the speakers connected to the AV Receiver.

I think I have the same problem as the original question. Please excuse my laymen question.

I just bought a new Samsung 32" LCD, 720p. It is connected to the cable wire coming out of the wall. The HD channels are crisp (not a problem), but all the other digital channels (gold, TNT, USA, Nick, etc), are not clear at all. Cannot see clear detail in the people or scenery - very blurry. I connect my old 13" tub TV to this connection, and it comes out much clearer. I was on another forum and most of the responses were to get a cable box. Do all LCD TVs need a cable box to get a decent (not great, but decent) pic from the regular digital stations?

I have another new samsung 26" lcd, that an AV tech installed and I swear the reg digital pics were really good until I re-ran the auto-channel because some of the stations were not set up. Now it is as bad as the 32" lcd (we just took it out of the box and plug and played). I have already gone through the numerous menu options for contract, sharpness, etc. and overall still does not give a good picture. Any help is appreciated. thank.