Wadek's tv problems

I sympathise. Some channels in my area have switched to digital, and some have not. It was theorized that after the switch they would pump more power to the digital. Some, like channel 7 and 9 out of Denver, have apparently reduced the power, as I can no longer pick them up. Before, when they were broadcasting both, I could pick them up in both analog and digital. Go figure. Most other channels are OK. I will need to get an amplifier if I want to see them, but not sure if it is worth the effort. I will probably wait until June 17 before deciding (in case they boost their power then).

You must have a digital converter box to use with a good UHF antennae.

Be patient. The switch to DTV has not gone well and stations are working on improvements. In particular, you should probably now be seeing poor sound synch, and dropouts when the wind blows. It's not clear how much the stations can do, but try raising/lowering your antenna perhaps 50 cm each way to see if that helps. Some consumer groups are advocaring going back to outside antennas, though I think that might be extreme. Try to make do a few months. Our signals have improved for some stations, not for others.

OP "I used to get good reception on a attic antennae with a small ampflier but since I purchased my new Sony, the reception is poor. Previously I was told that if my antennae brought me a good analog picture it would probably get me a good DTV picture, but this is proving to not be the case"

It seems that you guys are having the same issues we in Australia have with Digital TV. Its to be expected that comparing the robust analogue signal with the fragile digital signal you are not going to get the same performance.

You will need to put a mast head amplifier onto your antenna system to improve the signal sufficiently enough to give comparable performance.

However that said any multipath signal interference will dramatically affect the signal. This leads to there being "artifacts"* in the picture or the audio chopping out.

Rule of thumb regards DTV antenna systems is if you used "Rabbits Ears" antenna you now need a "Metro" external antenna, if you used a Metro antenna you need to use a Fringe one now. If you used a Fringe then your gonna have to stack them and increase the amplification.

The only benefit I can garner in the whole DTV is better than Analogue is that they can cram more stations in a given bit of spectrum. As for us mug punters there is no advantage only cost.

* Artifacts are blocks of pixels that are not the intended as part of the picture. Usually due to corruption of the signal.

I have no experience with the new digital standards yet, but I was of the impression that digital systems will have a "go/no go" level for the signal strength, below which they will not let a signal through because the bit error rate, etc., is too high. Analog, on the other hand, simply passes ANY signal through, relying on the human perception of picture quality to decided whether the signal is good enough or can't be viewed. That is the theory.

Since you have had quite a bit of real world experience with broadcast digital TV (as opposed to digital cable), would you say that the above is true, or is it more complex than that?

Thanks,

Kos

I'm not sure, but the results of my message seem to be saying,"hang on , it will get better". The nagging part is when on digital, having the sound disappear and sometimes having the picture freeze. According to some info that I have received my problem is not unique, it is the results of the media just not being prepared for this new cycle.

Thanks for your comment/

Wadek

"The only benefit I can garner in the whole DTV is better than Analogue is that they can cram more stations in a given bit of spectrum"

The advantage I can see is absolutely no snow (i.e. excellent picture). The problem when signal is weak is pixelization (sp?) and worse yet, the sound cutting out or missing entirely. With analog the sound was FM, and was always good even when there was a lot of snow in the picture.

The main problem is that the channel spacing is so tight that they can never send an HD picture.....

Assuming you are talking about DVB(T), then a DVB(T) Antenna with a built in amp costs about €30 here with power supply. That's a good one with 20dB gain......you only need to know if your TV (or set top box) can supply the 5 volts.

(By the way, if you are using a normal analog antenna, make sure that the DVB(T) 5 volts is switched off!!)

Mounted outside of the building on the side where the signals come from will probably fix all your problems......that's exactly what we do here.

Test the direction of your local service before fixing in place, using a long pole or similar, we find here that the digital signal is more "directional" than the old analog was.....also, the house construction also reduces the signal levels significantly..... mounting higher is usually better.....trees also reduce signal strength, so if you are already close to minimum......remember that trees continue to grow too....

Hi Wadek

I don't know if your existing analogue signal is in the VHF band or UHF, where DBT is.

You should have quality coax (Quad shield) F type connectors and use it for fly leads also. A suitable gain UHF antennae properly aligned is essential. Older coax for VHF only has too much attenuation at digital (UHF) frequencies.

A mast head ampilifier will only amplify noise if that is all it is getting from the antennae.

Good luck

Steve

GA for a good and important point...

Having forked out the dollars on a quality HDTV, and comparing the quality of the vision between HDTV, SD and Analogue, there ain't much in it. Certainly not enough to warrant replacing all the tv's in the house, I'll just get HDTV capable set top boxes and be done with it. That's only because they have occasionally different programming on the HDTV channels here.

I'm lucky that we live are near the translators, and can receive an adequate signal most of the time. You tend to be limited in rental accommodation as to what you can do to improve things. Landlords hate spending money, even when its your own.

Here in Australia they have been opening up the UHF band to DTV, which is easy because we only have 5 national TV stations, and one public broadcaster in each of the capital cities. Most of our DTV push has been to migrate the TV stations in the capital cities from VHF to UHF. With the promise of the stations being able to expand their output with additional "channels". In the regional centres like where I live, (Central Coast) it has been ok, but we have all had to upgrade our antenna systems to cope. All new installations get fringe range 11 element Yagi style antennas with mast head amplifiers and the quad sheilded coax. If the house is in the valley, then they have to use tall guyed masts but that has always been the case. The only other way around it is to go with Sat/cable tv, one of the major suppliers here rebroadcasts the signals on their service but that's at a cost.

Wadek, I suspect that you will have to wait till they get the DTV sorted in your area before you can fully fault find. However upgrading your home installation with the quad sheiled coax and uprated signal splitters (you don't mention if you have more than one tv attatched)and terminations is a start. Plan for an external Antenna, if there are building code issues then you'll need to get those addressed now.

Cheers

Perry

You imply (if I understood you correctly) that you get HDTV broadcasts from Terrestrial transmitters in Australia......

If true, then Australia has a different system to most of the rest of the westernized world with DVB(T), which cannot send HDTV via terrestrial transmitters..........only with Sat and cable.....

Yes we get HDTV via terrestrial transmitters, and most likely its a home brew (Australian) specification. That said all of the TV's with digital tuners are usually capable of receiving both SD and HD signals, while set top boxes and DVRs with digital tuners are usually SD with the upper spec models being HD compatible.

Attached is a link to an independent commentator on the "local" Australian DTV saga, which will give you more answers.

http://www.digitaltvfacts.net.au/dtv2html/intro.htm

and something else to reference it to.

http://www.cnet.com.au/hd-tv-resolution-explained-339271051.htm

Cheers

Perry

Good links, thanks.

It would appear that HD in Australia is little different to the rest of the Westernized countries I mentioned earlier....

Australia tends to try to do its own thing from time to time, they did the same with HF CB radio by legislating that only 18 channel radios (with one of the channels not part of the international cb band plan) were legal, at a time when the market was already full of the 23 channel radios. Then they eventually relented and adopted the 40 channel HF CB radio band plan. Creating an instant headache for importers and retailers alike. Not to mention grumpy users who spent money on radios that were now obsolete.

Digital TV will be the same.

I'm waiting to see what a hash they are going to make of digital radio. Which is an answer to a question nobody asked.

This does bring up one key problem that Wadek and many new posters have. Many technical questions can only be accurately answered if we know where you are. Wadek, add to your user profile some location information.