 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion GroupsElectronicsBasicsRepairDesignCADComponentsEquipmentElectrical Engineering ElectronicsKB.com Contact UsLink To UsSearch & Site Map |
Electronics Forum / Electronics / August 2007can digital get picture if analog TV is weak?
I have analogue telly at the moment. I use three antennae for VHF low, VHF high, and UHF going into a triplexer. Thus I can adjust each one separately. The VHF high (for 7, 9, and 10) is the problem, probably because the channel 10 transmitter is in a different direction to 7 and 9. I have moved the antenna all over the place, but can't get a good picture on all three. After last attempt I have channel 7 the noisiest, and if it rains, the picture drops back to black and white. I can't raise the anntenna any higher. So I wonder will going digital help? If the signal is weak and borderline for analogue TV, will a digital box pull out anything? On Aug 3, 4:36 pm, u235b...@ml1.net wrote: > I have analogue telly at the moment. I use three > antennae for VHF low, VHF high, and UHF going [quoted text clipped - 10 lines] > If the signal is weak and borderline for analogue > TV, will a digital box pull out anything? Impossible to say, it's always a case-by-case basis. But generally you need a decent analog reception to get digital on your existing antenna. Look here to see where your digital transmitters are located: http://www.dba.org.au/index.asp?sectionID=22 Sounds like it's time you upgraded your antenna and system installation anyway. You might even be able to get away with a single digital antenna. Once you get digital you won't go back. Dave. > On Aug 3, 4:36 pm, u235b...@ml1.net wrote: >> I have analogue telly at the moment. I use three >> antennae for VHF low, VHF high, and UHF going >> into a triplexer. Thus I can adjust each one >> separately. The VHF high (for 7, 9, and 10) >> is the problem, *** that's because 7 & 9 are UHF probably because the channel 10 >> transmitter is in a different direction to 7 and 9. >> I have moved the antenna all over the place, but [quoted text clipped - 9 lines] > need a decent analog reception to get digital on your existing > antenna. *** It does not follow, that simply because you have a lousy analogue signal, that a digital signal will be the same. In some cases a non-existant analogue signal will result in a digital signal. With digital there is no such thing a s good or bad, You ether have a signal or you don't. > Look here to see where your digital transmitters are located: > http://www.dba.org.au/index.asp?sectionID=22 > > Sounds like it's time you upgraded your antenna and system > installation anyway. You might even be able to get away with a single > digital antenna. *** Define "Digital" antenna. They don't exist.. > Once you get digital you won't go back. > Dave *** why would you want too ?????? > With digital there is no such thing a s good or bad, You ether > have a signal or you don't. Not quite true. It is correct that a "weaker" digital signal will result in intermittant or sometimes non-existant viewing. However a too strong signal can also cause reception problems. Of course, this doesn't happen very often, but it certainly has happened here in Australia when people are close to the transmitters and still insist on using high gain antennas. I'm guessing it comes down to the AGC range of the receiver at the high end of the scale, likely their analogue receiver was obviously better at handling high signals than their set top box or whatever.  SignatureLinux Registered User # 302622 <http://counter.li.org> >> With digital there is no such thing a s good or bad, You ether >> have a signal or you don't. [quoted text clipped - 12 lines] > end of the scale, likely their analogue receiver was obviously better at > handling high signals than their set top box or whatever. I think your attempting to split hairs, and failing. FEC decides if the standard of the signal is reproducible. While I will agree with you in part about high gain antenna's it's still controlled by FEC, and this also makes masthead amps obsolete. Many people who had a high gain antenna, for analogue systems, retained that antenna, and in 99 cases out of a 100, it does the job. And some people will tell you, that it's imposable to have a "too" strong signal, it's also arguable , that modern Tuners are self regulating in that regard.. BUT unlike analogue, we have "Forward Error Correction " which examens the signal long before it reaches the Tuner, Would you not agree. bassett > And some people will tell you, that it's imposable to have a "too" > strong signal, it's also arguable , that modern Tuners are self > regulating in that regard.. BUT unlike analogue, we have "Forward > Error Correction " which examens the signal long before it reaches the > Tuner, Would you not agree. While FEC plays a part, if the front end is swamped, you're going to corrupt the signal to the point that FEC isn't going to have much of a chance to do anything. SignatureLinux Registered User # 302622 <http://counter.li.org> >> And some people will tell you, that it's imposable to have a "too" >> strong signal, it's also arguable , that modern Tuners are self [quoted text clipped - 5 lines] > corrupt the signal to the point that FEC isn't going to have much of a > chance to do anything. What you forgot to say, was that if and when the front end is swamped, [presumably with signal strength, or overload ?? ] the FEC will be unable to cope and simply shut down. After all that's what it's there for, and please remember we are using a 3/4 comfigeration not a 7/8, bassett Hi John, long time no see. Not since the old avtech days. > While I will agree with you in part about high gain antenna's it's > still controlled by FEC, and this also makes masthead amps [quoted text clipped - 10 lines] > Tuner, Would you not agree. > Maybe something has escaped me here, but I was under the distinct impression that the FEC operated on the data stream, implying the demodulated signal. That being so, how can it be "examine the signal long before it reaches the tuner"? So no I would not agree. > However a too strong signal can also cause reception problems. Of course, > this doesn't happen very often, but it certainly has happened here in [quoted text clipped - 4 lines] > of the scale, likely their analogue receiver was obviously better at handling > high signals than their set top box or whatever. I live in a strong signal area, and I always find the reverse to be true. MrT. > > On Aug 3, 4:36 pm, u235b...@ml1.net wrote: > >> I have analogue telly at the moment. I use three [quoted text clipped - 36 lines] > > *** Define "Digital" antenna. They don't exist.. A "digital" antenna is one designed only for the channels used by digital TV, and those *do* exist. Perhaps they should be called "digital band" or something to avoid the stupid semantic arguments. My "digital" antenna is is not only designed just for the digital channels, but it's a log-periodic design too which can give an improved signal and better noise immunity in some situations. Much smaller and nicer looking than my old "analog" band yagi antennas. Dave. > > > On Aug 3, 4:36 pm, u235b...@ml1.net wrote: > > >> I have analogue telly at the moment. I use three > > >> antennae for VHF low, VHF high, and UHF going > > >> into a triplexer. Thus I can adjust each one > > >> separately. The VHF high (for 7, 9, and 10) > > >> is the problem, There is simply no correlation between Analogue and Digital signals so the digital results depend on many other things than what your analogue signals are like. As a generalisation if you have a snowy analogue signal with ghosts then the probability is that you will get digital. The original poster does not say which city he is in but 7 and 10 analogue come from the same site in Sydney with 9 analogue from another site and ABC from the 3rd Gore Hill site. 9 digital comes from the same site as the 9 analogue signals while 7 and 10 digital come from the same site as the analogue at times and from the 9 site at others. ABC digital comes from the same site as the analogue channel 2 and SBS analogue comes from Gore Hill while the digital usually comes from the 7 10 site. As far as Basset's assertion that 7 and 9 are UHF thats patent rubbish. It will be instructive if the poster tells us which city he is in and then we may be able to give some real advise instead of the useless answers so far. <100246.2055@compuserve.com> wrote in message > There is simply no correlation between Analogue and Digital signals > so the digital results depend on many other things than what [quoted text clipped - 15 lines] > As far as Basset's assertion that 7 and 9 are UHF thats patent > rubbish. Most charming, I'm sure, I have a little 60inch tellie in the kennel, It has a three way tuner channels 7,.9, SBS are tuned via the UHF tuner, Channel 10 is VHFH and ABC is VHFL and the other thing you got incorrect is all my rubbish is patented. So hands up all those who invited this f.ck-wit, to answer. > It will be instructive if the poster tells us which city he is in and > then we may be able to give some real advise instead of the useless > answers so far. You of cause include your own answer, one would assume Next, bassett >> As far as Basset's assertion that 7 and 9 are UHF thats patent >> rubbish. [quoted text clipped - 5 lines] > and the other thing you got incorrect is all my rubbish is patented. > So hands up all those who invited this f.ck-wit, to answer. which means in your location you are tuning to UHF repeaters of 7 & 9. This may be the case in your location, and is the case in most of regional australia, but in every eastern capital (and possibly adelaide & perth but haven't checked), 7 & 9 are broadcast on channels 7 & 9 respectively which are located in the VHF-H band. In some locations where geographical conditions prevent reception on the main channels, repeater stations have been set up on UHF channels. They can't set up the repeaters on the main channel because it would cause interference. The actual frequencies used will vary depending on what channels are available in the location and depending on what channels are used by adjacent regional stations. >> It will be instructive if the poster tells us which city he is in and >> then we may be able to give some real advise instead of the useless [quoted text clipped - 3 lines] > Next, > bassett >>> As far as Basset's assertion that 7 and 9 are UHF thats patent >>> rubbish. [quoted text clipped - 11 lines] > haven't checked), 7 & 9 are broadcast on channels 7 & 9 respectively which > are located in the VHF-H band. FYI, Adelaide's main analogue transmitters (near Mt. Lofty) are all VHF, except for SBS which is UHF ch 28. The analog VHF is on channels 2, 7, 9, 10, but there are UHF repeaters in the CBD, mainly for those in the shadow of the hills. Digital is also VHF from Mt. Lofty, on channels 12, 6, 8 and 11 for ABC, Seven, Nine and Ten respectively. I think SBS digital is UHF like their analogue and the digital repeaters in the CBD are all UHF. > which means in your location you are tuning to UHF repeaters of 7 & 9. This > may be the case in your location, and is the case in most of regional > australia, but in every eastern capital (and possibly adelaide & perth but > haven't checked), 7 & 9 are broadcast on channels 7 & 9 respectively which > are located in the VHF-H band. Impossible while they are still transmitting analog signals on those frequencies. AFAIK, SEVEN transmits digital on ch6, NINE on ch8, TEN on ch11, and ABC on ch12 in most capital cities. MrT. > As a generalisation if you have a snowy analogue signal with > ghosts then the probability is that you will get digital.... ...... drop-outs. :-) MrT. >>> On Aug 3, 4:36 pm, u235b...@ml1.net wrote: >>>> I have analogue telly at the moment. I use three [quoted text clipped - 42 lines] > > Dave. A log periodic has lower gain than an equivalent sized Yagi. There is nothing that would make a log periodic better. Having excessive bandwidth is pointless. The only improvement I could see would be to have a loop antenna, maybe like a cubicle quad, for lower noise and slightly higher gain than a Yagi. Dorfus wrote: >> "David L. Jones" <altz...@gmail.com> wrote in A "digital" antenna is one >> designed only for the channels used by [quoted text clipped - 7 lines] >> >> Dave. Just perhaps you could provide a link to your "digital" antenna, then we can all evaluate it. bassett "bassett" > Just perhaps you could provide a link to your "digital" antenna, > then we can all evaluate it. ** Dave did that - about 2 weeks ago on " aus.electronics ". " Also, my "digital" antenna is a log-periodic type, like this one: http://www.australiandigitaltv.com/accessories/digitalantenna.htm Dave. " ....... Phil > wrote: >>> "David L. Jones" <altz...@gmail.com> wrote in A "digital" antenna is one [quoted text clipped - 12 lines] > then we can all evaluate it. > bassett It's all about syntax - of course there is no such thing as a digital antenna or a digital microphone for that matter but it is human nature, especially in Australia to shorthand the language even if it's technically wrong. Personally I like this charming Australian characteristic. A so called "digital antenna" is one that has been designed to receive those frequencies that are used in Australia for DTV.ie nothing below Ch6 (analog). Mine is a Fraccaro log periodic http://www.laceys.tv/secure/index.php as is my friend who has absolutely no analog reception regardless of antenna design array, well not unless he was willing to put up a 200 foot pole! The Fracarro pulls in 96% signal strength with similar quality on his Topfield 5000. And here I am a few suburbs away with perfect line of site with 100%. So this antenna must be doing something the others don't, all tried by a antenna specialist engineer (not Hills! etc) who did extensive measurements of signal strength and quality using a range of antenna designs. So as far as my friend is concerned he is not the least bit interested in the technical analysis just the excellent results he has achieved for a $50 antenna that is quite tiny, even the birds don't sit on it and another $150 for installation and new quad cable etc.. >> wrote: >>>> "David L. Jones" <altz...@gmail.com> wrote in A "digital" antenna is [quoted text clipped - 41 lines] > sit > on it and another $150 for installation and new quad cable etc.. Thanks Stu, your a lone voice in the wilderness. People are gulable when it comes to this sort of thing, Just say "digital" and the price goes up, The intrest intensifies, and people cue up to be ripped off. The link that Phil posted [Hi Phil] is a typicial example of the rip-off machine in action. About the only thing you might need is a better cableing system , In other words swap the cable for a length of RG 6, thats worth 30 cents a meter and people like Dick Smith sell for $3 a meter. Cos it's digital cable. and your away. bassett "bassett" "Stuart" >> A so called "digital antenna" is one that has been designed to receive >> those frequencies that are used in Australia for DTV.ie nothing below Ch6 [quoted text clipped - 7 lines] > The link that Phil posted [Hi Phil] is a typicial example of the > rip-off machine in action. ** The link I posted was for the EXACT SAME ANTENNA - you bloody half- wit !! http://www.australiandigitaltv.com/accessories/digitalantenna.htm ........ Phil > >> wrote: > >>>> "David L. Jones" <altz...@gmail.com> wrote in A "digital" antenna is [quoted text clipped - 43 lines] > > Thanks Stu, your a lone voice in the wilderness. Lone voice? I said that earlier in the thread: http://groups.google.com.au/group/aus.electronics/browse_frm/thread/77397d5268a1 0553/b39e6f3e6c5b435e?hl=en#b39e6f3e6c5b435e > People are gulable > when it comes to this sort of thing, Just say "digital" and the price > goes up, The intrest intensifies, and people cue up to be ripped > off. > The link that Phil posted [Hi Phil] is a typicial example of the > rip-off machine in action. The link Phil posted (which was my original link in an old thread) is the exact "digital band" antenna being talked about! It is *not* an example of "the rip-off machine in action", it is a log-periodic digital band antenna, designed just for the digital channels. Let me know your PayPal address so I can send you a dollar so you can buy yourself a clue. Dave. > Let me know your PayPal address so I can send you a dollar so you can > buy yourself a clue. Save your dollar, he wouldn't know where to buy one. MrT. >>> wrote: >>>>> "David L. Jones" <altz...@gmail.com> wrote in A "digital" antenna is [quoted text clipped - 55 lines] > sell for $3 a meter. Cos it's digital cable. and your away. > bassett Although as Bassett has said, there are a lot of rip-offs out there and certainly a lot of misinformation about digital antennae systems, there is some info which is correct. For example - Anyone from the good old analogue days (circa 1980's) will recall the Hill's Telray series VHF antennae. When I went across to digital very early in the piece my antenna system consisted of a Telray TL4, a Hills Band 4 UHF antenna (20 or more elements - can't recall the model number) and a diplexer hooking the two together, fed by double shielded coax similar but not the same as the current RG6. The combination worked quite well for analogue not withstanding the unfixable ghosting problems in my reception area. On purchasing a STB I noticed reception of ABC digital (VHF ch 12) was very flaky and the signal level almost down in the "red" compared to the other digital channels which were way up the other end of the scale. It turned out that after pulling up the specs on the TL4 that it performs very well to Ch11, where thereafter the gain of the antenna takes a steep dive. This along with the original diplexer really knocked the crap out of the signal level at those frequencies. Replacing the TL4 with a Hill's DY10 and upgrading the diplexer totally solved the problem. There is however a bit more to the story. Replacing the diplexer also meant replacing the short lengths of cable between the antennae and the diplexer with F connectors (replacing saddle clamp connections) and of course fitting the downlead with an F connector too. It is recognised within the industry that albeit the digital signal is relatively robust it isn't completely immune to interference. Whereas with analogue we put up with the odd bit of noise on the picture, digital can be affected to the point of significant pixilation and muting of the audio. This can be subjectively more annoying than watching a noisy analogue picture. Antenna downfeeds and distribution cables installed in close proximity to power cables, fluoro lighting and some other electrically "noisy" equipment can degrade the quality of the received digital signal leading to pixilation and in some cases muting of the audio. Using a good quality tri or quad shielded coax and sensible placement of the cable(s) in relationship to other electrical services can make all the difference to the quality of the signal the TV or STB receives. Unfortunately there are a lot of legacy analogue antenna systems out there. Some suitable for digital, some not. Blocks of flats with amplified distribution systems designed purely for analogue are typically a nightmare for digital as only the designated analogue channels are amplified and equalised, leaving the intervening digital channels with level and equalisation problems. Likewise there are some houses out there with a good old ch2, 7, 9 antenna with a 300 ohm balance ribbon feed. With the exception of SBS they are probably getting by with adequate analogue reception but lets face it, the antenna has probably seen 30+ years of life and is well and truly overdue for replacement. The sad part is the owner will be quite prepared to fork out $4k on a new plasma or LCD TV but won't spend a couple of hundred bucks getting the antenna system replaced. Cheers, Alan On Aug 7, 1:33 pm, "Alan Rutlidge" <don't_spam_me_rutli...@iinet.net.au> wrote: > It is recognised within the industry that albeit the digital signal is > relatively robust it isn't completely immune to interference. Whereas with [quoted text clipped - 8 lines] > relationship to other electrical services can make all the difference to the > quality of the signal the TV or STB receives. Unfortunately I'm still having issues with interference after trying all the usual recommendations: - replaced all my cabling to quad shield RG6 and F connectors, even from the wall outlet to the TV. - switched to a new higher gain antenna to get better signal strength - checked my mains earthing - connected the antenna to its own earth stake. - made sure the cabling was not near any other cables - and finally switched antenna's yet again to a log-periodic type (that reduced the number of drop-out's very significantly) But alas I still get the occasional drop-out due to some external influence (not local appliance switching in my house, although that does it too), and of course due to MrMurphy it's always right at a key point in a show. Losing the picture for a second is ok, but the audio pop is really annoying. But at least it's down to a very manageable level now. Dave. "David L. Jones" > Losing the picture for a second is ok, but the audio > pop is really annoying. ** Some STBs produce occasional huge audio pops ( like the TEAC DVB-300) while others are near silent when a burst interference causes the pic to freeze. However, an audio pop could be nothing to do with the STB but rather a result of the same RF burst getting into the audio earth wiring due to the existence of ground loops. Try installing an antenna isolator before the STB. ....... Phil > "David L. Jones" > [quoted text clipped - 4 lines] > while others are near silent when a burst interference causes the pic to > freeze. I've tried 3 different STB's and all are pretty much the same with the interference and the popping. Guess I didn't get lucky. > However, an audio pop could be nothing to do with the STB but rather a > result of the same RF burst getting into the audio earth wiring due to the > existence of ground loops. > > Try installing an antenna isolator before the STB. Will do, thanks Phil. A quick search doesn't turn up much though, know where I can get one? Thanks Dave. "David L. Jones" Phil Allison >> However, an audio pop could be nothing to do with the STB but rather a >> result of the same RF burst getting into the audio earth wiring due to [quoted text clipped - 5 lines] > Will do, thanks Phil. > A quick search doesn't turn up much though, know where I can get one? ** K-Mart used to sell 'em. Not impossible to wind your own iso-balun. ....... Phil > On Aug 7, 1:33 pm, "Alan Rutlidge" > <don't_spam_me_rutli...@iinet.net.au> wrote: [quoted text clipped - 36 lines] > > Dave. Albeit I think I've just about solved all my digital TV reception issues, it is still far from perfect. :-( AFAIK in Perth the digital transmitters are not running at full power (apparently to reduce interference) to older analogue sets and analogue VCRs with less than perfect tuners. When and if the analogue services are shut down the digital transmitters will be allowed to run at full power. This should improve the signal to noise ratio and hopefully resolve some reception problems. Having said that, too much signal level can be a problem as well. Attenuating the signal at the wall outlet will not only reduce the signal level to an acceptable one, but reduce the interfering noise by the same amount. The problem with RF is it isn't a totally predictable science. Take mobile phone coverage as an example. There are too many variables which influence the propagation of the signal to be totally sure of the outcome. Add external interferences (natural and man made) and you have a cocktail of situations which can lead to problems. And of course there are the variations in tuners from very good to bloody woeful. No wonder Joe Average is confused. If you haven't already visited the DTV forum it might be worth your while for advice (both good and bad). http://www.dtvforum.info/ It isn't the definitive answer to all your questions, but at least it's a start and there are some knowledgeable bods there who are willing to share there expertise. Cheers, Alan >On Aug 7, 1:33 pm, "Alan Rutlidge" ><don't_spam_me_rutli...@iinet.net.au> wrote: [quoted text clipped - 31 lines] > >Dave. Try raising or lowering the antenna by 300mm or so. Multipath reflections might be causing some of your problems. > >On Aug 7, 1:33 pm, "Alan Rutlidge" > ><don't_spam_me_rutli...@iinet.net.au> wrote: [quoted text clipped - 34 lines] > Try raising or lowering the antenna by 300mm or so. Multipath reflections > might be causing some of your problems. Tried that, no joy. Thanks Dave. > With digital there is no such thing as good or bad, You ether > have a signal or you don't. Crappo. I consider no drop-outs/pixelation to be "good" and *lots* of drop-outs/pixelation to be "bad". No signal/picture at all would be "really bad" of course. :-) > *** Define "Digital" antenna. One designed specifically for reception of digital transmission frequencies, in your area. One with a suitable feed co-ax and also suitable connections etc. >They don't exist.. Sure they do, as defined. > > Once you get digital you won't go back. > > *** why would you want too ?????? So you can view Ch31/community access TV? :-( MrT. >> With digital there is no such thing as good or bad, You ether >> have a signal or you don't. > > Crappo. I consider no drop-outs/pixelation to be "good" and *lots* of > drop-outs/pixelation to be "bad". > No signal/picture at all would be "really bad" of course. :-) I don't think you have idea, just how digital works. With digital you get a picture or you don't. it's that simple. No snow, no noise, etc. also there is no need for a mast head amp, EVER. regardless of what your installer might tell you. Digital works with a multi-layer of signals, once the signal is transmitted , it's picked up by the forward error correction, [FEC] in the receiver and the best signals are selected and sent to the tuner Most common configuration is 3/4. From the four signals sent it selects three, If it can't find three it simply shuts down . You might get some pixallation in heavy rain, this happens simply because for a few millie-seconds it can't access the signal requirements, If it continues it simply shuts down, until it can work as it should. >> *** Define "Digital" antenna. > > One designed specifically for reception of digital transmission > frequencies, in your area. One with a suitable feed co-ax and also > suitable connections etc. There is no differance between antenna types, they work or they don't. it;'s as simple as that. In some situations plan old "rabbit" ears will work, or a coat hanger, and there's nothing digital about them, >>They don't exist.. > > Sure they do, as defined. examples please >> > Once you get digital you won't go back. >> [quoted text clipped - 3 lines] > > MrT. Not in country area's mate. bassett > >> With digital there is no such thing as good or bad, You ether > >> have a signal or you don't. [quoted text clipped - 4 lines] > > I don't think you have idea, just how digital works. You really don't get it do you "Basset"? I agree with MrT. How often you get drop-out's effectively determines how good or bad a digital TV reception you've got. Lots of drop-outs is certainly "worse" than no drop-outs. Yes it's still digital, but that's not the point. > With digital > you get a picture or you don't. it's that simple. No snow, no noise, [quoted text clipped - 9 lines] > requirements, If it continues it simply shuts down, until it can > work as it should. *yawn* > >> *** Define "Digital" antenna. > [quoted text clipped - 4 lines] > There is no differance between antenna types, they work or they > don't. it;'s as simple as that. You really don't get it do you "Basset"? A "digital" antenna designed just for the digital TV bands of interest is certainly a different "type" of antenna than say an analog Yagi or rabbit ears. > In some situations plan old "rabbit" > ears will work, or a coat hanger, and there's nothing digital about > them, *yawn* Give up dude. Dave. "bassett" > I don't think you have idea, just how digital works. ** This next bit is hysterical ....... > With digital you get a picture or you don't. it's that simple. No > snow, no noise, etc. also there is no need for a mast head amp, > EVER. regardless of what your installer might tell you. ** Wow - not even with 200 metres of co-ax after the antenna .... > Digital works with a multi-layer of signals, once the signal is > transmitted , it's picked up by the forward error correction, [FEC] > in the receiver and the best signals are selected and sent to the > tuner ** Hmmmmm - just like the TV ad says : Its the BITS that John West rejects that make the TUNA work best .... > Most common configuration is 3/4. From the four signals sent it > selects three, If it can't find three it simply shuts down . ** ROTFL !!!.. Everyone knows that 2 out of 3 ain't bad !!! > You might get some pixallation in heavy rain, ** The connection with " pixies " here is getting very strong. " bassett " is chasing them all over the damn place !!!!! ....... Phil > >> With digital there is no such thing as good or bad, You ether > >> have a signal or you don't. [quoted text clipped - 5 lines] > I don't think you have idea, just how digital works. With digital > you get a picture or you don't. Funny then that I have a digital STB and a digital PVR that both give picture drop-outs on occasion. And I am in a good signal area. My friend who also has a STB and PVR suffers *far* worse problems. I suggest it is YOU who has no idea! > it's that simple. Or you are! :-) > >> *** Define "Digital" antenna. > > [quoted text clipped - 6 lines] > ears will work, or a coat hanger, and there's nothing digital about > them, Pity you can't read the definition given, or simply can't understand it. But I am indeed envious if you live in a rural area and *never* get any signal problems, especially with an "old coat hanger"! :-) > >>They don't exist.. > > > > Sure they do, as defined. > > examples please Others have already posted examples. Have you looked at those yet? MrT. > I don't think you have idea, just how digital works. With digital > you get a picture or you don't. it's that simple. No snow, no noise, > etc. This much is correct. > also there is no need for a mast head amp, EVER. regardless > of what your installer might tell you. Total rubbish. In a marginal area a GOOD low noise amplifier at the Antenna will give better reception as with any other form of transmission system. It must have a very low noise figure and enough gain to make up for any feedline loss and splitter losses between the antenna and the receiver. Lots of gain is not better but an amplifier can make an otherwise unreceivable signal watchable. There is a requirement that there be a carrier to noise ratio of at least 19+ dB at the antenna to receive DVB COFDM transmissions with a 23Mb/s data rate. bassett also wrote.... > Digital works with a multi-layer of signals, once the signal is > transmitted , it's picked up by the forward error correction, [FEC] [quoted text clipped - 5 lines] > requirements, If it continues it simply shuts down, until it can > work as it should. This is the most hysterically funny explanation of how digital works that I have ever seen. It just proves how clueless bassett is about things digital. Firstly there are not 4 layers of anything transmitted. The transmitted signal used for terrestrial transmission in Australian standard digital consists of either 2K (some 1700 carriers) or 8K (some 6000 carriers) in quadrature each modulated with 64 QAM (Quadrature Amplitude Modulation) giving a stream data rate of 23.052768 Mbits/S with our normal FEC and guard interval. The use of FEC is a method of transmitting extra bits with the wanted stream MPEG data to make it more rugged. The FEC is not in the receiver it's transmitted as extra data bits in the stream that allow reconstruction of damaged packets in the receiver. What 3/4 FEC means is that for every 3 actual bits of data an extra bit is transmitted as FEC. In other words for every wanted 3 bits of information 4 are transmitted. NOT 4 signals only one with extra information. Small corruptions of the stream data will not cause pixellation as the FEC allows the damage to the data to be corrected and no visible degradation is seen. If the data is corrupted more than the FEC being transmitted is capable of correcting then either pixellation will occur or the decoding will fail. If high values of FEC are transmitted such as 1/2 where every bit in the stream is transmitted twice there is obviously more correction available but at the penalty of loss of wanted data rate. In particular on satellite transmissions FEC values of 1/2, 2/3 or 3/4 are usually used especially 1/2 or 2/3 where small dishes are being used for reception. The more robust forms of FEC are not generally used in terrestrial digital transmissions as there is a need for the highest possible data rate to be able to transmit HD and SD at once in the same stream. >> I don't think you have idea, just how digital works. With >> digital [quoted text clipped - 81 lines] > digital transmissions as there is a need for the highest possible > data rate to be able to transmit HD and SD at once in the same stream. Whatever,, But it strange that all the experts are having trouble and all the dickheads have perfect reception. bassett > Whatever,, > But it strange that all the experts are having trouble and all the > dickheads have perfect reception. May be on to something there :-) I have an old antenna that has been in use for 15 years, with a couple of TVs. (roof mounted, and I am approx 15 Kms from Mt Cootha TV towers) Bought a 101cm Samsung LCD two months ago, and set it to auto tune in the stations, the tuner "failed" to select any analogue stations, but then searched in digital mode and tuned in all the stations with excellent reception. I also have foxtel, so no problems here :-) btw, the Samsung is great. >> Whatever,, >> But it strange that all the experts are having trouble and all the [quoted text clipped - 10 lines] > I also have foxtel, so no problems here :-) > btw, the Samsung is great. So, we could say that your 15 year old antenna, is a digital only antenna, seeing as it failed to tune any analogue signals. Now all the experts will tell you that, the Tuner was digital, so why would it tune analogue. but the facts are the facts, and your watching your Samsung, and as you say there good sh.t. Well done, And by the by, our know-all mate, with the digital antenna link, I suggest you check out the Strathfield catalogue, [back page] It shows the dead spit of your 32 element UHF / VHF antenna. $59.95. No talk about it being digital AT ALL bassett > Whatever,, > But it strange that all the experts are having trouble and all the > dickheads have perfect reception. At least you now realise you are a dickhead. Anyone can get lucky, but there is no evidence that "all" the other dickheads have perfect reception. MrT. >> Whatever,, >> But it strange that all the experts are having trouble and all the [quoted text clipped - 4 lines] > > MrT. There is and lots of it but it is anecdotal > >> Whatever,, > >> But it strange that all the experts are having trouble and all the [quoted text clipped - 4 lines] > > > There is and lots of it but it is anecdotal I fail to see how any unspecified anecdotes can prove ALL dickheads have perfect reception, but I will accept you have just provided one example at least. MrT. >>>> Whatever,, >>>> But it strange that all the experts are having trouble and all [quoted text clipped - 11 lines] > > MrT. trying to make a funny point again I see T , and failing >>>>> Whatever,, >>>>> But it strange that all the experts are having trouble and all [quoted text clipped - 14 lines] >> > trying to make a funny point again I see T , and failing Trying would be the operative word "atec" He trying all right, Bloody trying. I think someone pissed in the puddle he was playing in. bassett >> >> Whatever,, >> >> But it strange that all the experts are having trouble and all [quoted text clipped - 12 lines] > > MrT. Never mind, you see that's the difference between a dichhead and a fuckwit, But you will learn that when you reach the age of six. bassett > Never mind, you see that's the difference between a dichhead and a > fuckwit, But you will learn that when you reach the age of six. Who told you then? MrT. >> Never mind, you see that's the difference between a dichhead and >> a [quoted text clipped - 3 lines] > > MrT. Who told me what, "Petal" > <100246.2...@compuserve.com> wrote in message > [quoted text clipped - 90 lines] > dickheads have perfect reception. > bassett I think it's more of a "Dont confuse me with the facts.. my minds made up" situation Bassett! "bassett" > Whatever,, > But it strange that all the experts are having trouble and all the > dickheads have perfect reception. ** Peeeeeeuuuuuueeeeeeeee !!! " bassett " just did a very smelly fart ........ Outside, doggy - outside right now ..... ....... Phil > "bassett" > [quoted text clipped - 9 lines] > > ....... Phil This thread now degenerates down to Phil's level, Do not pass go, do not collect 200, go back to Aus Hi-Fi, and annoy no-one bassett "bassett" Peeeeeeuuuuuukkkkeeeeeeeee !!! " bassett " just did another very smelly fart !! Outside, doggy - outside right now ..... Or you will get a good kick up the bum. Like you deserve. ......... Phil So, you obviously never worked in the industry! With digital signals, if the signal is on the edge, it will start to give pixellations. This is because parts of the data packets can be missing due to the noise level being too high in relation to the weak signal. As for antennas, they can be very sophisticated with distribution amplifiers and etc. I am not talking about a simple pice of wire, which is not realy a very high performance type antenna! Below is an example of many instances where TV pixelation has occurred due to poor reception. ________________________________________________________ From: http://calypso.tux.org/pipermail/novalug/2007-June/006197.html Now to the problems: TV Pixelation: I had a tech tell me that the TV signal strength was borderline and that would potentially cause some pixelation. There was a ticket open to look into this since June 3rd and I have been told to call weekly as long as the problem persists. The real problem is that this will affect all 24 people who share a fiber termination point with me ..but because I am the first they are not getting enough complaints to come out and fix it yet. Its a minor annoyance and we encounter maybe 15 seconds of it a night and I have yet to see it once on a recorded program. Outage: 3 days after they installed the service ..it stopped working ..not everything mind you just the Phone and internet. So I call tech support ..and I am routed into an IVR system that does the diagnostic for you then opens a ticket ..no option for a human being. I was told I should have a fix by 6 hours later (8pm on a thursday). Well 4 hours later I call back to check ..still stuck in the IVR system I am told the ticket won't be fixed for 24 hours. So the following day from work I connect to Verizons web support chat, where I am told that the box on my house( a module in the NID) is not communicating correctly. Long story short ..no tech on Friday either but I got angry enough to get through to a human being on the phone (via cell of course as the home phone is dead) and got promised a tech first thing Saturday morning. So first thing Sat ..tech shows up, he replaces a module inside the NID ..calls in to activate it ..and POOF problem fixed. ___________________________________________________________ SignatureJANA _____ >> With digital there is no such thing as good or bad, You ether >> have a signal or you don't. > > Crappo. I consider no drop-outs/pixelation to be "good" and *lots* of > drop-outs/pixelation to be "bad". > No signal/picture at all would be "really bad" of course. :-) I don't think you have idea, just how digital works. With digital you get a picture or you don't. it's that simple. No snow, no noise, etc. also there is no need for a mast head amp, EVER. regardless of what your installer might tell you. Digital works with a multi-layer of signals, once the signal is transmitted , it's picked up by the forward error correction, [FEC] in the receiver and the best signals are selected and sent to the tuner Most common configuration is 3/4. From the four signals sent it selects three, If it can't find three it simply shuts down . You might get some pixallation in heavy rain, this happens simply because for a few millie-seconds it can't access the signal requirements, If it continues it simply shuts down, until it can work as it should. >> *** Define "Digital" antenna. > > One designed specifically for reception of digital transmission > frequencies, in your area. One with a suitable feed co-ax and also > suitable connections etc. There is no differance between antenna types, they work or they don't. it;'s as simple as that. In some situations plan old "rabbit" ears will work, or a coat hanger, and there's nothing digital about them, >>They don't exist.. > > Sure they do, as defined. examples please >> > Once you get digital you won't go back. >> [quoted text clipped - 3 lines] > > MrT. Not in country area's mate. bassett > So, you obviously never worked in the industry! > [quoted text clipped - 97 lines] > Not in country area's mate. > bassett What in heavens name does a cable problem with Verizon have to do with AUSTRALIAN digital TV? This is an Australian newsgroup and we use DVB not ATSC which is totally different in transmission methods. > With digital there is no such thing a s good or bad, You ether > have a signal or you don't. *** cough **** *** cough **** ABSOLUTE BULLSHIT. You have a signal that gives a picture but it breaks up and pixellates. I would regard that as BAD! >> With digital there is no such thing a s good or bad, You ether >> have a signal or you don't. [quoted text clipped - 5 lines] > You have a signal that gives a picture but it breaks up and pixellates. I > would regard that as BAD! And if it doesn't break up or pixellate, that's GOOD, have you always been a f.ck-wit, or did Centrelink retrain you. bassett > So I wonder will going digital help? > If the signal is weak and borderline for analogue > TV, will a digital box pull out anything? It's my experience that most digital receivers give a small amount of pixel break-up infrequently with a strong signal, and a large amount of frequent break-up, or no picture at all with a very weak signal. The performance of digital tuners varies just as much as analog tuners, however frequent digital drop-outs can be even more annoying than a poor analog signal IMO. I suggest you simply try a STB that can be returned if unusable in your location. MrT. >I have analogue telly at the moment. I use three >antennae for VHF low, VHF high, and UHF going [quoted text clipped - 10 lines] >If the signal is weak and borderline for analogue >TV, will a digital box pull out anything? I have very variable analogue reception here in a unit in Hamilton, Brisbane. At some time, each channel is hardly watchable, especially ch.7; at other times, they are all bearable. However, the digital reception is pretty close to perfect. There are occasional pixelations, picture break-ups and annoying loud audio artifacts, but they may well be the result of the tuner. To answer the question: get a STB and try it - you've got nothing to lose. SignatureMichael Bednarek http://mbednarek.com/ "POST NO BILLS" >I have analogue telly at the moment. I use three > antennae for VHF low, VHF high, and UHF going [quoted text clipped - 10 lines] > If the signal is weak and borderline for analogue > TV, will a digital box pull out anything? The only sure way to know is to borrow a stb and try - remember you don't need any reception below ch6 (analog) for digital channels and that gets rid of a lot of noise. A friend who lives in the direct shadow of a shopping centre in the inner west of Sydney has absolutely no analog reception but when he installed a Fracarro digital antenna he was able to pick up all Sydney digital stations by pointing the antenna at a building nearly 90 degrees off the correct normal direction - his only panic is if they ever redevelop that 5 story block of units! So it's worth getting an Antenna specialist out to do some in situ measurements... Because you are using a triplexer, you may need a CATV type amplifier for the antenna. It is possible that you will need an amplifier for each band, and use the proper traps for them. This is something that will require the services of a professional installer. He would start by evaluating the antenna with a spectrum analyser to make sure that it is in spec, and then work his way back to determine the exact needs. As far as a digital TV with a digital tuner is concerned, it will only get digital programs as long as they are being transmitted in digital. This means that in your case the stations being received would have to have their program content on their signal carrier in digital, and not in analog. When a consumer digital TV is receiving an analog signal, it will work just like an analog TV is concerned. This means that if the signal is noisy, the set will reproduce the noise just the same way as any other analog TV. In fact, a high end TV will usually be more sensitive to the noise, and the viewer would probably see the noise a lot better! If a digital TV is receiving a digital signal, and the reception is weak, as long as the signal data is above the capture threshold of the TV's receiving and processing system, the picture should look very good. If the signal goes below the capture threshold, the viewer would normaly see pixelations in the picture content. The audio would probably be also dropping out and in with the signal variations. The amount of signal required for a digital TV to have stable reception depends on the capture threshold. Some digital TV models can work down to 10% to 15% signal in relation to a normal level. This means that the set may work up to about 85% noise content in the signal. This subject is very hypothetical. The above is only an example. There are many factors and variables involved. The proper answer is to get a professional antenna installer in, and let him check it out and make the proper suggestions. At the same time he can also check out the TV set. I have seen people complain about an antenna or cable installation, and it turned out the fault was in the tuner or IF section of the TV. SignatureJANA _____ I have analogue telly at the moment. I use three antennae for VHF low, VHF high, and UHF going into a triplexer. Thus I can adjust each one separately. The VHF high (for 7, 9, and 10) is the problem, probably because the channel 10 transmitter is in a different direction to 7 and 9. I have moved the antenna all over the place, but can't get a good picture on all three. After last attempt I have channel 7 the noisiest, and if it rains, the picture drops back to black and white. I can't raise the anntenna any higher. So I wonder will going digital help? If the signal is weak and borderline for analogue TV, will a digital box pull out anything? |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.