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Any recent 5th generation receiver chip news? - Page 9

post #241 of 433
Quote:
Originally posted by jdallaire
Hi folks

I just found the following at digital-connection the New Fusion 5 features LG's 5th Gen Tuner PC card . This baby is set to ship ETA 5-23-2005. I hope the new set top boxes with the 5th gen chip are coming next. Anyway I hope that maybe someone could give us more reviews of this chipset. I know it probably needs to be in the HTPC area. But I thought folks here might be interested in the news.

At this point I think most of us (I know I am at least) are wanting to know if LG's 5th actually performs as well as the prototype LG tuner that was tested in a NYC apartment almost two years ago. This thread has received positive word that the 5th gen demod is working well integrated in LGs TVs.
There was another test in NYC recently with a STB not made by LG but uses the 5th gen demod and the results were not as good as LGs prototype STB. I personally do not care whether this demod is in a TV, STB or PCI card. I am very interested to see if this demod is truly the answer to multipath problems. If it is, then I would be very interested in getting an LG 5th generation STB. I would prefer it be made by LG but that may never happen.
The digital-connection ETA of 5-23-05 is sort of a downer to me as the ETA last week was set for 5-16-05.
post #242 of 433
Hi GSfromCT
We need more reviews of the 5th gen performance so I hope members here help us with more reviews. If the 5th gen set box were available today I would be the guinea pig for testing. I hope we see some boxes early this summer. OTA air reception maybe the only way some folks will be able to get true full bandwidth HDTV. Sat. has HD lite. My local cable wants to use its bandwidth for its movie on demand systems and all ready don't broadcast the the WB and UPN because of bandwidth issue's.
post #243 of 433
Well, I think the whole 5th gen chipset issue is way overblown. The current generation of receivers works very very well for the vast majority of viewers.
post #244 of 433
I wonder if it would make sense to switch to a less directional antenna and let the 5th gen chip electronically handle the multi-path or continue using my current antenna that physically reduces multi-path? Is it possible that each path could be combined electronically to produce a better signal than trying zero in on just one of the paths?
post #245 of 433
Hi Rich Peterson

I think I need to clear something up. The problem I am see is for indoor reception. Apartment Urban condo developments. I have better luck with simple rabbit ears with analog UHF reception then digital receptions. Indoor Digital reception is allot harder then analog. I am being unrealistic in expecting all my local station within an eight mile distance to come in? I have a small hill between me and the tower field the hill is in the 100' foot range. By the way I also had issue's pick up 3 local station with an outdoor antenna using a Motorola's box. Are my expectations just to high?
Tuner today are just not for prime time for indoor reception nowhere near plug and play.
post #246 of 433
I too am waiting for the 5th generation sets. It seems kind of silly that people 60 miles away from the towers have no problem with reception but if you live within 15 miles of the transmitters multipath makes HDTV reception totally unwatchable. I don't think the issue if 5th gen tuners is overblown.
post #247 of 433
Quote:
Originally posted by Rich Peterson
Well, I think the whole 5th gen chipset issue is way overblown. The current generation of receivers works very very well for the vast majority of viewers.

Hardly overblown!


Those of us living in large metropolitan areas, and there are a lot us; and we spend a lot of money for digital television. We desperately need better technology to allow us to properly receive over-the-air signals.

Between where I live in Manhattan and the transmitting antennas atop the Empire State Building, there are numerous buildings taller than Minneapolis' tallest - 225 South Six.

I only wish I and others had your reception problems!

So before we are castigated, please try to be understanding and compassionate.

Gary Press
post #248 of 433
Quote:
Well, I think the whole 5th gen chipset issue is way overblown. The current generation of receivers works very very well for the vast majority of viewers.

I can't agree. The lack of adequate indoor or multi-direction reception will probably be used in Congress to stall the analog turn-off. It has to be dealt with. I just do not believe the transition can complete using only cheap early generation tuners with inadequate front end circuits.

- Tom
post #249 of 433
Quote:
Originally posted by trbarry
I can't agree. The lack of adequate indoor or multi-direction reception will probably be used in Congress to stall the analog turn-off. It has to be dealt with. I just do not believe the transition can complete using only cheap early generation tuners with inadequate front end circuits.

- Tom

Be careful Tom. You are starting to recite Sinclair verbiage!
post #250 of 433
Quote:
Be careful Tom. You are starting to recite Sinclair verbiage!

Hi Foxeng.

Does that mean you disagree with what I said or just a joke about how it is sometimes not very popular here to say anything questioning some of the ATSC transition decisions.

- Tom
post #251 of 433
Here's my take on this issue. There are not enough HD users who are affected by the applications where you would benefit from 5th generation ATSC tuners. Where 5th generation tuners would be helpful, which is typically downtown metropolitan cites and communities where your HD broadcasts come from more than one tower, many users have figured out a work-around. Like multiple antennas with antenna-joiners, or using master antennas in apartment buildings or just subscribing to broadcast only cable service, with very low monthly costs.

Keeping in mind that many users already subscribe to cable or satellite service and 80% of the users who want OTA ATSC are served very well by their existing built-in satellite ATSC tuner or integrated HDTV or the existing available ATSC STBs that are already available in the marketplace. You just can't get a major company to engineer and manufacture a STB for the low volume of sales that this limited market will buy.

So as the technology matures and new advances become available we see them being built-in to the latest HDTV's instead of as stand-alone devices.

-Robert

Advanced Digital Technology Dealer
post #252 of 433
Quote:
Originally posted by trbarry
The lack of adequate indoor or multi-direction reception will probably be used in Congress to stall the analog turn-off.

Hope this isn't too far OT, but -- speaking of multi-directional reception -- I had ran across a mention in Doug Lung's RF report that there is now one antenna available which utilizes CEA-909(smart antenna) antenna interface which allows the receiver to automatically control adjustment of even a non-rotorized antenna to provide good reception for any given station in any given direction ....

Having not seen any discussion here of such a beast, having read about CEA-909 spec a few years ago and ; #1).being curious whether or not anyone would actually attempt to use it, #2) --- and #3). also recalling your particular dislike for rotors/jointennas and the like :

I did a little looking around and I think I found the antenna Doug Lung was referring to at below link -- It's the DX Antenna DTA-5000 "Smartenna" (DX antenna is subsidary of Funai, BTW) :

http://www.dxantenna.co.jp/trading/p...a/dta5000.html

Googling for "DTA-5000" will also turn up many results of U.S. Vendors(most of whom I've never heard of) which have this antenna in Stock under various brand names(sylvania/samsung/etc), with going price of ~$95~110 ... Unfortunetly, the spec sheets from all these vendors may be a bit confusing, as they all seem to include the following spec:

"TOTAL DIGITAL PACKAGE(TUNER AND ANTENNA), HDTV COMPATIBLE"

I'm fairly sure when they say "tuner", they are actually talking about the antenna control box as specified on the manufactuers(dx antenna) website.

Sylvania also mentions the DTA-5000 in it's info for Funai/Sylvania's 6900DTE ATSC receiver at below link , which according to the PDF file(accessable from "product specs" link at bottom of page), supports CEA-909 interface :

http://www.sylvaniaconsumerelectroni...s/stb/stb.html

Funai also has a press release from 11/04 with more details about the STB+Smartenna ....

http://www.funaiworld.com/company/pr...04/041111.html

Looking at the pic of the DTA-5000, I must say I am a bit dubious ... However, on the other hand - my understanding is that CEA-909 is not snake oil, so I have to wonder how well this thing would work, and if anyone has tried it with a receiver that supports CEA-909 "Smart Antenna" interface ....
post #253 of 433
Quote:
Originally posted by trbarry
Hi Foxeng.

Does that mean you disagree with what I said or just a joke about how it is sometimes not very popular here to say anything questioning some of the ATSC transition decisions.

- Tom

It was a joke, but Sinclair has used the fact that until the FCC creates receiver specs, the transition will not have a happy end with OTA. (they used that in conjunction of why they wanted COFDM, reduced effects from multipath) I agree that if the OTA receivers are not as good as they can be, there will be many unhappy OTA viewers if the receiver manufacturers don't get this fixed. Putting all of their time into cable boxes, like they are now, isn't really helping the OTA situation. I agree with you on that one 100%.

The 5th gen receivers should go a long way (I have already ordered the new 5th gen Fusion HDTV 5 PCI Card and just waiting on it to be released next week). From what people who have seen the 5th gen test receivers in action say, they leave the current crop of receivers in the dust. Not because they are that much better, but multipath is the big killer of signal and not lack of signal. If you read very carefully between the lines, most peoples problem isn't lack of signal, but too many signals being received out of phase and killing the signal to noise ratio (perfectly good signal level then the signal goes away for a second and then comes back, the meters are not really signal level meters but really a combination of signal strength when the signal to noise ratio is within tolerances, signal to noise goes out to lunch, usuable signal drops to zero, signal to noise comes back, usuable signal comes back up) that the receiver needs to have to successfully decode. 5th gen should correct a large part of that.
post #254 of 433
Quote:
Originally posted by DTV TiVo Dealer
Here's my take on this issue. There are not enough HD users who are affected by the applications where you would benefit from 5th generation ATSC tuners. Where 5th generation tuners would be helpful, which is typically downtown metropolitan cites and communities where your HD broadcasts come from more than one tower, many users have figured out a work-around. Like multiple antennas with antenna-joiners, or using master antennas in apartment buildings or just subscribing to broadcast only cable service, with very low monthly costs.

Keeping in mind that many users already subscribe to cable or satellite service and 80% of the users who want OTA ATSC are served very well by their existing built-in satellite ATSC tuner or integrated HDTV or the existing available ATSC STBs that are already available in the marketplace. You just can't get a major company to engineer and manufacture a STB for the low volume of sales that this limited market will buy.

So as the technology matures and new advances become available we see them being built-in to the latest HDTV's instead of as stand-alone devices.

-Robert

Advanced Digital Technology Dealer

I respectfully disagree.

I don't live in a metro area like NYC or Chicago, but even out here in the sticks of North Carolina, I do see the effect of multipath and there are many times when a 5th generation receiver would be helpful. What you cite is the extreme, but for those of us not in the concrete canyons, momentary drop outs caused by multipath such as wind blowing trees, planes flying overhead, 18 wheelers driving by can be more nerve racking than not having the signal at all. It is there for a long time, then gone for a second or two and then back for a while and then gone again for a second or two and then back again......

In my area over 60% of the HD audience gets their network HD OTA, because only 2 of the 8 cablecos offer the local digital signals. The Sinclair ABC digital isn't on any of the cable systems here so for those homes who want Desperate Housewives and Lost in HD, OTA is their only choice and the momentary multipath drop outs drive people crazy because they always seem to happen at the good part. I have personally experienced this myself (the wife just hates when it happens) and I have a CM 4228 on a rotator on my roof (being in the business I do know where all of the towers are, the antenna heights/patterns and power levels) with nothing but trees between me and the transmitter sites. 5th gen receivers will solve that.

Multipath using receivers benefit everyone everywhere and it is a big deal. Just read the different threads here on AVS if you need further proof.

I completely understand you position as an equipment dealer. You have 4th generation stock and you don't want to be stuck with stock you can't sell. I am afraid I don't have an answer for you on that. I know many people who are waiting to buy until the 5th gen receivers are out and they appear to be savvy enough to ask the right questions to be sure they aren't stuck with a 4th gen receiver. I do truly feel for you on that on.
post #255 of 433
Quote:
Hope this isn't too far OT, but -- speaking of multi-directional reception -- I had ran across a mention in Doug Lung's RF report that there is now one antenna available which utilizes CEA-909(smart antenna) antenna interface which allows the receiver to automatically control adjustment of even a non-rotorized antenna to provide good reception for any given station in any given direction ....

Having not seen any discussion here of such a beast, having read about CEA-909 spec a few years ago and ; #1).being curious whether or not anyone would actually attempt to use it, #2) --- and #3). also recalling your particular dislike for rotors/jointennas and the like :

Nitewatchman -

You are correct about my total hatred of rotors, and all directional antennas. But the proposals of mine you may remember are a slightly different solution that AFAIK does not even exist. And since I am not an EE or qualified to design antennas it may not even be possible.

I don't even want the smarts in the antenna. That would just make it a smart rotor, maybe with no moving parts. It would be a marginal improvement but not really get the job done.

The problem here is that it would still point in only one direction at a time. These days it is not reasonable to assume a household will need to simultaneously tune only one channel. For instance PVR's increasingly have multiple tuners, and people also have computers and VCR's recording different things while multiple people may be watching multiple sets in different rooms.

So what I'm looking for is an antenna that sends multiple signals from multiple directions down something like cat6 cable. Then multiple smart tuners in each receiver would figure out which combinations of signals gave the best total signal for a desired channel. This sort of system could be shared in a more realistic way if it was even practical to make.

I don't think any of the items you posted have those properties. Maybe none ever will.

- Tom
post #256 of 433
Noticed an article about these a while back, too, and suggested here that it might be effective to link their all-electronic tuning (phased array, I believe) with the multipath circuits of 5th-gen receivers. The engineered interaction might minimize multipath (phased-array tuning), while making the best use of multipath that can't be rejected. -- John
post #257 of 433
Quote:
Originally posted by trbarry
I don't think any of the items you posted have those properties. Maybe none ever will. But the proposals of mine you may remember are a slightly different solution that AFAIK does not even exist.

I think you are reading too much into my post. Yes, I do recall some of your thoughts/proposals. I also don't know if what you specifically sugguest could be done, but I think if there were a perceived large market for various OTA reception solutions, we would probably see many more innovative products than seems to be the case, currently.

I did not mean to suggest a solution utilizing CEA-909 interface+a antenna such as DTA-5000 would meet your approval as a overall solution for those who want to hook up to multiple sets and have good multi-directional reception on all sets, from all stations in multiple directions at the same time.

My only intent was to provide info which I thought some might be interested in, as I had not seen any info posted on it ... Perhaps I should not have brought up your dislike for rotors/etc, although I did so as I thought you might appreciate this particular, automatic multi-directional reception solution.

Quote:
Originally posted by trbarry

It would be a marginal improvement but not really get the job done.

I have my doubts whether or not this particular solution would be an improvement in many cases, however -- as compared to a directional antenna setup with manual rotor control -- If I were to make a wild assumption that the thing perhaps actually does work in many cases in situations where multipath+stations in multiple directions is a problem : I suppose the level of "improvement" one might perceive or experience depends upon your prespective.

For example, If you think having to manually adjust the rotor controller in order to receive stations in multiple directions is no big deal as compared to having the receiver/antenna do it for you automatically, then I suppose you could think of it as "marginal". On the other hand, if you despise rotors, and are tired of manually having to adjust the rotor controller every time you tune to a different station, you might find a system that automatically adjusts the antenna for best reception from any given station quite an improvement, even if you do have to have a seperate antenna for each Set/recording device/etc, if you want to be able to watch different stations from different directions on different sets at all times ....


Quote:
Originally posted by trbarry

I don't even want the smarts in the antenna.

I'm not sure if much(if any) of the smarts are in the antenna in this case. I was never able to dig up the details on CEA-909 interface, however I believe it works much as John mentions.

As for the antenna itself with the DTA-5000, Hard to say, as I have no idea what is inside the cover but it seems to me that it looks like we are looking at a relatively simple antenna design, which in any case would not seem to look like a antenna that would provide hi-performance when it comes to directivity, signal gain, or rejection of multipath.

Again, hard to say, but it looks like there are a couple of dipoles, perhaps each(or both) which can be selected for use, and perhaps with the capablility to move the antenna elements(dipoles) around a bit in order to utilize the best possible directivity(and/or rejection of multipath) - depending upon what the receiver/control box "tells it to do" in any of 16 different directions ....

Hopefully, we'll soon hear some reports from folks who have actually tried it ....
post #258 of 433
I bought an LG LST-4200A from Value Electronics. This fourth gen tuner is better than any tuner I have had experience with (Samsung 165, ATI HDTV Wonder, JVC 61" DILA with built in tuner). It's sensitivity, features and speed are above all others. I am very happy with it. I'd be happier if the local stations paid serious attention to their PSIP data, and if WETA would get a clue and watch some of their stuff on a large HDTV (macroblocking would drive them wild).

But I hear that the fifth gen tuner is four times as sensitive, amongst other features. My reception in Northern VA of Baltimore stations is spotty at best. If a fifth gen would give me the Baltimore stations, I'd buy it. PBS out of Baltimore/Annapolis is way better in content and picture quality over WETA.

Or would a fifth gen NOT help bring in more distant stations?
post #259 of 433
I have so much respect for you Folks great discussion.

Rich Peterson
Quote:
Well, I think the whole 5th gen chipset issue is way overblown. The current generation of receivers works very well for the vast majority of viewers.

DTV tivo Dealer Robert says
Quote:
Keeping in mind that many users already subscribe to cable or satellite service and 80% of the users who want OTA ATSC are served very well by their existing built-in satellite ATSC tuner or integrated HDTV or the existing available ATSC STBs that are already available in the marketplace. You just can't get a major company to engineer and manufacture a STB for the low volume of sales that this limited market will buy.

This is why Rich probably feels this issue is over blown. It just doesn't effect enough of us OTA users. This is so true.
I am just so disappointed in content providers Cable will not send all locals in High def. They cherry pick which ones they will send at this time No local UPN or WB because of bandwidth restraints. Cable wants Fox but Emmis owns local station and want USDTV and boycotts the signal to cable. Direct TV is into HD lite. I think it's just a matter of time before cable get on a HD lite kick to conserve bandwidth. OTA maybe the last place to get full bandwidth HDTV. I am tired of being jerked around. When I bought my HD plasma TV I never dreamed I would have to battle for HDTV full content. I was wrong. I still want a 5th gen set top box I can dream can't I?

Fxend said
Quote:
It was a joke, but Sinclair has used the fact that until the FCC creates receiver specs, the transition will not have a happy end with OTA. (they used that in conjunction of why they wanted COFDM, reduced effects from multipath) I agree that if the OTA receivers are not as good as they can be, there will be many unhappy OTA viewers if the receiver manufacturers don't get this fixed. Putting all of their time into cable boxes, like they are now, isn't really helping the OTA situation. I agree with you on that one 100%.


History tells us Sinclair had an agenda they wanted COFDM. They knew this multi-pathing reception issue were true. Sinclair also had self serving interset in delaying the DTV roll out.

Those that choose to angnor history are certain to relive it. Here we are going around and around. Did we learn anything?
Later.
post #260 of 433
In our demo room/HD lab we have ATSC and DIRECTV feeds and we switch between OTA and satellite frequently to determine if we can see any pq difference.

I don't know if I should start this sentence with the word unfortunately of fortunately, but either way you look at it the actual image quality is so very negligible that on most stations no one can see any difference on on the occasional broadcast where you can see a difference it is so little that I doubt you would notice or care if you did.

Posters who talk about DIRECTV HD lite are putting the wrong ideas in the readers minds. DIRECTV's compressed video is excellent HD image quality to all who have the pleasure to have it.

-Robert

VE Advanced Digital Technology Dealer
post #261 of 433
Quote:
Originally posted by jdallaire
History tells us Sinclair had an agenda they wanted COFDM. They knew this multi-pathing reception issue were true. Sinclair also had self serving interset in delaying the DTV roll out.

Those that choose to angnor history are certain to relive it. Here we are going around and around. Did we learn anything?
Later.

Sure they had an agenda, I won't argue that point with you. With 60 some stations to convert that was a huge chunk of change and yes, just like every other OTA broadcaster, didn't want to spend it.

But if you have to spend that kind of money, in Sinclair's case well over $250 million just for transmission, not even counting studios and microwave links, they wanted the best opportunity to recoup that money, no matter what it was. At the time all of this came out, the biggest negative with 8VSB was the fact that it was so prone to multipath, that many in the industry besides Sinclair doubted receivers would stay locked with rabbit ears in fixed locations and forget about mobile operations. Wasn't going to happen. The ATSC proponents kept saying that it was a problem that could be fixed, but it would take time. Most people didn't think we had that much time. Sinclair took the tact that they did to either get COFDM the new standard or get it where you could use either 8VSB or COFDM. I can tell you that MANY in the industry secretly supported them, but wouldn't come out and say it because they feared retributions like Sinclair got.

Up until I personally saw an OTA signal of 8VSB in a home setting a couple years back, I too was skeptical if the industry could pull this off. But if what I have seen in the specs and reports of the 5th gen receivers, it should put digital TV pretty close in footing with analog TV and that is all the broadcasters are really worried about. Now what Sinclair has in mind or wants to do, you will have to ask Bob Smith of Sinclair. He is the only one there who really knows.
post #262 of 433
Hi foxgen
Quote:
the biggest negative with 8VSB was the fact that it was so prone to multipath, that many in the industry besides Sinclair doubted receivers would stay locked with rabbit ears in fixed locations

Yep this says it all.

Just give us the 5th gen in a set top box please.
post #263 of 433
Quote:
Up until I personally saw an OTA signal of 8VSB in a home setting a couple years back, I too was skeptical if the industry could pull this off. But if what I have seen in the specs and reports of the 5th gen receivers, it should put digital TV pretty close in footing with analog TV and that is all the broadcasters are really worried about. Now what Sinclair has in mind or wants to do, you will have to ask Bob Smith of Sinclair. He is the only one there who really knows.

AFAIK about the time of the test of that strange miracle box in Mark Shubin's NY apt about a year ago it seemed that Sinclair became convinced and has been an ATSC chearleader. I was myself for awhile until it became clear there were good 5'th gen boxes and bad 5th gen boxes, with no obvious way to buy the good ones or know really what the difference was.

It did seem that if all ATSC STB's were as good as that one test box then we could complete the transition and stop worrying about it, at least as far as multi-path is concerned. It was fairly undirectional. I have not recently heard anything from Sinclair to contradict this.

But I'd guess that like most of us here Sinclair would like to see someone start marketing the "good" 5th gen boxes and put at least one issue to bed. Zenith still refuses to do it. I had hoped things would change once the broadcast flag issue was settled but maybe there is a bit more delay yet.

- Tom
post #264 of 433
Thread Starter 
Well, according to the infamous Bob Miller, at least one Asian company is still trying to perfect a 5th chip LG OTA box. I hope they succeed. They are getting help from LG.

In my city, no stations are broadcasting at full power. They may start to do so in late June to meet some FCC July deadline. Only then can I tell if I really need a new receiver. I get most stations most of the time now, but it varies and I have to fool around with the indoor antenna position. For several months I got them all, all of the time, but seasonal climate change or something has degraded that reception capability. Also, my local Fox station is under funded and keeps messing with their signal. It's funny, the Fox technician has a European name but a Japanese accent. He sounds like the Japanese actor from the original Star Trek series. I call him up he tells me about how there are so many things that can go wrong with a digital signal. The Fox station has little monitoring equipment, so I don't think he minds my feedback on reception.

What we need is complete analog cut-off. Then there will be pressure on broadcasters and receiver makers to put their best foot forward. Now there is hardly a motive to give a damn.

IB
post #265 of 433
Quote:


Originally posted by inky blacks
.....at least one Asian company is still trying to perfect a 5th chip LG OTA box. I hope they succeed. They are getting help from LG.

I'm also working on this issue.
post #266 of 433
Thread Starter 
Quote:


Originally posted by Ken H
I'm also working on this issue.

Great. Would you care to expand and clarify that statement?

IB
post #267 of 433
Thread Starter 
Look at this. IB
----------------------------------------------------------------------
http://www.engadget.com/entry/1234000500042416/

The Clicker: Single Frequency Networks and OTA HDTV
Posted May 5, 2005, 4:20 PM ET by Peter Rojas
Related entries: Displays, HDTV, Home Entertainment

Every Thursday Stephen Speicher contributes The Clicker, a weekly column on television and technology:


One look at the eye-popping picture and you were hooked. The window-like effect dazzled you. You all but drooled over the rock-solid picture. There's no snow. There's no ghosting. The resolution is to die for. You saw the light and its name was High-Definition. There's only one problem: you can't seem to pull in a reliable OTA (over-the-air) signal.

Oh sure, cable is an alternative for many. However, over the years, you've been spoiled; you're hooked on your PVR. And, as a connoisseur of PVRs, you understand that the cable companies offer anemic light-weight versions. You demand more. You're not happy unless you've got your TiVo or your MCE (Microsoft Media Center Edition). You've even been known to utter the phrase, They'll have to rip my TiVo out of my cold dead hands. Worse yet, you meant it - LITERALLY.

Fear not - all hope is not lost. Despite previous attempts to scale your house with antenna in hand only to be denied a clean signal, there are two reasons to still have hope: a) Single-Frequency Networks and b) 5th generation receivers.

Since the beginning of broadcasting nearly all stations have followed the same steps when it comes to transmitting their signals: a) do your best to locate the tower in the middle b) build the tower high and c) add power. The problem is that, in some regions, this method just doesn't cut it. Natural terrain presents issues as do man-made buildings. Signals bounce around or, worse yet, fly right over your head. If State College, Pennsylvania's WPSX is a harbinger of things to come, the answer to your woes just might be Single-Frequency networks (SFNs).

More commonly discussed within the context of Europe's COFDM, SFNs are beginning to show signs that they might just work with America's 8-VSB modulation scheme also.

So what are SFNs?

Simply stated, single-frequency networks are when a broadcaster uses multiple transmitters to send the same signal over the same frequency. The idea is that in certain geographically-difficult areas broadcasters will have much better success if they can fill coverage voids by utilizing smaller, usually-less-powerful satellite towers in addition to their main tower.

It sounds like a simple idea, but, as always, the devil is in the details. Unlike the repeater towers that are sometimes used in western states (AKA translators), SFNs aren't simply receiving the signal, error-correcting, and retransmitting on a different frequency. That is an extremely inefficient use of the spectrum.

So what are they doing?

There are two main methods of creating a single-frequency network. The first is through the use of on channel boosters. On channel boosters quickly receive the OTA signal from the main tower and retransmit the signal on the same frequency. The problem is that there is no error correction. So, any errors in reception are simply retransmitted along with the slight echo caused by the booster itself. On channel boosters are also limited in their placement as they need reliable reception from the main tower.

So, when WPSX took the plunge into SFNs, it opted for option two, distributed transmission. Working with the New Jersey-based Merrill Weiss Group, WPSX has created one of nation's most technologically-advanced broadcasting systems.

With distributed transmission, the signal is delivered to each of its transmitters via fixed channels (land-based delivery). Then through the use of GPS-based reference clocks at each tower (for both time and frequency), the signals are synced so each can emit a perfect copy of both signal and symbol data. The result is a group of towers working in harmony.

So why isn't this done more often (at all)?

No matter how synchronized the output from the towers may be, there will always be some amount of multi-path to deal with, and until recently receiver hardware wasn't equipped to handle anything but very minor levels of multi-path. Multi-path? Yes, multi-path is the result of your receiver seeing the same signal more than once. This can be caused by a variety of things. For instance, in a crowded downtown area the signal can bounce off buildings many times before it hits your antenna. The problem occurs when some copies of the data arrive more quickly than others. This, in effect, can jam your receiver.

The same effect occurs within SFNs. Because waves from different towers have the potential to reach your antenna at different times, a receiver's ability to handle multi-path is paramount to its success.

With that said, LG has continued to make great strides in their ability to handle multi-path issues. Through the use of techniques such as adaptive equalizing they have even begun to turn a negative into a positive. First generation tuners had a multi-path window of -3 to +10 us. Fifth generation tuners have increased that window to -50 to +50. As always bigger numbers are way better.

So, if you're like me, unable to receive a signal despite near-heroic efforts. Have hope; there's technology out there that might just help one day.

But for now - we wait.
post #268 of 433
I hate articles that generalize how it seems almost impossible to pull in reliable OTA HD. That's just pure nonsense and does nothing to promote the great potential that's out there. Surely some people have problems, but many don't.
post #269 of 433
Quote:


Originally posted by Ken Ross
I hate articles that generalize how it seems almost impossible to pull in reliable OTA HD. That's just pure nonsense and does nothing to promote the great potential that's out there. Surely some people have problems, but many don't.

Well I've noticed that many people in the most multipath challenged areas (NYC and LA/SoCal) tend to assume that there is nobody living or using digital TV elsewhere in world.

PS: I've always been a bit curious about how analog OTA TV looks in these locations ...
post #270 of 433
Please remember that many people in suburban and rural areas also suffer from multipath. It is a serious problem for many people and needs to be addressed if OTA is to be taken seriously.
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