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Quote:
Originally Posted by MeowMeow /forum/post/14792863


But don't be surprised if a number of LPs never make the transition. There are stations running on such low budgets that if the feds force them digital, it's going to be more cost effective to go off the air for good.

Yeah, but the Feds seem to be feeling pretty generous with our money in terms of handing it out to keep businesses afloat these days, so maybe these LPs would get a little Congressional pork to pay for the transition...
 

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Quote:
Originally Posted by ziggy29 /forum/post/14793614


Yeah, but the Feds seem to be feeling pretty generous with our money in terms of handing it out to keep businesses afloat these days, so maybe these LPs would get a little Congressional pork to pay for the transition...

At the end of the day, though, it's up to the FCC to explain to Congress why the money is needed.


Hopefully there is enough of the spectrum auction money left to easily justify paying some aid to LPs. But, I don't imagine that issue is going to be discussed until after Feb 2009. Obviously, the next few months are going to be entirely about making sure the full power stations make the transition with the least damage possible.
 

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Quote:
Originally Posted by dattier /forum/post/14789860


* May we gather that "the end of the transition period" means the end of the transition period for full-power stations, i.e., February 17, 2009?

That's how I read it, and regarding Ch. 60~69 reallocation order and its modification of the Freq table -- Again, unless something has changed .. And, note while trying to "look this stuff up", I did see a FCC document from 2007 which seemed to indicate nothing had changed regarding the ch 60~69 reallocation order, so it doesn't "seem" to have changed ...


The way I understand it, it was really enacted by congress (involving Communications act), and FCC can't change that "on their own" anyway ...


That being said, I don't know and am just guessing, but I suppose it may be somewhat possible FCC *could* (I wouldn't think they would though, but who knows) make some exceptions and allow some LP's on 60~69 to stay up a bit beyond Feb 18, *IF* they don't cause interference to new services (including the new Public safety services which will be using portions of that spectrum). Especially perhaps if nothing "new" will actually be using the spectrum involved in any given area for a while ....


I do know, in my area, except for W66AQ (which again has a CP to move to 22), Most of the LP's which were out of core have all already moved in core over the past several years -- Or, in the case of 2 KET LP translators on 56, have recenty fired up in-core DTV operations on digital companion channels .. ...


There is a Translator on 63 (W63AH, Maplewood Ohio, translator for WPTD) which last time I looked them up on FCC site hasn't seemed to have done anything(such as file a displacement app or look for DTV companion channel), whearas another of their translators (W17AA, Celina, OH) Has filed for DTV Flash cut .... I'm not sure whether or not they plan to continue to operate a Maplewood translator post-transition or not .... Takes a little enhanced "tropo" for me to see them, but I did notice they were still there on 63 last time that happened and I looked ...
 

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Quote:
Originally Posted by mattdp /forum/post/14793403


I know for a fact that TBN isn't exactly scraping by, and they've got a vested interest in digital TV with their five channel digital multicast.

TBN seems to have construction permits for LDs all over the country so they'll probably convert to digital quickly. It would also appear that all the out-of-core LPs in the Pittsburgh area except one have at least applications for in-core channels. It looks like the owner of that one hopes to combine it with its sister station from the same location going to a single non-directional digital station.
 

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What's going on with TV FOOL???? They have changed things quite a bit. My results are completely rediculous now. They must still be tweaking it.
 

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I was about to say the same thing. It shows my two strongest stations as barely receivable, and the weakest station as the strongest. It doesn't even list WDRL anymore.


- Trip
 

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Quote:
Originally Posted by Digital Rules /forum/post/14804280


What's going on with TV FOOL???? They have changed things quite a bit. My results are completely rediculous now. They must still be tweaking it.

There was a database update on September 30. Some of the results (including one of mine from KTBC in the Austin market) seem to be incorrect now.
 

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Discussion Starter #268
After much deliberation, the format of the Signal Analysis reports has undergone a significant overhaul. This may come as a shock to some long-term users of the site, but we hope that these changes will actually make things easier for most people in the long run.

What's New

Signals are now ranked by Noise Margin (NM) as opposed to dBm.

It's still a bit technical for most people, but this should make a little more sense than dBm. Simply put, Noise Margin is your signal level (in dB) relative to the minimum level needed to watch a channel. At negative NM values, you cannot decode / view a channel. At 0 dB NM, you can just barely get the channel. At positive NM values, you can receive the channel and have a bit of padding to help deal with multipath, interference, weather changes, and other random signal fluctuations.


NM automatically compensates for the differences in channel type. There was some FUD circling around about poor digital coverage because of their much lower transmitter power. However, the truth of the matter is that digital (ATSC) signals can do a lot more with less power than analog (NTSC) signals. Comparing channels on the basis of NM puts analog and digital channels on nearly equal footing so that now the "all channels" plots can merge the two lists in a more meaningful way. People should be less focused on the raw signal power because that's not what determines a channel's reception quality.
Power levels (dBm) are still listed, but they have been adjusted to align with expected "real-world" power levels

There was often confusion about how the F(99,99) models resulted in theoretical signal levels (like -110 dBm) that should be impossible to receive if you're comparing that to a thermal noise floor of -106.1 dBm and a minimum detection threshold of 15.2 dB for ATSC (meaning the cutoff should be -90.9 dBm). This "conservative bias" has be eliminated so that values in the "Pwr(dBm)" column should agree more closely with the "normal" power levels people are used to dealing with and what they might actually measure on a spectrum analyzer.Anyone who got used to the dBm scale from previous TV Fool reports will have to re-adjust their thresholds because the scale has changed. On the plus side, everyone can now think in terms of Noise Margins instead of dBm levels. This way, you don't need to keep separate thresholds in mind for analog vs. digital channels.


If people live very close to some transmitters, the power values in this column will be highlighted in red to warn them of possible overload conditions in their amps or receivers. It's just an estimate, of course, since actual overload conditions will depend on antenna gain, antenna pointing, and overload tolerance of the electronics.
The "Xmit(kW)", "-100 dBm", and "LOS" height columns have been removed

Some people were confused by the meaning of these columns. Some even thought they needed an antenna of the specified height to get reception. A few people found the columns useful for gauging terrain blockage severity. However, the main reason for removing these columns was to create more real estate to make room for a larger radar plot and make it possible to list more channels per report. Although it's always difficult to discard useful information, I think the tradeoff in this case was justified. An alternate title for this news release might have been "So much information, Not enough space!"
The size of the radar plot has been increased

The new table arrangement has made it possible to increase the radar plot size. This will hopefully make it a little easier to read the transmitter directions and channel numbers. It will probably also show up better when printed.


The yellow highlight on VHF stations has also been made stronger so that more people will take notice if any of their locals are on VHF. We just want to make sure nobody is caught off-guard by having the wrong kind of antenna!
Analog and digital transmitters are no longer red and green

The color coding has been changed to more of a purple and blue color scheme because the red and green text was sometimes being misinterpreted as being related to the background color and reception liklihood. We also think the new color scheme improves readability, but that's just a subjective opinion.
The overall image size has been changed to 800x768

It is very important to us that the TV Fool reports are an acceptable size to be posted on the most common discussion forums relating to OTA TV. We want to do our best to bridge the gap between the helpful people responding to questions and the people asking the questions. The lowest common denominator among the biggest forums seems to be 1024x768 and 800x800, therefore, the largest size that should be allowed at all sites should be 800x768. Previous TV Fool reports were 800x600, so this is an increase of 28%


This allows us to increase the maximum number of channels listed on each report to about 51. The old limit was aboutn 35 channels, so this should be a big help to DXers or anyone else trying to explore the weaker channels toward the bottom of their lists.


We hope you'll learn to like the new changes.
 

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TV FOOL was 98% accurate for me before. Now stations that I never have, or never will get, rank ahead of stations that are 24/7; or frequently recievable at night. Has any real world testing been done? IMO, as it is now; it's pretty much useless.


"IF IT AIN'T BROKE, DON'T FIX IT"
 

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Andy,


My TV Fool plots are no longer accurate. It shows San Diego stations in the green, which I have no hope of receiving in actuality (which was correct on the prior plots). The coloring for many LA stations, which I can easily receive are mostly in grey now as well.


The plot for Mystic, CT is more accurate, but it's probably about 20dB optimistic towards the Farmington (Hartford) stations.


Is the noise-margin figure assigning a penalty for Low-VHF?


I like the new look and though I liked the presence of the LOS column, it's omission should simply things for new viewers.


Another comment I have: Have you considered showing "ion" for ion stations? I remember being confused when I first used TV Fool if that also meant "independent."


Thank you for your continued efforts.
 

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The "noise margin" concept is interesting, and I think I like it once I'm convinced of the accuracy of the new calculations. I think some zero-based benchmark is a good idea if it's accurate.


Does a "zero" noise margin mean something marginally receivable with an antenna of zero gain? I note that I lock into several signals which have an NM of -3.5 to -9.6 with a 91XG and YA-1713 antenna, even before preamplification. Would it be correct to assume that adding the gain from these antennas to the NM results gives a mildly positive result, thus resulting in a solid picture? (And thus, a setup with a 15 dB gain antenna on a -15 NM station should provide the same results as a zero-gain antenna on a signal with a zero NM?)


I know it was mentioned that the dBm calculations have changed; many of mine show up as considerably stronger now by anywhere from 7 to 15 dBm.
 

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Mr. Lee,


I'm in agreement with a lot of the changes you made, and do think some of the rankings are more accurate. I love the idea behind the NM number, for certain. But something is definitely wrong.


My two strongest stations are WSLS-DT and WSET-DT. On the old plot for my coordinates, which I still have saved, they are shown as the powerful signals they are (WWCW is on an STA, so is actually much weaker than indicated), easily received with an indoor antenna even. On the new plot, WSET-DT actually has a negative NM number. WSLS-DT is just barely above positive. WVIR-DT is a 24/7 received station in reality, but has a negative number on the plot. WDRL-DT always has signal but is never actually decodable, but it's now way down at the bottom of the plot. I've attached the plots for comparison.


If it wasn't for the severe inaccuracy of the plots, I'd say I'd be able to get used to the changes. As it stands right now, I can't justify recommending TV Fool to people attempting to determine their coverage. I can only assume some kind of mistake was made somewhere in the calculation to cause such errors.


- Trip

 

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Quote:
Originally Posted by Falcon_77 /forum/post/14806111


Is the noise-margin figure assigning a penalty for Low-VHF?

Apparently it isn't, because my plot shows WBRA-DT as an easily receivable station.


- Trip
 

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I have a suggestion and a question. My eyesight isn't the greatest, which makes reading your charts difficult. A darker background color with white numbers would be easier for me I think, that's the suggestion. The question, with the new Noise Margin numbers, does +3db difference equal double the signal? Thanks for all of your efforts.
 

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Discussion Starter #275

Quote:
Originally Posted by Nitewatchman /forum/post/14782637


WWRD-LP (analog) is Currently shown in TVfool with their old ch 55 facilities.

This has been fixed. Yes, it was an outdated override. Thanks for the update!



Quote:
W66AQ Dayton is shown on 66. If I recall correctly, I think stations on ch 60~69 must vacate by analog shut off.

As for this station and other Class A and Low Power transmitters, the FCC has not offered much yet in terms of details for the transition. There are still several transmitters that show up in the upper UHF channels after the transition because there's no reliable data yet on exactly what will happen to these transmitters. I can only hope that the database will get updated soon with more useful information.


Quote:
The following are currently showing up in TVfool per info which matches Maximization "application" Data at TVquery rather than these stations current Post-transition CP's -- Maximization applications which have yet to be approved or denied or acted upon by FCC --Of course if these are approved at some point and become CP/CP Mod, these will be fine, but there is no indication presently, AFAIK whether they will or won't be approved.

TV Fool's software for snarfing the FCC database hasn't changed, but the FCC keeps making changes to the things they choose to include or what they mean.


I'm putting in a change to specially handle these post-transition applications that have not resulted in a CP MOD or LIC grant. Hopefully, this will clean up some of the phenomenon you're seeing with these maximization applications.



Quote:
Originally Posted by Digital Rules /forum/post/14805899


TV FOOL was 98% accurate for me before. Now stations that I never have, or never will get, rank ahead of stations that are 24/7; or frequently recievable at night. Has any real world testing been done? IMO, as it is now; it's pretty much useless.


"IF IT AIN'T BROKE, DON'T FIX IT"

I sympathize with your sentiment. As much as I would love to keep things the same, the FCC is constantly making changes to their database (like in the previous paragraph). I don't blame them since there's a lot of learning to do and more changes are sure to come before the transition date. We just need to do our part to try and keep up with the changes.


As for the layout and reporting style changes, these things have been a bit "broken" for a long time. Based on the various comments, questions, and topics of confusion that have been fed back to us, some of these changes were deemed necessary. Most people didn't have a big problem with the old format, but some people did, and we have to admit that certain parts were not as clear as they should be.



Quote:
Originally Posted by Falcon_77 /forum/post/14806111


My TV Fool plots are no longer accurate. It shows San Diego stations in the green, which I have no hope of receiving in actuality (which was correct on the prior plots). The coloring for many LA stations, which I can easily receive are mostly in grey now as well.


The plot for Mystic, CT is more accurate, but it's probably about 20dB optimistic towards the Farmington (Hartford) stations.

Could you please try again? The fixed FCC database interpretation may have something to do with this.



Quote:
Is the noise-margin figure assigning a penalty for Low-VHF?

No, because the analysis is done for signal strength "in the air". The VHF "penalty" that you're talking about is usually applied "after" this point to account for lower antenna gain, lower tuner sensitivity, and higher ambient noise at VHF. If you want to account for additional VHF signal loss for these factors, you need to subtract the appropriate values from the "starting" Noise Margin value to see what final NM you end up with at your receiver.


It is true that automatically including a frequency selective adjustment factor might provide a more "fair" comparison across all channels, but this really depends on each person's setup and link budget parameters across all channels. Diving into this next level of detail is opening up a huge can of worms which we're not ready to deal with yet.



Quote:
Another comment I have: Have you considered showing "ion" for ion stations? I remember being confused when I first used TV Fool if that also meant "independent."

I'll add this to the list of upcoming changes. I'll change all "i" references into "ION".




Best regards,

Andy
 

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Andy,


Any hope that in the future we can DL the station data in table format so I can put it in a spreadsheet and resort on specific columns?


I like the data, but I'd like to see it displayed via channel number, power level, asimuth, etc.


I was one of the folks that liked the now 'missing' columns.
It would be neat to see what antenna height at 0 NM would be.
 

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Discussion Starter #277

Quote:
Originally Posted by ziggy29 /forum/post/14806148


Does a "zero" noise margin mean something marginally receivable with an antenna of zero gain?

A zero NM means you'll just barely get reception if you have a 0 dBd gain antenna, zero cable / connection / splitter losses, and a receiver with a 0 dB noise figure.


In reality, you might start with a 0 dBd calibrated antenna, but you'd inevitably have some non-zero loss in the cable / connectors / impedance mismatch, and you'd have a receiver with a non-zero noise figure. For consumer-grade equipment, you're probably looking at 1-2 dB in the connections, and 6 dB in the tuner NF. You might need about 8 dB NM in the air to get this setup to work with your TV.


Alternatively, if you started with a 3 dB gain antenna and added a pre-amp with a 3 dB NF, then you'd be able to pick up channels down to 0 dB NM (assuming no loss between the antenna and pre-amp).


Yes, a 0 dB NM means you can decode the signal, but you must make sure you account for all the gains / losses that take place between the air and your signal decoder.


Quote:
I know it was mentioned that the dBm calculations have changed; many of mine show up as considerably stronger now by anywhere from 7 to 15 dBm.

Yes, the dBm values have changed. Most people should end up seeing about an 18 dB difference.
 

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Discussion Starter #278

Quote:
Originally Posted by Trip in VA /forum/post/14806184


I'm in agreement with a lot of the changes you made, and do think some of the rankings are more accurate. I love the idea behind the NM number, for certain. But something is definitely wrong.


My two strongest stations are WSLS-DT and WSET-DT. On the old plot for my coordinates, which I still have saved, they are shown as the powerful signals they are (WWCW is on an STA, so is actually much weaker than indicated), easily received with an indoor antenna even. On the new plot, WSET-DT actually has a negative NM number. WSLS-DT is just barely above positive. WVIR-DT is a 24/7 received station in reality, but has a negative number on the plot. WDRL-DT always has signal but is never actually decodable, but it's now way down at the bottom of the plot. I've attached the plots for comparison.

Hi Trip,


Could you please try again? I'd like to see if the latest FCC database fix is making any difference.


Thanks,

Andy
 

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My KTBC issue seems to be fixed. If the post-transition results are correct, I may be willing to experiment with a rotor...
 

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Quote:
Originally Posted by andy.s.lee /forum/post/14806748


Hi Trip,


Could you please try again? I'd like to see if the latest FCC database fix is making any difference.


Thanks,

Andy

No luck. Lists WVIR-DT as too low to receive, WSLS-DT and WSET-DT are both listed with negative numbers. It claims my most powerful station is the impossible to receive reliably WBRA-DT. You'll find it attached.


- Trip
 
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