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Old 02-28-2008, 10:48 AM
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I've got a wired problem with Google Earth, if I select a station the "TX maps On/Off" signal pattern, that station does not line up with the transmitter site. It looks like only one signal pattern is selected. No matter what station you choose from the list below. I've tried several different metro areas, including downloading older versions of Google Earth, currently running 4.0.2722. Also tried the newest beta version on Google. Any help would be great.

Also, I noticed that if I type in a station using the on-line coverage map, the list seems more comprehensive, including stations that are not in current KMZ files. Will those stations be added soon? The stations I'm looking at are 200 miles from any nearest metro areas available for download. Thanks.
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Old 02-28-2008, 03:17 PM - Thread Starter
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Quote:
Originally Posted by mdamberger View Post

I've got a wired problem with Google Earth, if I select a station the "TX maps On/Off" signal pattern, that station does not line up with the transmitter site. It looks like only one signal pattern is selected. No matter what station you choose from the list below. I've tried several different metro areas, including downloading older versions of Google Earth, currently running 4.0.2722. Also tried the newest beta version on Google. Any help would be great.

Have you expanded the list of coverage maps underneath "TX maps On/Off"? If you click on the "+" to the left of that folder name, you should see an expanded list of all the coverage maps contained in that set. The list is initially collapsed, so you need to hit the "+" to expand it.

Once that list is visible, you can select any one of the individual coverage maps listed by clicking on the circle to the left of its name.

For more detailed instructions, you can look at the help available here.

I hope that helps.

Quote:


Also, I noticed that if I type in a station using the on-line coverage map, the list seems more comprehensive, including stations that are not in current KMZ files. Will those stations be added soon? The stations I'm looking at are 200 miles from any nearest metro areas available for download. Thanks.

It's true that the online maps cover many more transmitters than the ones availabed in the downloadable KMZ packages. The hope is to work in a way to include all the same coverage maps in both formats, but that's not possible right now.

The downloadable content is much higher resolution and much larger in terms of file size. There's a bit of a logistical problem in hosting the many tens of gigabytes necessary to include all coverage maps in a high resolution format.

Best regards,
Andy
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Old 02-28-2008, 08:57 PM
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Quote:
Originally Posted by andy.s.lee View Post

Have you expanded the list of coverage maps underneath "TX maps On/Off"? If you click on the "+" to the left of that folder name, you should see an expanded list of all the coverage maps contained in that set. The list is initially collapsed, so you need to hit the "+" to expand it.

Once that list is visible, you can select any one of the individual coverage maps listed by clicking on the circle to the left of its name.
Andy

I can see the individual call signs, both digital and analog. I first unchecked both lists, then I choose one call sign. Then check "TX maps On/Off". I then see the signal pattern overlay-ed. But it clearly does not belong to the station I chose, since the icon for the station does not match up with the signal pattern. If I choose another station, I still get the same signal patter overlay, it does not move or change location. If use the on-line version, it shows the proper signal pattern lined up with the right station. Analog, or digital, it does not change. The only difference is if I open up a different KMZ package, then I see the same problem all over again, just a different area.


Quote:
Originally Posted by andy.s.lee View Post

It's true that the on line maps cover many more transmitters than the ones available in the downloadable KMZ packages. The hope is to work in a way to include all the same coverage maps in both formats, but that's not possible right now.
Andy

Would it be possible to expand the coverage to 300 miles out from the center of the KMZ package? In S.E. New Mexico, there is a hole that no adjacent markets is near enough to show the full power stations. Only a few outlying stations, along the border with Texas. Maybe just do this for the western interior states, since distances between markets is much greater then back east.

I've tried several versions of Google Earth, they all get the same results. Thanks for any assistance.
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Old 02-29-2008, 12:02 AM - Thread Starter
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Quote:
Originally Posted by mdamberger View Post

I can see the individual call signs, both digital and analog. I first unchecked both lists, then I choose one call sign. Then check "TX maps On/Off". I then see the signal pattern overlay-ed. But it clearly does not belong to the station I chose, since the icon for the station does not match up with the signal pattern. If I choose another station, I still get the same signal patter overlay, it does not move or change location. If use the on-line version, it shows the proper signal pattern lined up with the right station. Analog, or digital, it does not change. The only difference is if I open up a different KMZ package, then I see the same problem all over again, just a different area.

Quote:


I've tried several versions of Google Earth, they all get the same results. Thanks for any assistance.

If you look to the left of "Tx maps On/Off", there is actually a small "+" sign next to the checkbox (look all the way to the left of that row). This "+" sign lets you expand the folder revealing all the different coverage maps that are available. Look closely for the "+" sign so that you can expand the list that is currently hidden from view. If you can't see all the way to the left side, you may need to use the scrollbar at the bottom to make sure you're seeing all the way to the left edge.

The online FAQ, available here, has some screen shots to help guide you.

The transmitter icons are in one folder (with "Digital" and "Analog" subfolders beneath it) and the Tx maps is another separate folder above that. Both of them contain a list of detailed content for each of the transmitters. Make sure all the folders are fully expanded so that you may view their content.

When you simply check the box next to "Tx maps On/Off", it is only displaying the coverage map for the first callsign in its list. The coverage maps being displayed can be selected independently of which transmitter icons are active. If you fully expand the coverage map list, you can see all the callsigns available and then individually select the one you wish to see.

This is not a problem with the version of Google Earth you are using. The files have been tested with versions 4.0 through the latest 4.2.x beta. They should all function about the same. It's merely a matter of making sure you expand the folder to show you the complete list of coverage maps.

I hope that helps!


Quote:


Would it be possible to expand the coverage to 300 miles out from the center of the KMZ package? In S.E. New Mexico, there is a hole that no adjacent markets is near enough to show the full power stations. Only a few outlying stations, along the border with Texas. Maybe just do this for the western interior states, since distances between markets is much greater then back east.

I realize that there are a lot more coverage maps people want to see in Google Earth. There's a serious amount of processing and packaging going on to generate the current collection of files. This already amounts to over 13 GB of data at maximum compression. Expanding the sets to include all transmitters, even if done very efficiently, would increase the data set by a factor of 5-10. There's a hell of a lot of TV transmitters out there and we're not set up (yet) to handle that much of a data load.

I'm sorry that I don't have any better news to offer at this point.

Best regards,
Andy
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Old 02-29-2008, 11:16 AM
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Quote:
Originally Posted by andy.s.lee View Post

If you look to the left of "Tx maps On/Off", there is actually a small "+" sign next to the checkbox (look all the way to the left of that row). This "+" sign lets you expand the folder revealing all the different coverage maps that are available. Look closely for the "+" sign so that you can expand the list that is currently hidden from view.

When you simply check the box next to "Tx maps On/Off", it is only displaying the coverage map for the first callsign in its list. The coverage maps being displayed can be selected independently of which transmitter icons are active. I hope that helps!
Andy

Thanks so much, that was it. For whatever reason I just did not see that on the left side. Doh!

Quote:
Originally Posted by andy.s.lee View Post

I realize that there are a lot more coverage maps people want to see in Google Earth. There's a serious amount of processing and packaging going on to generate the current collection of files. This already amounts to over 13 GB of data at maximum compression. Expanding the sets to include all transmitters, even if done very efficiently, would increase the data set by a factor of 5-10. There's a hell of a lot of TV transmitters out there and we're not set up (yet) to handle that much of a data load.

I'm sorry that I don't have any better news to offer at this point.

Best regards,
Andy

Thanks for the effort on this all, it's been a tremendous contribution! I look forward to when you can offer more markets via Google Earth. Tell then I'll use the on line coverage maps for my local area. Keep it up!

P.S. I've told so many people about this site, since I work in TV. They are blown away by its innovation.
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Old 04-25-2008, 03:41 AM - Thread Starter
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The post-transition part of the Signal Analysis Tool at tvfool has been updated to include the new Final DTV Allotment list (FCC-08-72A2.pdf), released by the FCC on March 6, 2008.

Best regards,
Andy
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Old 04-25-2008, 08:19 AM
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Quote:
Originally Posted by andy.s.lee View Post

The post-transition part of the Signal Analysis Tool at tvfool has been updated to include the new Final DTV Allotment list (FCC-08-72A2.pdf), released by the FCC on March 6, 2008.

Best regards,
Andy

Nice touch, thanks.

It appears that the 2009 data is also appearing in the current database selection.
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Old 04-25-2008, 09:28 AM
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Originally Posted by andy.s.lee View Post


If the antenna radiation pattern (polar plot) is known, we can imagine that pattern overlaid on the radar plot to roughly know whether the beam width is too wide/narrow to capture signals from multiple tower clusters.

Are there plots available on line somewhere for various antennas? Specifically, I've got a CM2030 and would like to know the specific channel gain for the azimuth data I get from TVFool.
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Old 04-25-2008, 02:21 PM
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Originally Posted by MikeBiker View Post

Are there plots available on line somewhere for various antennas? Specifically, I've got a CM2030 and would like to know the specific channel gain for the azimuth data I get from TVFool.

Winegard typically publishes a spec sheet with polar plots, F/B ratios, gain on specific channels/etc, but I don't think CM does. There are polar, and gain plots available for many models of antennas here :

http://www.hdtvprimer.com/ANTENNAS/comparing.html

Assume that might be a typo, and you perhaps meant CM3020 -- While that one specifically isn't on that site, but there is a polar plot for CM3018 here :

http://www.hdtvprimer.com/ANTENNAS/cm3018.html

Jeff
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Old 04-25-2008, 03:11 PM
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Jeff,

Thanks for the links. Yes, that was a typo. The second link was what I was looking for. I wanted to know the relative drop off in gain with various off axis stations and that page gives me what I need.
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Old 04-25-2008, 03:46 PM
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Quote:
Originally Posted by Tower Guy View Post

It appears that the 2009 data is also appearing in the current database selection.

I can confirm that KABC and KTTV are showing their post-transition channels on both the current and post-transition results. I will check additional markets later.

In general, the TV Fool database seems to count CP's as active stations and since the post-transition CP grants are flowing in, it may be hard to separate the two going forward.
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Old 04-25-2008, 03:58 PM - Thread Starter
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Quote:
Originally Posted by Tower Guy View Post

It appears that the 2009 data is also appearing in the current database selection.

Quote:
Originally Posted by Falcon_77 View Post

I can confirm that KABC and KTTV are showing their post-transition channels on both the current and post-transition results. I will check additional markets later.

In general, the TV Fool database seems to count CP's as active stations and since the post-transition CP grants are flowing in, it may be hard to separate the two going forward.

If that is true, then perhaps the best thing to do is back-up the pre-transition analysis data set to an older snapshot of the FCC database. I think that the snapshots from last February may be suitable since it did not yet include many of the CP updates.

Best regards,
Andy
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Old 04-25-2008, 04:26 PM
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Could be wrong, but involving the process regarding 3rd DTV review/form 387 filings/etc, I don't think there would be any post-transition CP's for stations changing channel assignments before Feb 2008 (probably march, really) ... Thus I think for the "current" database info (from Feb 2008) used immediately prior to this last update would probably be fine to "go back to", along with manual overrides/etc. andy had already done for individual cases where the FCC info was wrong/had outdated STA's/etc .... FWIW, regarding that Last time I looked at it, several weeks ago anyway, all was well here regarding the digital station info ....

Anyhow --- Just ran the plots for my location, and regarding the "current" plots :

WKRC-DT still shows up on their current digital channel, although they've already been granted CP for post-transition on 12 .... However, I think Andy manually adjusted the database for this one, regarding a STA that was "out of date" ....

WPTD-DT is shown in the current plot on their post-transition channel (16 - they were granted a CP for it last month), but they're on 58 currently ....

WBDT-DT, the other station in my area that is moving, has yet to file for a post-transition CP, thus they are still shown with their current channel assignment/facility ...

Jeff
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Old 04-25-2008, 05:45 PM - Thread Starter
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OK. Pre-transition analysis is now set to use a February snapshot of the FCC data. Post-transition analysis is using the March 6 data.

If anyone notices any problems, please let me know.

Best regards,
Andy
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Old 04-25-2008, 06:59 PM
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Quote:
Originally Posted by andy.s.lee View Post

OK. Pre-transition analysis is now set to use a February snapshot of the FCC data. Post-transition analysis is using the March 6 data.

If anyone notices any problems, please let me know.

Best regards,
Andy

The pre-transition channels appear correct again.

For awhile today the post-transition data indicated ERPs from CPs issued since the table was released. Any chance that data set is coming back?
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Old 04-25-2008, 07:19 PM - Thread Starter
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Originally Posted by Tower Guy View Post

For awhile today the post-transition data indicated ERPs from CPs issued since the table was released. Any chance that data set is coming back?

Do you believe those CP records to be the best ones to use? If so, I can certainly make them the default for just the post-transition analysis.

Best regards,
Andy
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Old 04-25-2008, 08:57 PM
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Quote:
Originally Posted by andy.s.lee View Post

Do you believe those CP records to be the best ones to use? If so, I can certainly make them the default for just the post-transition analysis.

I think the granted CP's are more accurate than Appendix B will ever be for post-transition. Appendix B seems to be full of assumptions that won't make it to the real world. While updating my spreadsheet, I have noticed about 75% of the granted CP's have significant deviations from the Appendix B allotment, especially for commercial stations.

The pre-transition results appear to be in order again. Thank you.
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Old 04-26-2008, 08:46 AM
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Quote:
Originally Posted by andy.s.lee View Post

Do you believe those CP records to be the best ones to use? If so, I can certainly make them the default for just the post-transition analysis.

Best regards,
Andy

The CP's are the facilities that the stations have told the FCC that they would like to build and the FCC has agreed to that configuration. In many cases they are omnidirectional antennas where the table showed directional.

The FCC allowed minor changes as long as they did not cause more than .5% additional interference and the contour did not extend by more than 5 miles.

The CPs are more up to date than the DTV table.
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Old 06-26-2008, 08:33 AM
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Andy;

Will FM Fool display anticpated signal reception, as TV Fool does, based on a specific address or LAT/LON?

thanks,
Kelly
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Old 06-26-2008, 09:10 AM - Thread Starter
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Originally Posted by KBoswell View Post

Andy;

Will FM Fool display anticpated signal reception, as TV Fool does, based on a specific address or LAT/LON?

thanks,
Kelly

Yes.

It's actually close to getting done. There have been many updates underway affecting both TV Fool and FM Fool because of changes in the FCC's database. They've introduced a number of new database fields relating to the pre-transition to post-transition changes in effect, and this has required a bit of re-work to take advantage of this new information. I hope this will provide more timely updates as we get closer to February 17, but there's always the possibility that the FCC database will contain errors. We shall see...

Many of the tools for both web sites are built upon a common collection of software building blocks, so the FM Fool tools are pending the successful update of the FCC database routines.

I expect to roll some software updates to the sites in the next couple of weeks. Once the sites have been updated, I'll look at everyone's feedback to see how well the new databases holds up.

Best regards,
Andy
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Old 06-26-2008, 11:51 AM
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Quote:
Originally Posted by andy.s.lee View Post

I expect to roll some software updates to the sites in the next couple of weeks. Once the sites have been updated, I'll look at everyone's feedback to see how well the new databases holds up.

Best regards,
Andy

Woo-Hoo! It'll be nice to see the effect of the DTV maximization applications that were posted yesterday.
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Old 06-26-2008, 06:38 PM
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Woot!!! FM Fool. I can't wait. This has been long overdue in the FM-DX world.

Just a suggestion: you might want to add in RDS and HD Radio data (eventually, of course).

Thanks again for your wonderful resource!!!!
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Old 06-26-2008, 09:37 PM
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What sort of noise model/assumptions are used for TV & FM in VHF band?
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Old 06-28-2008, 05:21 AM - Thread Starter
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A number of changes have been made to the Signal Analysis Tool today. There are some significant changes to the visual appearance of the reports, but the real important changes are actually under-the-hood in the way the tool loads and processes the FCC database. The highlights of the changes are as follows:
  • FCC database extraction now tries to interpret the new DTV transition fields that were recently added. This will hopefully provide more accurate and timely updates as broadcasters work toward the February 17 transition date. We'll see how well the FCC can keep this information up to date...
  • FM broadcasts are also tested when checking for adjacent channel interference next to channel 6 (thanks to the work from FM Fool). Testing of FM signal strength for pre-amp overload issues is not there yet, but we'll probably add that at some point in the future.
  • The bars on the radar plot have been "reversed". This alternate presentation was considered over two years ago, but since a few users have suggested the same idea, we thought we'd try it out. For some people, this might be more intuitive since it gives the appearance of signal strength emanating from the horizon. Feedback is welcome.
  • Channel numbering on the plot has been spaced apart a bit. There's no perfect solution for the cases where there are just way too many channels to display, but this layout should help most people see more of the channel numbers clearly.
  • VHF channels are now drawn with extra emphasis (thicker, with a yellow outline) in both the radar plot and the spectrum plot (bottom graph). VHF antennas are distinctly different from UHF antennas, with special consideration needed when planning an installation (antenna type, pointing, mounting configuration, pre-amp type, etc.). We hope this representation will help draw attention to those channels that need it.

I hope you enjoy the changes.

Best regards,
Andy
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Old 06-28-2008, 06:23 AM
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Quote:
Originally Posted by andy.s.lee View Post

A number of changes have been made to the Signal Analysis Tool today.

1. I love the new radar plot.

2. Some stations are missing. In Albany NY; WXXA and WRGB are not shown on the current database. They show up properly on the February 2009 display. I don't see a pattern, WXXA is staying on channel 7, WRGB is changing to channel 6.
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Old 06-28-2008, 06:28 AM - Thread Starter
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Quote:
Originally Posted by holl_ands View Post

What sort of noise model/assumptions are used for TV & FM in VHF band?

Noise, interference, multipath, and other things that reduce usable SNR are not part of any assumptions in the models. The Rx_dBm values in the reports represent the signal power of the broadcast at a point in space (some people like to think in terms of power, others like to use field strength). The broadcaster's ERP, antenna pattern, and Longley-Rice propagation model determine what that value will be. Local noise in the VHF band might have an effect on SNR, but the dBm available from the broadcaster remains the same.

I agree that there are a lot of very important factors to consider to ultimately determine receivability of a channel. Antenna gain, impedance matching, pre-amp noise figure, environmental noise floor, burst noise, multipath, Doppler, fading, and tons of other site-specific details need to be known in order to provide a more complete link budget picture.

Anyone with enough knowledge of their system to understand all the different elements in the link budget can apply those adjustments on top of the Longley-Rice model results. The average consumer is not going to know any of this, so they will have to just go with very broad rule-of-thumb estimates.

BTW, in a few places, the FCC uses "adjusted" Longley-Rice models based on USGS land-use codes. The intent was to take into account different amounts of signal impairment (multipath, interference, etc.) based on the user's location (urban, suburban, rural, open space, etc.). In my experience, this has never been very accurate. These "automatic assumptions" tend to add more confusion rather than real accuracy because the land use data is not precise nor detailed enough. You often end up with more exceptions to the rule rather than uniform behavioral trends.

Best regards,
Andy
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Old 06-28-2008, 07:14 AM - Thread Starter
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Quote:
Originally Posted by Tower Guy View Post

2. Some stations are missing. In Albany NY; WXXA and WRGB are not shown on the current database. They show up properly on the February 2009 display. I don't see a pattern, WXXA is staying on channel 7, WRGB is changing to channel 6.

OK. Found a very subtle bug in the way the pre/post transition status was being read. This should be fixed now. Thanks for noticing it!

Best regards,
Andy
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Old 06-28-2008, 08:48 AM
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I like the new radar plot as well. It is much easier to see where the weak stations are coming from. Previously they were all crammed in the center and could not be distinguished (at least on the radar plot).

As for the VHF stations, I didn't notice the yellow until I read your comments.

One minor issue I saw was that WTXX shows 12 for post-transition operations when they will be on 20.

How are you handling the application filings? I noticed that WNAC is showing the 30kW ND antenna that they want, while WPRI still shows the existing 18kW license (they also requested 30kW).

Thank you for your continued efforts.
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Old 06-28-2008, 12:19 PM
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Test entry: Zip = 19067, Antenna height = 25 feet above local terrain.

Three of the four NJ digital channels don't have the "-DT" designator after them- WNJT, WNJS, WNJU. WNJB-DT looks OK.

Checking post-transition, I thought that Philly local WHYY-DT and WPVI-DT were going to occupy their old analog slots (WHYY to channel 12, WPVI to channel 6)? They're showing on existing UHF channels. Discussed in the Philly OTA thread: http://www.avsforum.com/avs-vb/showp...postcount=1335

Checking the FM side, it was nice to see for the first time how freaking strong WPST is. I'm about 2-3 miles LOS to the transmitter. The next closest station is 15 dB down. Good stuff.

Now, for the new radar plots. I was having a hard time trying to understand your new layout. When I looked at the FM plot, I finally figured it out.

You mean that the lowest signal level is on the outside ring, IOW it's the farthest away / harder to get. The strongest signal is at the center of the "target", IOW close and easy to get.

The FM bars are nice and easy to read with no channel numbers (station IDs). That's in comparison to the TV bars, which are extremely difficult to read when you are in a crowded metro location.

Here's my suggestions for your radar plots:
- Either change the multi-colored pastel outer ring to light gray or drop it entirely. Very confusing as it doesn't add any value to the other colors.
- Color the center target area green instead of white. I was looking for what white meant, but it really means green.
- Change the TV radar plot to match your FM radar plot. I like the solid blue bar with no channel numbers. Very easy to interpret. I can just read the table for the details.

Suggestion for your TV chart:
- Change the table color format to match your FM chart. The blue is very nice to read (all items for Channel, Signal, Distance). Besides, TV and FM should match formats to avoid reader confusion.

Suggestion for your analysis text:
Give your readers some help on how to interpret the radar plot. Change "Longer bars represent stronger signals." to:

"The bars represent signals you can receive. The strongest signals are closest to the center of the "target" (where you are), while the weakest ones are at the edge and are harder to receive."
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Old 06-28-2008, 12:37 PM
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Quote:
Originally Posted by andy.s.lee View Post

[*]FM broadcasts are also tested when checking for adjacent channel interference next to channel 6 (thanks to the work from FM Fool). Testing of FM signal strength for pre-amp overload issues is not there yet, but we'll probably add that at some point in the future.

Andy,

I'm somewhat confused on what the effects the transition will have to my FM receiver. Here in Philly, channel 6 has been a life-long "companion" on my FM radio at 87.9 FM. With the transition to ATSC, that's going to change. (See my previous post about WPVI retaining channel 6 after the transition.)

Understood that it's going to be nothing more than receiver desensitization from the FM perspective. However, what does the ATSC Channel 6 RF spectral emission look like? I'm concerned about additional frequency content that may step on channels higher than 87.9 FM. Is this a valid concern? Do you need to be concerned with C/N for an FM discriminator? Interesting problem.
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