: Global Ottawa DTV Transition - Aug. 16, 2011 - update in Post #331


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Jake
2011-08-24, 11:56 AM
Thanks for the link Trip. I poked around and pulled this up to help me assess my future OTA requirements for Channel 6 in Ottawa.

Here is the direct link to the source refered to in post 299.
http://www.rabbitears.info/contour.php?appid=1283204&map=Y

Trip
2011-08-24, 12:03 PM
Thanks for the link Trip. I poked around and pulled this up to help me assess my future OTA requirements for Channel 6 in Ottawa.

Here is the direct link to the source refered to in post 299.
http://www.rabbitears.info/contour.php?appid=1283204&map=Y

Side note, if you want to get rid of the red and blue contour lines, add &contour=N to the end of the address. One of these days, I'm going to add a link for that feature plus some other things that I've been meaning to add to that page. :)

- Trip

Jake
2011-08-24, 12:07 PM
OK thanks. CH6 is not looking good for me. I am in a yellow area and lots of red pockets around me. I am only 10km away too!

stampeder
2011-08-24, 12:16 PM
TVFOOL is definatly taking terain into consideration when reporting the effective ERP (adjusted according to your location)I wish TVFool would use a term like "calculated field strength" for that type of estimate instead of ERP. Now we unfortunately have a widespread misuse and misunderstanding of that term. :rolleyes:

GeoStar
2011-08-24, 12:21 PM
warning snide comments follow:
( paid shills should avert their eyes)

My neighbour agrees with old sparks ... about service

CIII needs to migrate to a UHF channel if they really want to serve the City of Ottawa as well as Gatineau to their respective borders. This should be a minimum mandatory requirement...

according to her ....
The CRTC should look at such corporate 0.4 watt power TEASeR high jinx as not serving the community! ---and even shut down such obvious bait for cable , trickery , either you serve the public or you don't , its not just for corporate profit ...

wow eh?
hey maybe she is wrong and it is , only the CRTC knows for sure...hahah

Then again when cable breaks down they can up the signal for a few hours to meet the regulations as the industry and other er ... self regulating companies have set them out---------- hahahahah :eek:

tvlurker
2011-08-24, 01:12 PM
I wish TVFool would use a term like "calculated field strength" for that type of estimate instead of ERP. Now we unfortunately have a widespread misuse and misunderstanding of that term. :rolleyes:
Because it's not the calculated field strength. The calculated field strength would diminish along the radial, and vary with terrain. The effective power does not.

Dave Loudin
2011-08-24, 02:14 PM
TVFOOL is definatly taking terain into consideration when reporting the effective ERP (adjusted according to your location)


There's no way that this can be correct. As stated before, ERP is Transmitter Power times Transmit Antenna Gain (Don't forget that antenna gain varies by azimuth with directional antennas.) It is a quality of the transmit site.

roger1818
2011-08-24, 02:47 PM
Let me throw my hat in the ring on the ERP issue. TVFool lists two (2) types of ERP (maximum and effective).

The "Maximum ERP" is what stampeder is describing, the maximum power transmitted from the antenna.

The "Effective ERP" is the amount of power transmitted towards you. For a non-directional transmission, this will be the same as the "Maximum ERP," otherwise it will be less than or equal to the "Maximum ERP."

Neither of these values take terrain or dispersion into account, thus while interesting, they aren't of much use.

Much more useful are the "Predicted signal power and the Noise Margin (NM)" and of these the NM is the most user friendly.

flavoie
2011-08-24, 03:05 PM
Tried Global from my Sony xbr4. I had only tried from PC tuners before. My Sony picks up less channels than my 950Q and even does not finish a digital scan properly. The only way I saw some digital channels was when tuning them manually.

So... Still no Global Ottawa for me regardless of tuner type.

roger1818
2011-08-24, 03:45 PM
I poked around and pulled this up to help me assess my future OTA requirements for Channel 6 in Ottawa.

Here is the direct link to the source refered to in post 299.
http://www.rabbitears.info/contour.php?appid=1283204&map=Y

This map looks extremely optimistic to me. According to Global's application Stittsville was outside the urban contour but it is well within the red contour on this map. My difficulties makes me trust Global more than rabbitears.

Trip
2011-08-24, 04:13 PM
The red and blue lines are generated using the FCC's coverage contour method. It's not known for its amazing accuracy.

(The reason I started generating Longley-Rice maps in the first place was to demonstrate how inaccurate the FCC's contour lines were. Go figure. :) )

- Trip

tvlurker
2011-08-24, 04:18 PM
Remember that table-driven contour lines were established back before you could do L-R simulations on your home PC.

Also, don't forget that the contour lines are based on a limited number of EHAAT radials, that can be selected for whatever advantage necessary, and only cover the terrain within 10 miles of the transmitter site.

Global's channel 6 transmitter was a short-spaced infill station established in the early eighties, back when there were no commercial stations on UHF in Eastern Ontario.

Now that cable is widespread, my cynical side says that coverage contours (and OTA in general) exist only to establish cable priority carriage footprint.

Dave Loudin
2011-08-24, 04:30 PM
Thanks, tvlurker, for summing that up. These contour lines can be best viewed in my mind as allocation tools, not assessments of coverage at an individual location. I know that's the point I was trying to make with Trip when we've discussed this in the past.

guigz
2011-08-24, 08:54 PM
So I get 2.474 KW effective ERP at my place.

Does that mean I should be able to get Global? So far I have no luck with my CM 4228 and my cm 7777.

From my limited understanding, my antenna is not able to capture channel 6 due to it not being large enough. Is this so?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9e74dbb7cb3abb

micah
2011-08-24, 09:23 PM
Yeah. 4228 isn't going to cut it. You need something with VHF-LO! Those are the _big_ antennas.

charettepa
2011-08-24, 09:29 PM
I know it sounds strange
but so far this is working great

use rabbit ears
spread them out to 34.5" each side
put about 3-4" of tape at each split/joint
this way the length cannot change
for me it only works outside but it does work

mike infinity
2011-08-24, 10:09 PM
Well I am now receiving global...mapped to 4.1 by wmc all of a sudden and cbc has been displaced as of right now.

I tossed a vip-302sr up into my attic and roughly pointed to CF (the antenna is not even close to level). The signal is at 80% with a rare glitch in the stream.

It looks like I will be able to get it no trouble with vip-302sr in attic....I retired my rabbit ears from the roof.

charettepa
2011-08-24, 10:23 PM
oh i wish a 302 would fit in my attic
small attic trusses very close to each other

mike infinity
2011-08-25, 07:31 AM
I went back to the attic to fine tune the antenna placement...oddly,,just sitting on the insulation works best and tilted off-level pointing toward cf. I get rare frame drops but otherwise clear.

Fota
2011-08-25, 09:11 AM
Now that cable is widespread, my cynical side says that coverage contours (and OTA in general) exist only to establish cable priority carriage footprint.That's what I'm wondering... can you really get a license for a local broadcast station and only pump out a few watts on VHF-lo and instantly expect full regional BDU carriage regardless??
And, if not, can Global TV be pushed (via CRTC) to take action (higher power and move to UHF) based on this?
Not to mention Global TV is probably claiming to advertisers viewership numbers including regional OTA users.