KTVT-TV CURRENTLY ON 21-2

[Bob E. Nelson]

Quick! Take a look because it may only be transient.

I just did a fresh channel rescan and KTVT-TV is currently on 21-2, a subchannel of co-owned, co-located KTXA (RF-19). On the other hand, it may be a stopgap remedy by CBS to reach those viewers unable to capture the ``real'' KTVT signal on RF-11.

 

[Megapsycle]

Not receiving anything on 21-2.

 

[eskipper411]

getting 11 and 21-2 on air right now.

 

[Megapsycle]

Now it's there, KTVT 21.2 in 480i SD.

 

[Megapsycle]

Looks like it's official. From KTVT's website...

""Having trouble getting CBS 11 over the air after the digital switch? You can now watch CBS 11 on 21.2 on your converter box and HDTV, but you might have to re-scan to see it."

 

[X-Man]

I just noticed that yesterday when I rescaned my DTV converter.

 

[OnTexasTime]

Thanks for the tip, at least that is one more channel we can now pick up at the office.

 

[ropertex]

Going from 695 KW on Channel 19 to 23 KW on Channel 11 was a dumb move.

 

[JHBrandt]

Going from 695 KW on Channel 19 to 23 KW on Channel 11 was a dumb move.

Well, power levels aren't really comparable between VHF and UHF frequencies. At channel 11, the wavelength is 2.5 times longer than channel 19 and so diffracts much more readily around obstacles, so the signal can fill in "shadows" even at modest power levels.

Still, I think you're right that 23 kW is cutting things a bit thin. WFAA (8) is at 45 kW, and KFWD (9) will soon be at 55 kW. Elsewhere in north Texas, KLTV (7), in the Longview/Tyler area, is at 66 kW, and KXII (12), in the Texoma area, is 36 kW. So KTVT is definitely bringing up the rear, and with digital, even a few extra dB can sometimes make a big difference.

 

[arnoldevns]

Maybe JHBrandt can answer this question for me:

In analog TV broadcasting in North Texas (and I say that because I know it can be different in places like NY and LA - I'm using this market to make an apples to apples comparison), the standard maximum ERP for stations was:
100kw for low VHF (ch. 2-6)
316kw for high VHF (ch. 7-13)
and 5,000kw for UHF (ch. 14-69)

I know that 1,000kw is the max for UHF in digital, but it seems there is no coherent explanation of the power outputs for the digital VHF stations. Am I missing something? Is it different for each channel? What is the max?

 

[Bob E. Nelson]

Going from 695 KW on Channel 19 to 23 KW on Channel 11 was a dumb move.

Well, power levels aren't really comparable between VHF and UHF frequencies. At channel 11, the wavelength is 2.5 times longer than channel 19 and so diffracts much more readily around obstacles, so the signal can fill in "shadows" even at modest power levels.

Still, I think you're right that 23 kW is cutting things a bit thin. WFAA (RF-8) is at 45 kW, and KFWD (RF-9) will soon be at 55 kW. Elsewhere in north Texas, KLTV (RF-7), in the Longview/Tyler area, is at 66 kW, and KXII (RF-12), in the Texoma area, is 36 kW. So KTVT is definitely bringing up the rear, and with digital, even a few extra dB can sometimes make a big difference.

...and there's the situation with co-channel KSWO (RF-11) not too far away in Lawton/Wichita Falls with a modified CP for 138 kw (albeit from a stick at 1073' compared to KTVT's taller 1707' HAAT).

 

[JHBrandt]

Maybe JHBrandt can answer this question for me:

In analog TV broadcasting in North Texas (and I say that because I know it can be different in places like NY and LA - I'm using this market to make an apples to apples comparison), the standard maximum ERP for stations was:
100kw for low VHF (ch. 2-6)
316kw for high VHF (ch. 7-13)
and 5,000kw for UHF (ch. 14-69)

I know that 1,000kw is the max for UHF in digital, but it seems there is no coherent explanation of the power outputs for the digital VHF stations. Am I missing something? Is it different for each channel? What is the max?

I actually didn't know the answer to this. I know the limits for low power stations (15 kW UHF, 0.3 kW VHF), but the power levels for full-power VHF stations seem to be all over the map. The highest power stations I could find were one station at 45 kW in the VHF-Lo band and one at 160 kW in the VHF-Hi band.

Fortunately user w9wi on this board has posted the answer at http://boards.radio-info.com/smf/index.php?topic=147056.msg1240897#msg1240897 and, thanks to Google, I was able to find it. Turns out 45 kW and 160 kW are indeed the maximums, but almost no one is at or near those limits. Other factors, particularly co-channel interference on the crowded VHF-Hi band, apparently force stations like KTVT to operate well below the limits.

Why the few stations on VHF-Lo aren't mostly at the maximum is more of a mystery. I'd think the few stations still there would have little trouble with co-channel interference and would want the maximum power available, to give their viewers all the help they can.

 

[w9wi]

Maybe JHBrandt can answer this question for me:

In analog TV broadcasting in North Texas (and I say that because I know it can be different in places like NY and LA - I'm using this market to make an apples to apples comparison), the standard maximum ERP for stations was:
100kw for low VHF (ch. 2-6)
316kw for high VHF (ch. 7-13)
and 5,000kw for UHF (ch. 14-69)

I know that 1,000kw is the max for UHF in digital, but it seems there is no coherent explanation of the power outputs for the digital VHF stations. Am I missing something? Is it different for each channel? What is the max?

I actually didn't know the answer to this. I know the limits for low power stations (15 kW UHF, 0.3 kW VHF), but the power levels for full-power VHF stations seem to be all over the map. The highest power stations I could find were one station at 45 kW in the VHF-Lo band and one at 160 kW in the VHF-Hi band.

Fortunately user w9wi on this board has posted the answer at http://boards.radio-info.com/smf/index.php?topic=147056.msg1240897#msg1240897 and, thanks to Google, I was able to find it. Turns out 45 kW and 160 kW are indeed the maximums, but almost no one is at or near those limits. Other factors, particularly co-channel interference on the crowded VHF-Hi band, apparently force stations like KTVT to operate well below the limits.

Why the few stations on VHF-Lo aren't mostly at the maximum is more of a mystery. I'd think the few stations still there would have little trouble with co-channel interference and would want the maximum power available, to give their viewers all the help they can.

The 45kw limit applies only in Zones II and III. In Zone I (the northeast, as far west as Madison, Wis. and running south to the Ohio River) the limit is 10kw. In Zones II and III, in analog it was not necessary to derate power until you exceeded 600m in antenna height. In digital, power is derated after 305m. If KDFW, for example, had chosen to use DTV channel 4 with their old analog antenna at 511m, they would have been limited to about 15kw of power despite being in Zone II.

Power is also derated with height above 305m on high-band VHF. (and above 365m on UHF) At 521m, KTVT would be limited to 47kw. (they're actually authorized 23kw which suggests a limit due to interference rather than due to antenna height. I would imagine KSWO is most of the reason.)

 

[Bob E. Nelson]

...
At 521m, KTVT would be limited to 47kw. (they're actually authorized 23kw which suggests a limit due to interference rather than due to antenna height. I would imagine KSWO is most of the reason.)

KTVT will air most of the 2009 preseason Cowboys games. Combined with the higher than average over-the-air usage in D/FW (circa 20% per TopTechNews), will KTVT's current power be sufficient to reach that significant minority not using cable or satellite?

Since the DTV transition occurred during summer (reruns and other use of time beside television), the impact of not being able to capture a signal won't be known until ``must see TV'' arrives. In D/FW, that's on 13 AUG 2009 when KTVT airs the game against the Raiders.

 

[KERCAlum]

...
At 521m, KTVT would be limited to 47kw. (they're actually authorized 23kw which suggests a limit due to interference rather than due to antenna height. I would imagine KSWO is most of the reason.)

KTVT will air most of the 2009 preseason Cowboys games. Combined with the higher than average over-the-air usage in D/FW (circa 20% per TopTechNews), will KTVT's current power be sufficient to reach that significant minority not using cable or satellite?

Since the DTV transition occurred during summer (reruns and other use of time beside television), the impact of not being able to capture a signal won't be known until ``must see TV'' arrives. In D/FW, that's on 13 AUG 2009 when KTVT airs the game against the Raiders.

I will say that I can get KTVT with little problems using my Hauppage HVR-950Q USB ATSC tuner and a simple pair of rabbit ears (albeit "enhanced" with, of all things, about 10" of aluminum foil out by the tips) on my Acer laptop. The antenna is about 4' above the floor. Since we have AT&T U-Verse for our main TV, we haven't noticed any hiccups or problems with KTVT. When the DTV switch actually happened, though, there were some issues getting KTVT clearly (even now, on a scale of 0-35, my signal strength varies between 23 and 27). It's actually a bit ironic that I have more difficulty getting KTXA-DT/21-1 and KTVT-SD/21-2 than I do KTVT-DT/11.

As an aside, not that it matters (or maybe it does) I've noticed the KTVT signal appears to "smear" a bit more in moving scenes than does KDFW-DT/4-1 (RF 35). In fact, the KDFW signal is almost creepily clear (I didn't know Steve Eager had so much hair on his ears!). Any ideas as to why that is? Is there more compression and/or less enhancement being used on KTVT's signal than on KDFW's?

 

[JHBrandt]

...
At 521m, KTVT would be limited to 47kw. (they're actually authorized 23kw which suggests a limit due to interference rather than due to antenna height. I would imagine KSWO is most of the reason.)

KTVT will air most of the 2009 preseason Cowboys games. Combined with the higher than average over-the-air usage in D/FW (circa 20% per TopTechNews), will KTVT's current power be sufficient to reach that significant minority not using cable or satellite?

Since the DTV transition occurred during summer (reruns and other use of time beside television), the impact of not being able to capture a signal won't be known until ``must see TV'' arrives. In D/FW, that's on 13 AUG 2009 when KTVT airs the game against the Raiders.

My understanding is that for long-distance reception, antenna height is more important than power, assuming the FCC's derating rules aren't unreasonable. I suppose that explains why I could only find a couple of VHF stations at the absolute limit: most have chosen higher antennas over higher power.

I haven't had much trouble receiving KTVT on VHF, but there was a hiccup last Wednesday when it wouldn't come in at all.

Fortunately, KXII happened to be quite strong that evening, so I could watch CBS there. But had it been KTVT-only programming like the upcoming football games, I would've had to rely on 21.2 at standard definition.

I don't really mind losing HD as long as it doesn't happen often, but one thing I do wish KTVT and KTXA would work out is getting the electronic program guide working on 21.2. Right now it just shows "DTV Program," but there's no reason 21.2 can't show the same program guide as 11.1.

 

[Radio3787]

That's really smart because I know when I used to live in Denton I could get KTXA 21 over the air but not KTVT 11.

 

[w9wi]

My understanding is that for long-distance reception, antenna height is more important than power, assuming the FCC's derating rules aren't unreasonable. I suppose that explains why I could only find a couple of VHF stations at the absolute limit: most have chosen higher antennas over higher power.

I think there's a mix of issues there. The antenna height thing is certainly the case, but also there was the need to avoid interference with analog stations on the same/adjacent channels.

That need goes away at midnight tonight (if it hasn't already, depending on station) but stations do have to request the available power increase. Some may not due to the expense of following through.

I don't really mind losing HD as long as it doesn't happen often, but one thing I do wish KTVT and KTXA would work out is getting the electronic program guide working on 21.2. Right now it just shows "DTV Program," but there's no reason 21.2 can't show the same program guide as 11.1.

Some believe an accurate program guide is a FCC requirement, through the reference of the ATSC standard.

 

[JHBrandt]

I think there's a mix of issues there. The antenna height thing is certainly the case, but also there was the need to avoid interference with analog stations on the same/adjacent channels.

That need goes away at midnight tonight (if it hasn't already, depending on station) but stations do have to request the available power increase. Some may not due to the expense of following through.

I just looked at the FCC's TV query and found only one station (KVVU in Henderson, Nevada) which has applied for maximum power with a tower over 305 m HAAT. The FCC hasn't been keeping their TV query database up-to-date, though, so that may not mean very much.

 

[LibertyNT]

...
At 521m, KTVT would be limited to 47kw. (they're actually authorized 23kw which suggests a limit due to interference rather than due to antenna height. I would imagine KSWO is most of the reason.)

KTVT will air most of the 2009 preseason Cowboys games. Combined with the higher than average over-the-air usage in D/FW (circa 20% per TopTechNews), will KTVT's current power be sufficient to reach that significant minority not using cable or satellite?

Since the DTV transition occurred during summer (reruns and other use of time beside television), the impact of not being able to capture a signal won't be known until ``must see TV'' arrives. In D/FW, that's on 13 AUG 2009 when KTVT airs the game against the Raiders.

My understanding is that for long-distance reception, antenna height is more important than power, assuming the FCC's derating rules aren't unreasonable. I suppose that explains why I could only find a couple of VHF stations at the absolute limit: most have chosen higher antennas over higher power.

I haven't had much trouble receiving KTVT on VHF, but there was a hiccup last Wednesday when it wouldn't come in at all.

Fortunately, KXII happened to be quite strong that evening, so I could watch CBS there. But had it been KTVT-only programming like the upcoming football games, I would've had to rely on 21.2 at standard definition.

I don't really mind losing HD as long as it doesn't happen often, but one thing I do wish KTVT and KTXA would work out is getting the electronic program guide working on 21.2. Right now it just shows "DTV Program," but there's no reason 21.2 can't show the same program guide as 11.1.

Ive always found the KXII Deal a little bit funny. at night KXII will Boom into Wylie and i can watch that. But up here in McKinney not as often. infact. ive never really been able to watch KXII in McKinney.
As For CBS 11. I went without CBS programming for about a week until i found 21.2.