AVS Forum banner

15461 - 15480 of 15503 Posts

·
Registered
Joined
·
17,298 Posts
Thanks to both for the VHF explanation.

Now, since you are both wise in the ways of science, I have another question. I understand the economic benefits of broadcasting in VHF vs UHF since you need less power in the VHF spectrum. For example, WMAR (UHF) transmits with 830kw while both WBAL/WJZ transmit with 30kw. So, I would think that, at least theoretically, VHF can transmit at a higher power than 30kw.

Now, I live roughly 55 miles from the TV hill towers, and can get the UHF stations, but not the VHF ones. I'm guessing that there are a sizable number of folks in the same situation throughout the U.S., and further, may have complained to the FCC since it sounds like the digital VHF propagation is a known issue.

So my question is simply why is there a 30kw limit? Also, are there any efforts to raise this?
Likely because the VHF-Hi band is so crowded in the Northeast. I doubt they will be raised.

The current power levels are substantially higher than they originally were went VHF first went digital. (the VHF Nightmare era ) If I remember correctly the power levels were somewhere around 10kw for 7, 9, 11 & 13.
The United States is split into three "zones" for television licensing purposes. Zone I ( https://www.rabbitears.info/Zone1.jpg ) is the northeast and Great Lakes region, where population density is high and cities are close together. Zone III is the area surrounding the Gulf of Mexico, while Zone II is "everywhere else". In Zone I, the power limits are lower than in Zone II because, as suggested, it is a crowded part of the country. WUSA and WJLA actually operate in excess of the 30 kW limit, having signed agreements with other impacted stations and received waivers to operate at 52 kW.

As for attempts to raise it, the FCC proposed to do so in 2010 or so. It didn't go anywhere.

WETA has pushed 26.2 up to HD.
Running promos to that effect.
Yes, and I also note they dropped 26-1 back to 720p once again. Looks like it was that way at least as far back as May and I just didn't notice at the time.

- Trip
 

·
Registered
Joined
·
16 Posts
Thanks and that is interesting about the DC VHF stations. Since they are my primary CBS and NBC stations, I rather have them running at higher power.

On another note, appears that WMAR is currently having issues. I lost their signal earlier this morning, and checked a few nearby signal graphs (leesburg and alexandria) and they appear to lost WMAR as well.
 

·
Registered
Joined
·
12 Posts
Thanks and that is interesting about the DC VHF stations. Since they are my primary CBS and NBC stations, I rather have them running at higher power.

On another note, appears that WMAR is currently having issues. I lost their signal earlier this morning, and checked a few nearby signal graphs (leesburg and alexandria) and they appear to lost WMAR as well.
2 is where it was at on the 75 kW backup facility - barely above background noise here. 11 where it was on the side mount antenna. No real change in 13. Interestingly 2 filed its L2C today which is the last one left.

ETA: back already (1029)
 

·
Registered
Joined
·
16 Posts
looks like they are back up now.

n8hoo, it looks like you are just on the reception fringe for WBAL and WJZ. Do you think a different antenna location would put you over the threshold?

Being that close to getting reliable reception would drive me crazy.
 

·
Registered
Joined
·
12 Posts
looks like they are back up now.

n8hoo, it looks like you are just on the reception fringe for WBAL and WJZ. Do you think a different antenna location would put you over the threshold?

Being that close to getting reliable reception would drive me crazy.
It kind of does. It's a rental so it's in the attic - probably even being outside with the same antenna would do the trick. It's already pointed toward TV Hill as close as I can before the neighboring townhouse gets in the way, and it's jammed as close to the roof as possible. The antenna is a winegard 7694 and the transformer box is on the fritz, so I'd be open to suggestions when it comes to similarly-sized replacements...

However, the Baltimore channel that is most useful for me is WBFF for its early Jeopardy airing and NFL games so those two would really be gravy.
 

·
Registered
Joined
·
56 Posts
The atmosphere has been so unstable in the past few weeks, and looks like it will continue to be so for a while, I wouldn't write off receiving the Baltimore stations once the weather settles and NFL season begins. I've often been losing the DC stations and sometimes WJZ and WBAL in the morning. But that's the way it goes OTA sometimes.

WUSA messed up 68-1's virtual station id when they updated Justice to Crime on Aug 1. Says UNKNOWN now.
 

·
Registered
Joined
·
16 Posts
If you are OK with the winegard UHF reception, then I would suggest a dedicated VHF antenna. The Stellar Labs deep fringe VHF Hi (through Newark) is what I have. It is well worth the $35, a very solid build (all metal). It would be about 20" longer than your current setup, and guessing about the same width. You would also need a VHF/UHF combiner, which you can get on Newark for $10. They charge shipping, but is is reasonable and deliver within a two days or so. I say this because some resellers have the same antenna on Amazon for more inflated price.

If it doesn't get you better reception, then you are only out $50. But since you are right on the threshold, I would say it is worth the gamble.
 

·
Registered
Joined
·
12 Posts
The Stellar Labs deep fringe VHF Hi (through Newark) is what I have.
Interesting, I wondered if it was worth a shot. I have their directional FM antenna up there and it can pull most of the 250-watt translators out of DC. (I don't have much need for it anymore since upgrading to an HD radio, though, so this could take its place.)
 

·
Registered
Joined
·
1,925 Posts
Interesting, I wondered if it was worth a shot. I have their directional FM antenna up there and it can pull most of the 250-watt translators out of DC. (I don't have much need for it anymore since upgrading to an HD radio, though, so this could take its place.)
I have an extra Stellar Labs Deep Fringe VHF-Hi antenna. Do you want to trade it for your FM antenna.
 

·
Registered
Joined
·
1,925 Posts
What's the difference between actual power output & Effective Radiated Power? A promo on Charlottesville's WWWV says they have 50,000 watts, but everywhere I look only shows 8,900 watts. Not sure if I am missing something?
 

·
Registered
Joined
·
17,298 Posts
What's the difference between actual power output & Effective Radiated Power? A promo on Charlottesville's WWWV says they have 50,000 watts, but everywhere I look only shows 8,900 watts. Not sure if I am missing something?
WWWV has been lying about their power level for a very long time. I called to complain about it when I was at UVA and got a very dismissive answer.

Essentially what they mean is that they're the equivalent of a Class B 50 kW station at max height of 150 meters. Because they're on Carters Mountain, much higher up than 150 meters, they have to reduce power to keep the same coverage they would have if they were 150 meters at 50 kW, which turns out to be 8.9 kW.

It's extremely misleading to the public but nobody there cares.

- Trip
 

·
Registered
Joined
·
1,925 Posts
Thanks for the explanation Trip. Their signal is pretty darn good here given the distance & their sound quality is about the best i have heard on FM. They must have some pretty good audio equipment.
 

·
Registered
Joined
·
220 Posts
During the NewsHour, WETA had a hard time tonight. I assume it's lightning related as T-storms were passing through, but it was interesting.

They dropped carrier a few times [understandable], but at other times the program content vanished, but with the WETA bug in the lower right corner still visible on their channels. I've not seen that before.
 

·
Registered
Joined
·
220 Posts
[WETA]
Yes, and I also note they dropped 26-1 back to 720p once again. Looks like it was that way at least as far back as May and I just didn't notice at the time.

- Trip
I'm not clear on what the BW limits are on one carrier. Is there a calculator for how many channels of each resolution are possible?
 

·
Registered
Joined
·
17,298 Posts
No. You could have 99 1080i streams on a channel, though none of them would be watchable. There's just the trade-off between quantity and quality.

- Trip
 
  • Like
Reactions: TheKrell

·
Registered
Joined
·
35 Posts
Has anyone heard any rumblings about lighting up ATSC 3.0 in our market? I know Sinclair is buying WDCO-CD and WIAV-CD, I assume they'll convert one or both to 3.0?
 

·
Registered
Joined
·
12 Posts
Very, very strong tropo to the northeast happening overnight and this morning. At my location the only usable stations between DC and Balt are 2 and 9, with everyone else wiped out or nearly so. I had locks on two NYC-market stations and WPVI overnight. Never seen it like this before!
 
15461 - 15480 of 15503 Posts
Top