Re: [HDTV-in-SFbay] Re: Signal Reports
- Nothing is published, but Larry's summary below appears to be accurate.There is always the possibility of supplier and construction delays, which is why nobody publishes anything.The only hard date is the federally mandated one...On Dec 4, 2008, at 2:13 PM, Larry Kenney wrote:On Dec 4, 2008, at 12:03 PM, epicurusradium wrote:Here's the overall plan and schedule for Bay Area stations.There will be a minor change made at KNTV. KNTV plans to move their digital antenna to the top of the tower, replacing the analog antenna, and make some minor adjustments. This will raise the digital antenna about 50 feet. I haven't seen any date for when this is going to happen. I'm sure Richard will keep us posted on the changes there.There will be some major changes at KICU. They will be using an auxiliary antenna at 95% power when they move to channel 36 in February. They will be installing a new transmitter and a new antenna and plan to have them ready go with full power of 550 kW by 8-18-09. They have applied for 1000 kW on channel 36, but have not received an OK yet from the FCC. They're now transmitting with 251 kW on channel 52.KTNC on Mt. Diablo will change from 47.3 kW on channel 63 to 40 kW on channel 14 in February using the same antenna height.KFTY on Mt. St. Helena will change from 30 kW on channel 54 to 20 kW on channel 32 using the same antenna height.Sutro Tower stations are ones where you'll see the most changes. You can take a look at the present and future antenna arrangements in the drawings at http://www.larrykenney.com/sutrotwr.html - compliments of Sutro Tower, Inc.In February, KGO will move from channel 24 to 7, KRON will move from channel 57 to 38 and KTVU will move from channel 56 to 44. KGO will use its present analog antenna, KRON and KTVU will continue to use the temporary antennas they're using now. KRON will go to 50% power on channel 57 sometime this month and come up on channel 38 at 50% power in February. They'll go to full power by the end of May. All of the other stations will remain on the same channel and the temporary antenna that they're using now. The temporary antennas are between 1371 and 1433 feet above average terrain.After the analog stations go off the air, all of the analog antennas will be removed from Sutro Tower and new antennas will be installed in their place high atop the tower. KGO will get a new antenna too. While construction work is going on during the day, all stations will transmit from auxiliary antennas, scheduled to be installed this month at the 1200 to 1225 foot level, then return to their present antennas at night and on weekends. (I plan to post photos of the antenna installation work on my Sutro Tower page as work progresses.)When the new antennas are ready and all stations switch over to them is when you're going to see the biggest change. The new antennas will be 220 to 275 feet higher than the present temporary antennas at heights between 1601 and 1680 feet above average terrain and above the tower rather than within the framework. The earliest date I've seen for use of the new antennas is late August, 2009. All work is scheduled to be completed by the end of October.So that's the planned schedule of events. By the end of October next year every station should be at it's finally power allocation and on its permanent antenna. Only then will you know for sure what our reception will be.LarrySF
The broadcast antennas are physically vertical looking but they transmit in the horizontal plane. All television stations are licensed to operate at their power in the horizontal plane if there is a vertical element that doesn’t count in operational power. KNTV will replace the old top mount ch-11 antenna with a new ch-12 top mount antenna sometime in 2009 I believe (we will then have a main and standby antenna capable of 100% power operation) and when completed we will have the ability to have a 100% power in the vertical plane as well as the horizontal plane. It is planned to operate that way as there are many indoor antenna users in the bay area (especially in SF) and to this point no one builds a good indoor VHF antenna. By the way we currently operate at 25% vertical.
From: HDTV-in-SFbay@yahoogroups.com [mailto: HDTV-in-SFbay@yahoogroups.com ] On Behalf Of Frank Nemec W6NJR
Sent: Friday, December 12, 2008 8:34 AM
Subject: [HDTV-in-SFbay] Re: Sugnal Report
The screen is indeed aluminum. The product catalog says so, and nearly
all residential TV antennas use aluminum elements for high conductivity
and low cost and weight. But they're not so good for strength, so I
would always lose about 3 long elements per season to the wind.
Sometimes they anodize the aluminum, I think mainly because the gold
finish looked better and sold better.
The new model, the 4228HD, has close-spaced horizontal elements running
the full width of the antenna. That makes it an almost perfect
reflector for the horizontally- polarized component of the signal, nearly
as good as a solid aluminum panel would be. The horizontal gap is
mostly just a slightly wider gap than all the others. The 'driven'
elements (the ones connected to the feedline) are also most sensitive to
the horizontally- polarized component of the signal. That's why the
horizontal gap wouldn't make much difference.
That led me to wonder. Since all the TV antennas on Sutro are vertical,
why don't we install these antennas vertically? I suspect the reason is
that the vertical stacking makes the sensitivity pattern flat, like a
horizontal pancake. You sacrifice the polarization match because for an
antenna pointed north, extra sensitivity to the northeast and northwest
is more useful than sensitivity toward the dirt and toward the north star.
PS: Sorry for the confusion I caused regarding Nick Sayer's antenna
setup. I was reading the compass bearing from him to the various
stations, but I was mistakenly reading that from the distance column
instead of the heading column.