San Francisco, CA - OTA - Page 285

According to the FCC files, the K46LG site WSW of Morgan Hill has a tower height of 1,466 feet (446.9 meters) above ground. That makes it 3,064 feet above average terrain and 4,029 feet above sea level.

The KXTV channel 10 tower at Walnut Grove is 545 feet taller. It's 2,011 feet tall but the base is at sea level. I think it's the tallest tower in the state. The KOVR 13 (RF25) tower is almost as tall at 1,949 feet.

For comparison purposes, Sutro Tower is 951 feet tall, but it's sitting at a height of 834 feet on Mt. Sutro putting KGO's antenna at 1,785 feet above sea level.

Edit: I just noticed Calavera's post. I don't know where he got his figures, but according to him the K46LG tower is 62 feet higher that what I noted above.

Larry
SF

FCC TV Query here:

http://transition.fcc.gov/fcc-bin/tv...&slon2=&size=9

The antenna is 466.9 meter above the ground or 1531'. Of course that doesn't say where the antenna is on the tower. On the side? On the top?

Okay. Here is the tower registration data:

http://wireless2.fcc.gov/UlsApp/AsrS...?regKey=120762

So if I'm reading this right the total height is 473.1 meters so it looks like the K46LG antenna is not quite at the top.

Chuck

Larry, KXTV and KOVR co-own the same tower. We lease space to KTFK, Channel 64.

Bob

The KXTV/KOVR joint venture tower near Walnut Grove is actually 624.5 meters or 2048.8 feet tall measured to the highest point per the tower registration information. The FCC cares about the height of the center of radiation for coverage calculations not the total height of the structure.

Thanks Bob and Rory for the clarifications.

Is the KXTV/KOVR tower the tallest in California? How's it compare to others across the country?

Larry

K46LG transmitter is located at Mt. Madonna.

Per this site the Join Venture tower is the sixth tallest in the world.

http://en.wikipedia.org/wiki/List_of..._United_States

This was not by design. The tower was built as 2000 feet tall but when new DTV antennas needed to be added at the beginning of the conversion to DTV the choice was made to lift the existing analog KOVR and KXTV antennas off and install new DTV antennas where they had been. The analog antennas were then reinstalled on top of the new DTV antennas. This was done using a sky crane helicopter. There was at the time a significant problem getting approval for the increased height from the FAA and an attorney had to be hired to get the increased height approved.

So does anyone know how this Sacramento tower is built for earthquake rating?
From the freeway, it looks top heavy. Sutro is supposed to have a concrete base over rated for the tower structure it supports.
Walnut Grove is less than 50 miles from the Hayward fault.
1989 Loma Prieta earthquake was felt in Sacramento. (Far away from Santa Cruz)
Some day ..... ..... Hopefully not in my lifetime.
Well, the fault is a 10 minute walk from here. I'm doomed.

Hi,

You are right, Santa Clara County Park "Mt. Madonna" has not been mentioned in public, I did say that in a PM to Larry today.

I measured with my Topo program that K46LG CP transmitter is located 5.07 miles to the North West of Mt. Madonna. Park boundary is not shown but I do not think it extends that far North. That is half the distance to Loma Prieta.

1893' vs. 2500' says to me that it being on Mt. Madonna is incorrect. But you did say "at".

It is 5.3 miles from Hecker Pass on CA 152 if I got the location of the road sign correct.

I said to Larry that it was visible from a dirt road in Mt. Madonna County park.

It popped up while I was riding a motorcycle somewhere nearby, but most roads are dead ends in that area except for Redwood Retreat Rd which connects with Mount Madonna Rd which crosses over Summit Road and down to Santa Cruz County.

The "old" KSBW tower is very hard to spot as it is so very remote and most roads are in canyons with no views of the Summit Road sky line.

Some one living in South Santa Clara County may be able to find a Google Earth Street View that shows it. Thanks Calaveras.

The best way to locate it is to go to:

The FCC page http://transition.fcc.gov/fcc-bin/co...&state=CA&.kml

Find the Construction Permit and click on the Google Earth "KML file (51 dBu)" link and zoom in until you see the transmitter building and tower.

Then zoom out until you see where the tower is located. It is very remote!

You of course need to have Google Earth installed, but that is so much fun to use!

Summit Road is paved quite a way North, I could not locate the locked gate due to tree cover but I suspect it is where Summit Road turns to dirt. Amazing that I was able to find that point with Google Earth.

SHF

 

K46LG-d.zip 5.3095703125k . file

The Walnut Grove towers are guyed towers and don't require the kind of base that the free standing Sutro tower does.

Chuck

from what I remember the KSBW could not get permission to build the antenna on Mt. Madonna
possibly due to it being public lands. so they got permission to build the antenna on some private land
right adjacent to it.

it is funny you mention quakes. as a amateur geologist ( i like to think of myself as one)
from my studies we are well over due!
what I mean, the last big quake the SAF (san andreas fault) moved 13 feet.
that was 1906. it did not move during the loma prieta quake...a pre shock in my opinion.
the SAF stores up movement at 2.2" a year. do the math, it is over 19 feet of movement is stored up.
it will be big! I was about 5 miles from the loma quake by the way a bird flies near LG.

now worse news about the SAF. the area at the grapevine (I-5) south of bakersfield the Fort Tejon section of it.
1857 was the last big one; 23 feet movement. today it has 28 feet on movement stored up.

now even worse news about the SAF the government does not want you to know as it might
cause movement out of Ca. and lower property prices...
the area south of Palmsprings Ca. last time it moved was well over 500 years ago and last movement was 50 feet.
so that means it has well over 92 feet of movement stored up. now as for south of the Salton Sea area is under water so it can not be checked!?!?

now the real big disturbing thing to me. if you add all that movement and any one triggered the other.
with three sections+, well as one geologist reported, "it will be a duzzie."
by my estimates about 10.5 or bigger as the whole coast will move.
not much in Ca. will not feel it as a guess of 30+ minutes of shaking.
any house near the SAF will fall apart or fall over, but I feel most people will survive.

After a lot of looking in Google Earth I finally found a place where you can see the old KSBW tower in Street Level View. Image is attached.

Or in Google Earth go here:

37 00 17.7 N, 121 47 41.5 W

Zoom up to maximum on Browns Valley Rd. Switch to Street View. You may have to go up or down the road one frame.

Google Earth has no street level view from Summit Level Road which is where you'd really be able to see the tower.

Chuck

If you go the K46LG construction permit entry on the FCC site linked from my DTV lists - http://transition.fcc.gov/fcc-bin/tvq?call=K46LG - and click on the Contour Map link, you can zoom in and get a great view of the tower from the Google map satellite view. You don't need Google Earth to do this.

Larry
SF

Those Crazy Kids at KAXT Channel 1 are at it again

1.1 is now half Weather Nation Half EPG zip2it

1.12 Wave goodbye to the Corner Store and say Hello to the CoolTV via KQSL 8.1

What changes will be coming to KAXT for the mouth of may???

wow, the things you can learn from thinking out loud!

i'd always figured the the sacramento area's broadcast antennas were up in the last of the hills that drop down to the valley like woodland or that area.

somewhere on the internet, youtube im pretty sure, theres a video of that ole boys operations out of his studio, man talk about a 'duct tape and tie-wire' operation!

I had this tower built, together with my counterpart at KXTV, in 1986. It was built to local earthquake and, more importantly, windload standards at the time and continues to be inspected and upgraded to meet new standards.

When the Loma Prieta earthquake occurred, we had reports of antennas swinging wildly. I suspect these were quite exaggerated. Nevertheless, we had the tower inspected immediately and there was no damage.

As an aside, although I am the Director of Engineering/Operations/IT, I am a geologist by education.

- Bob

Now 1.1 is all weather, no guide data at all. This is a travesty! I use the guide all the time because it is so much more reliable than the psip carp.

Whoever made the decision to go all-weather ought to be shot! In a vital area!

Am I the only one having problems with OTA KGO tv 7.1 this past week?

I'm in Menlo Park 94025 just off Sand Hill. My rooftop CM4228 hooked up to my two Sony flatscreen TVs has worked just fine for over 2 yrs until this past week. My setup hasn't changed. i tried re-scanning, but the TVs won't even p/u 7.1. Manually entering 7.1 just shows I have no signal coming into the tvs for this channel. Interestingly, my old tv with set-top rabbit ears in the guest room displays KGO just fine despite a signal strength of 37. The sony tvs don't display a signal strength. I have not yet attached the rabbit ears to either of my flat screens tvs. I know KGO has beeen flaky at times in the past, but not for an entire week. And again, Nothing has changed with my setup, and all other channels come in just fine. Any advice much appreciated.

I just returned from visiting a friend and we looked at KGO on his Sony TV and on my spectrum analyzer. It was coming in fine and he's 113 miles from Sutro.

Sony TVs do display the signal strength and a whole lot more. On models up to few years old the Diagnostic Screen is located under the Customer Service menu.

It's really hard to troubleshoot these sorts of problems in a forum. Despite your past (flaky?) success I'd use a VHF antenna to receive VHF, not a UHF antenna.

Chuck

No problems here with that station. Please note that the CM4228 by design, is a UHF tv antenna.
OTA tv reception is UHF-VHF, And KGO is on VHF-7
Simply replace that antenna with a UHF-VHF antenna, or simply add a VHF antenna for satisfactory reception of vhf stations.

Thanks Chuck and 888. I did finally find the signal strength indicator in the Sony menu under product support.

I know the CM4228 is supposed to be UHF-only, but it worked fine for the past 2 years as a UHF antenna that also gave me VHF KGO as well. If I suddenly need a VHF antenna, then fine. But why didn't I need one over the past 2 yrs?

I wonder if our recent heavy rains or critters under the house might be responsible, though I'd expect more of an "or nothing problem". I'll check the Balun, all the wires and connections, maybe make sure the CM4228s 2 grids are in good contact with each other. If nothing works, I'm off to Frys for a VHF antenna to add on...
Thanks again.

KGO is reception is fine here in San Ramon, CA. I use RCA ANT751 antenna for VHF channels though it could be used for both VHF/UHF channels. CM4228 is UHF antenna but it could pull VHF channels if they are strong enough. Most likely there could be problem with the antenna connection some where.

Right now, The trees here are starting to bloom & leaf up. And they grow every year. Signals can be changed by this.
We also had some heavy winds in the Bay Area, that may also "move" antennas out of alignment.
Not saying this is the problem, but all factors must be looked at.

If you're using the CM4228 for VHF band, signals will be substantially lower.
It will work ......only until that hawk flies in front of it and blocks the signal.

Today Weather Nation is at the top of the screen and the guide data is back on the lower half. I notice that they've added the Monterey/Salinas and the Sacramento stations to the guide.

Larry
SF

Well it is all fixed now. I think it was a splitter issue. My CM4228 is back to giving me vhf KGO 7.1 with a tv signal strength of 83 (whatever that means). I went up on the roof and inspected all connections, undid and redid my balun connections, coax connections, etc. Didn't make a difference. Antenna was rock-solid in its clamp, and hadn't moved or rotated. Then I noticed signal strength was fluctuating every ~1/2 sec. Hmmm. I looked at my 2-way splitter from antenna to both tvs (no pre-amp), undid all 3 connections and redid them and all was back to normal. Fluctuating signal strength resolved. I think reception might also be better on the other channels too. No new vhf antenna needed--Saved me a trip to Fry's and a crawl under the house. Thanks again for everyone's help!

I know it seems impossible, but sometimes the center conductor on a piece of cable will develop resistance to the center receptacle in the connector or not make contact at all. Since your VHF signals are weak compared to your UHF signals, a little resistance could drop out channel 7 where the 4228 performs the poorest but still be good enough to work on the other channels.

If there's a little oxidation on the center connector sanding with some very fine sandpaper can clean that up.

Chuck

Hi,

KNTV at 10 PM showed several lighting strikes on cranes at the port of Oakland.

The path of the cell appeared to go right over San Bruno.

At ~ 10:50 PM I discovered KNTV was off the air.

SHF
---------------
Found on Facebook:



NBC Bay Area

about an hour ago.


NBC Bay Area's transmitter has been disabled by the weather, so if you're watching with an antenna, you may not see us. Cable and Direct should be unaffected.

Weird i was watching 30 rock on kntv via dish and about 2/3 of the way through the show kntv went totally green screen. checked back to see if it was up when fallon was supposed to start, and still green screen.

weird how you were able to watch at 10:00 when i lost reception before 9:00.

My dvr did not record the office at 9. So that leads me to believe it was off the air at that time.