reception help in antioch ca

[deltatv]

hi all,
i have an antenna mounted up on the hill in my backyard. its a radio shack model about 8 feet long. its mounted on 2 pieces of conduit where one slides into the other so I can turn it. it is about 32 feet above the grade my house sits on.I have a 100 foot rg6 cable running down the hill to my panasonic g10 plasma tv. here is a link to my report http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d3cf4afeda96e26 i can aim it to sacramento and get all the green channels in the report but when I aim it to san francisco I have a problem with channel 7-1. It works fine from around 9 to 5 say like 37% according to my tv and then at a certain time its 0% steady till the next day. whats happening? when i point to the city or246 degrees i sometimes get 4.1 but it cuts out so much it almost unusable except in the mornings its ok. other english speaking channels i get facing 246 are 2.1, 4.1 sometimes,5.1,7-1,7-2,7-3,9-1,9-2,9-3,11-1,11-2,11-3,although the elevens are iffy like channel sevens,20-1,22-1,22-2,22-3,44,65-1,65-2,65-3.
so what antenna and preamp should i use to get more stations and whats with channel 7 and if i get another antenna can i use them both with one towards sacramento and the other to san francisco?

[John Candle]

Read and understand this about Real Digital Tv Channels and Virtual Digital Tv Channels. http://firum,tvfool.com/showthread.php?t=695 . . Starting with KTLN-DT 47 IND. and on down are adjacent channel television transmitter warnings and co-channel television transmitter warnings. The main channel , the one you will like to watch is weak/not strong and the adjacent channel and co-channel are interfering.

[GroundUrMast]

Click on KGO on your report, for example, and you will see that the signal is blocked by terrain. And as John has pointed out, KRNV is also transmitting on channel 7, the difference in signal levels is less than 20 dB... The deck is stacked against you getting reliable reception from the SF stations.

How much are you willing to spend with no guaranty of reliable reception of the SF stations? Some folks are willing to spend a lot on their hobbies, so I don't want to assume I know what you're desire is.

[deltatv]

thanks you guys. I get it now, channel 7-1 is broadcasting on real vhf channel 7 which is already bad for reception, plus its broadcasting at lower power relative to the other sf stations I receive, resulting in lower eff power. the cochannel interference is coming from almost directly behind the antenna. sometimes I get channel 7 kgo at 38%. So if I spent the money on a Winegard HD8200U and replaced my 8 foot radio shack antenna there still might be not enough signal right? maybe kgo will change the real channel it broadcasts on someday. I also painted my antenna a brown color when I installed it so the neighbors would complain less. that doesnt hurt anything does it?

[GroundUrMast]

I doubt the layer of paint is a major factor here.

You are tracking with our thinking pretty much.

If I was given a Y10713, I would like to see how it does aimed at SF. If I was given two Y10713's I would even play with a horizontal stacking arrangement. http://forum.tvfool.com/showthread.php?t=1024

But I'm not sure I would spend my own money...

[John Candle]

Nice of you to paint the Tv antenna. With the way I see the world lately , I doubt that the neighbors even know what they are doing. And even so it's a Federal Law that YES You Can install and use Tv antennas and other antennas. http://www.fcc.gov/mb/facts/otard.html . This is a All Encompassing Federal Law because their are many nut case antenna haters loose in the USA that see it as their mission that no one can have a Tv antenna or any other type or kind of antenna.

[Dave Loudin]

Actually, VHF channels like 7 bend over obstructions better than UHF channels do. Note that despite the lower transmitter power, it is predicted to be your strongest SF station. Click on any station in the table of your report to pop up the terrain profile af the path from transmitter (far left) to you (far right).