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Discussion Starter · #1 ·
OK, so who out there is receiving a workable HD OTA signal in the East San Francisco Bay Area? In particular, I am asking about in the valley from Alamo through Dublin.


For those of us still doubtful that we will be able to receive anything, it would be fantastic to get some specifics from those of you who have been successful, such as:


City you live in

Channels you can get from Sutro Tower (SF)

Channels you can get from Sacramento

Antenna/pre-amp combination you use

Antenna location (above roofline - how much, or in attic)



Survey says...



[This message has been edited by Tom Lewis (edited 05-04-2001).]
 

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Discussion Starter · #2 ·
Stuart,


Sounds like you are in a fairly good position to see Sac, but are in the same shadow when facing SF that I am in. Unfortunately, I am also shadowed by Mt. Diablo when facing Sac.


I am seriously thinking about waiting for the new Zenith STB and putting up a long UHF yagi (and bracing for complaints from the neighbors), and then hoping I can get something OTA. While I too have changed from AT&T cable to DirecTV, I can't say I am satisfied with the lack of artifacts..


Stuart, thanks for the valuable input!!


Cheers


PS: Anyone else with key learnings for the East SF Bay Area?
 

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Tom,


I've (unfortunately) got lots of experience with this from the school of hard knocks.


I'm Located in Dublin, close to the west hills, with lots of dynamic multipath.


I'm using two different antennas to get better coverage.


CM4228 8 bay bow tie up 30 feet, CM7777 preamp, picks up Sac HD (analog equivalents) 10, 40; SF HD 7,20,44 (sometimes 2 and 4, based on multipath)


CM4248 yagi up 50 feet, 30 feet south of 4228: picks up Sac HD 10, 13, 40; SF HD 5, 9.


You can see from the above what a big difference height, exact location, and antenna type makes - channels not receivable on one antenna can be received on the other.


So my best recommendation is that you'll have to experiment a lot. You may get lucky the first time, you may not - keep trying different heights, locations, and antennas. Overall the CM 4228 at about 30 feet picks up more than the 4248 at 50 feet.


Also, the Samsung SIRT150 is the best tuner I've found so far under these conditions of weak signals and multipath. Tuners should get better over time.


Les
 

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Discussion Starter · #4 ·
Les,


If I recall correctly, you responded to a topic I started several months ago on the same topic. Looks like you have really got this down to a science (or maybe it is a bit of art too.) Congratulations!!


So the rumors about the good performance of the 4228 do apply to our area. Is it correct to assume that you still are using a 4248 for the additional stations because of the antenna location and height, and not because you feel the 4248 is better for these additional stations? Asked another way, if you were to start again, would you go out and buy two of the 4228s or would you buy one of each type?


Any thoughts from you guys about the Blake antenna ( http://www.blake-aerials.co.uk/ ) discussed in: http://www.avsforum.com/ubb/Forum11/HTML/013407-2.html


Tom
 

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Tom,


I'm still in the process of experimenting will different set-ups because I'm not happy completely with anything so far. That's probably a function of the inadequacy of the currently available tuners for multipath situations and the low power/low antenna height of the transmitters. In the meantime, everything is still evolving.


The problem is, I don't know how much my own particular situation can be transferred to other locations. The hills to the west between us and the Sutro tower create a wide variety of different multipath conditions. Even at my own location, moving the antenna up or down 5 feet and sideways ten feet makes a big difference in which stations can be received and how well.


Nevertheless, based on my tests so far, if I could only have one antenna, it would be the 4228 at about 30 feet, because that consistently does better on more stations. It makes sense, too, since that antenna has the best front to back ratio and narrowest beamwidth - in short, it can reject multipath better than other antennas.


I do plan to replace the 4248 with another 4228 so I can see that it does at greater height and a different location. My suspicion is that will be the best performing antenna - but I'll probably report when that happens.


No experience with the Blake antennas - yet.


Les
 

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Discussion Starter · #6 ·
Les,


Sounds like the 4228 is good.


Questions about rotation: Do you use a rotor for either of these installations? Do you need to fine-tune the direction with the rotor to get different channels from the same city? If this need more pronounced with either of the antennas? The reason I am asking is that I expect that the more narrow the beamwidth, the more adjustment will be necessary.


Where can I get beamwidth and f/b ratio results for these antennas? Is there some site that has listed this data in one spot? Results that have been obtained by a non-partial third party are most valuable because them measuring techniques, they do vary...
 

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Quote:
Originally posted by Tom Lewis:
Where can I get beamwidth and f/b ratio results for these antennas? Is there some site that has listed this data in one spot?
Tom, Sometime this weekend I will fix this info in a HTML format and e-mail to you (I have in WordPerfect 8 format).




------------------

Wendell

Technical Services Supervisor

MAETV
 

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Discussion Starter · #8 ·
Wendell,


Wow, that's fantastic.


I use Word 2000 and can read WordPerfect 6.x (*.wpd and *.doc extensions). Perhaps you can save time and just send in a lower rev of WP??


Regardless, thanks.
 

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Tom,


A rotator is essential for multipath conditions. Each station may have slightly different azimuth for best reception. The 4228 is the most sensitive to proper positioning, consistent with its specifications. But when it's locked (may be only 2 or 3 degrees makes a difference) it does the best job.


Les
 

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I'm in Livermore, so I have a little better situation in regards to Sutro than you do in Dublin. I can get all of the stations from Sutro with the CM4251 and CM7775 preamp, but I do sometimes get breakups due to multipath. I have a CM4248 ready to go up on the roof this weekend to see if that improves things any...if not...I'm going to try the CM4228 next. The CM4251 does a great job with CBS and ABC from Sacramento....I actually get these stations better than the ones from Sutro, even though Sutro is 37 miles away and Sac is about 70.


The STB can make a huge difference in how it responds to multipath. My hipix card does NOT handle multipath well at all. I currently have a Zenith beta unit that really works well with multipath....so that new Zenith box coming out this summer/fall might be a good bet for those of us in high multipath areas.


Tom...contact me privately and maybe we can work out a test of an STB at your house.


Chris
 

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R8der,


The Sacramento stations broadcast their signals from Walnut Grove, which is southwest of Sacramento. You are more like 40 miles from the Sacramento transmit site, which is why you get them so well.


Do you get KCRA, analog 3 (digital 35)? I can't get them no matter what - but it appears their antenna is lower than the others.


Les
 

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Discussion Starter · #12 ·
Dave,


I ended up installing a CM 4248 with CM wireless remote controlled rotor on a mast ~ 10 ft above roof line. I also got a Blake JBX-21WB and tried it with no improvement.


I was able to get several stations from Sacramento and San Francisco using a STB I borrowed. I am waiting until the Zenith box comes out (maybe 4 weeks) and intend to buy that one, provided it works well.


Bottomline is that I was delighted and surprised with what I could get from San Ramon. I was sure the hills would make it impossible to get anything from Sutro Tower (SF), which was not the case.


If you want to see my installation (sans STB), please sent me an email.


BTW, there is a stipulation in my home owners assn by laws that we are required to notify them in the case of installing an exterior antenna. However, the rule stipulating that antennas cannot be erected was removed. So, before the installation, I wrote a nice letter to them informing then that I was going to install an antenna for TV reception. I cited the FCC site and said that my installation would be in accordance with the FCC guidelines. I did not hear one peep from them either before, or after the antenna was installed.


Check out and subscribe to the following group: http://groups.yahoo.com/group/HDTV-in-SFbay


You can email Chris (r8der) or me by clucking the 'Mail' icon to the right on the top of our posts.
 

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Thanks god for search engines http://www.avsforum.com/ubb/smile.gif


I too live in Livermore and have been researching Antennas for DTV. Hopefully r8der still reads the forums and will let us know if the different antennas he tried worked out. Maybe there is someone else on these boards that live near me that can comment as well? I am reluctant to try it out based on what I've read so far. Sounds like I can get some stations though. My biggest problem is my Home-owners association. They state that they do not allow Antennas on the roof. Little do they know they must comply with FCC laws http://www.avsforum.com/ubb/biggrin.gif Before I fight that fight though, I want to make sure it is worth it http://www.avsforum.com/ubb/smile.gif Any input is appreciated.


Thanks,


Dave
 

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Yes, I still read these forums...;-)


I did indeed put that CM4248 up and it worked out better than the huge CM4251 (that is currently laying on my roof for lack of anything better to do with it). The CM4248 is a much better solution anyways, since its much lighter and much less susceptible to wind problems. It's also a hell of a lot cheaper (about $50 shipped off the internet).


You will also need the CM7775 preamp to help boost the signal.


If you order the antenna and preamp, you can borrow that same Zenith STB for a day or two to check on your reception capabilities. You can just hook it up to a computer monitor to see what you end up getting. Drop me a private e-mail and let me know.


Tom....I'm surprised you've not sprung for the Dish 6000 at this point..;-) I read in another thread that the Zenith STB has been delayed until November because they are waiting on DirecTV approval to release it. :-(


Chris
 

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Discussion Starter · #15 ·
Chris,


Yes, I am surprised too. I predict that only the Zenith will do the trick for me because of its OTA capabilities, so I am willing to wait a bit longer.


I don't think anyone can predict when a particular DirecTV STB will be released based on the history of these announcements. Fact is that getting approval from DirecTV is a factor that is out of the control of the STB vendor (to a degree). So, they can estimate when DirecTV will approve the release, but I suspect it is more like "it's not done until its done" type of situation.


Maybe I am talking myself into not waiting any longer...
 

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Hi guys,


Thanks for all of the good info. btw, I registered at the yahoo hd site. Sounds like I can get most of the stations from where I live but the one thing I am confused about is the Zenith box is continually mentioned as though it is the only box that will work properly. Am I missing something? I have the Toshiba DST-3000 and from what I've read, hooking an Antenna to it should be fine. I see that it is mentioned as handling multi-path issues better.


Thanks,


Dave
 

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Discussion Starter · #17 ·
Quote:
Originally posted by Helevitia:
Hi guys,


...the Zenith box is continually mentioned as though it is the only box that will work properly.

Thanks,


Dave
Dave,


It's my objective to get as many stations from both Sutro Tower and Sac as possible, and multipath rejection is a consideration for me because of hills between me and both of the broadcasting locations. There are claims that the "3rd gen" OTA receiver in the Zenith will be the best at multipath rejection. So, that is why I am interested in that one.


On the other hand, the Zenith is not available now. It is easy to wait for the next best thing, and end up waiting forever. The Tosh has a good reputation, and perhaps I will get it if I cannot stand waiting any longer. For me it is a trade off delaying the purchase with the result being perhaps one additional station coming in vs. getting a STB now and enjoying it ASAP.
 
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