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I lived in Richmond/San Pablo area and I want your expertise on what's the best antenna setup for my location base of tvfool report that follows: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=f1f0096f79d7c6 thanks in advance
You have lots of strong signals, so an average VHF/UHF antenna should work fine for you. Something like the Winegard HD7694 - http://www.solidsignal.com/pview.asp?p=HD7694P&ss=526979 - should get signals from all the stations, but your problem is that the signals come from several different directions. You can see that on the TV Fool diagram. You have 11 stations coming from Sutro Tower in San Francisco, 4 stations from Mt. San Bruno, just south of San Francisco, 6 stations coming from the hills above Fremont, two from Mt. Diablo, several from Walnut Grove and several from Marin and Sonoma Counties. You can either concentrate on getting the ones from Sutro and Mt. San Bruno and get the others hit or miss, or you can get a rotor so that you can turn the antenna in any direction you need.

I strongly recommend that you mount the antenna outside on the roof, not in the attic. Roofing materials can decrease your signal strength up to 50%.

Larry
 

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I lived in Richmond/San Pablo area and I want your expertise on what's the best antenna setup for my location base of tvfool report that follows: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3df1f0096f79d7c6 thanks in advance

Which stations are you most interested in receiving? Most people want just one antenna pointed in one direction and that's it. If that's you then Larry's recommendation for the HD7694P pointed to Sutro/San Bruno should be fine. You don't have line-of-sight to the transmitters though so the antenna must be mounted on your roof and should not be looking through thick trees or pointed into the side of another building. The stations in Walnut Grove and Fremont are very weak and would require a substantial antenna system with a rotor to have any chance of receiving them.

How long of a coax run will you have? How many TVs will the antenna feed? Your answer to these will determine if a preamp or distribution amp would be helpful.

Chuck
 

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No, no slope here... normal blob with a peak near the middle.
This is nice to hear that there is not a slope in your direction. The FCC updated the call letters today for KTVJ-LP to be KTVJ-LD and granted the license and updated the city of license to San Rafael.
I'm working on getting everything lined up to construct K02QX-D on May 22nd on Mt. Chual / Mt. Loma Prieta.

Also, the OMI stations are switching to Dynamic PSIP instead of Static PSIP. I should get the new software to do this on Monday. Then, I'll have to figure out how to keep the program data current.

Blessings,
Keith
 

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Ben's Preamps

Ben sent me some preamps to test, including a couple of really old ones. Here's a summary:

RCA AMP1450R

Gain High VHF/UHF - 12-13 dB
Noise Figure VHF - 4.4 - 4.6 dB
Noise Figure UHF - 4.1 - 4.8 dB
IP3 UHF - +25 dBm

This amp is basically a clone of the discontinued Winegard HDP-269 except that it has an FM trap. The gain is about 1 dB higher and the Noise Figure is about 0.5 dB higher than the Winegard. As I noted elsewhere, the RCA TVPRAMP1R is a clone of the Winegard AP8700 except that it has the VHF separate input. The noise figure isn't very good but with low gain and low-moderate IP3 it might be okay for an attic antenna if you're on a tight budget.


Winegard Boost LNA200 - I thought I was getting an LNA100 so I didn't extensively test this. A few checks showed it was the same as the other LNA200 I tested...... not very good. I don't recommend it for anything.


Old Preamps

Clear Vue GI-099004 - This is one of those amps that can use the house wiring as an antenna. I tested the regular 75 ohm input.

Gain Low Setting - 5.6 - 13.2 dB
Gain High Setting - 12.0 - 15.1 dB
Noise Figure UHF Low Gain - 12.0 - 15.1 dB (Really bad. Forget the low gain.)
Noise Figure UHF High Gain - 4.2 - 5.3 dB
IP3 - +17.9 dBm (Poor)

I wouldn't recommend using this amp for anything. The AMP1450R is a much better replacement.


Video Master AB415 - This must be really old. It is 300 ohms in and out. I had to use my calibrated 300:75 baluns to test it. The numbers below have the balun losses subtracted out.

Gain VHF/UHF - 12 - 16 dB
Noise Figure UHF - 3.4 - 4.9 dB
IP3 - +14.7 dBm (This is very poor.)

This amp has no filters of any kind. Due to its very poor IP3 I wouldn't even use it in a 300 ohm system.

While I'm at it I tested a very old (1980's vintage) Winegard PA-8275 (yes PA-8275, not AP8275). It's in a metal box with all discrete components inside. It has separate VHF and UHF paths. Looks like the UHF input device is a FET and the VHF input device is a transistor.

Gain Low VHF - 30 - 32 dB (ouch!)
Gain High VHF - 23 - 26 dB
Gain UHF - 27 - 33 dB
Noise Figure Low VHF - 4.3 - 5.9 dB
Noise Figure High VHF - 4.3 - 5.4 dB
Noise Figure UHF - 2.8 - 3.1 dB
IP3 Low VHF - +32dBm
IP3 High VHF - +31dBm
IP3 UHF - +28dBm

This preamp was spec'd at NF VHF 2.0dB and NF UHF 1.0 dB. I've yet to find a preamp that meets its claimed noise figure. I'm beginning to think that the manufacturers simply use the input device noise figure spec and never measure the final product.

Chuck
 

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Ben sent me some preamps to test, including a couple of really old ones. Here's a summary:
RCA AMP1450R
Video Master AB415 - This must be really old. It is 300 ohms in and out.
Chuck
So here's what I used those amps for.
RCA AMP1450R .........KEMO,KTLN, KRCB on a attic antenna sweet spot found by "probing" .... KEMO is -15dm NM on the tvfool report. Works ok.
Winegard Boost LNA200.....Nothing, ... I will return it. Sold at Home Depot.
Video Master 300 ohm ..... Was used on the "Gold Double UHF indoor Bowtie" models sold in the 1970s & 1980s. Now headed to the next e-waste event :rolleyes:
Clear vue amp (house wiring) .....Temporary setups such as backyard tv for projects, etc .... When you just want to run a power cord to a spot.
It's hit or miss if it works on the channel you want to watch. .... Time to toss this one as well ...:eek:
Thanks for the testing report!
Ben
 

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It's the Winegard HD7698P which has good gain for both VHF for channels 7 and 11, and for UHF for all of the rest of the stations. Or you need a good 10 element yagi for VHF like the AntennaCraft Y-10-7-13 and a Channel Master CM4228 or Antennas Direct 91XG for UHF.

Good luck!

Larry
Just assembled my Winegard, big sucker, hope to try it tomorrow. Is there a rule of thumb on how long a coax cable can be before amplification is necessary? And if one type of coax can go longer than another how do I tell what type I have?
 

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Just assembled my Winegard, big sucker, hope to try it tomorrow. Is there a rule of thumb on how long a coax cable can be before amplification is necessary? And if one type of coax can go longer than another how do I tell what type I have?
You should use RG-6 coax cable. You can go up to 100 feet without sufficient loss, but you should use the shortest run possible between your antenna and your TV. Only use a preamp if you have weak signals. Closer stations can overload the TV when a preamp is used, making it worse overall. A preamp goes up at the antenna, not at the TV end of the coax.

Let us know what you get tomorrow. I hope you get a nice surprise when you do your scan!

Larry
 

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Just assembled my Winegard, big sucker, hope to try it tomorrow. Is there a rule of thumb on how long a coax cable can be before amplification is necessary? And if one type of coax can go longer than another how do I tell what type I have?
Hmmmm..... I went back and looked at your TV Fool report and the picture of your house in the woods. I must have got sidetracked before to have not made a comment. I hope I'm wrong but I'm not optimistic. If you had those Noise Margins and a clear shot to the first edge I'd say you might have a chance. UHF+Trees=Terrible Multipath. If you get anything at all I'll bet it'll be 7 and 11.

Chuck
 

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At 6:40 pm I just found K03HY back on the air and KTVJ 12 gone. Keith must be working up at the Mt. Tam site.

Larry
 

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Sure enough. KCSO is gone again. I wonder what's going on?
Chuck
At 11 o'clock tonight channel 3 was still on and 4 was off. Now at 12:20 am neither station is on the air. We'll have to see what happens tomorrow.
 

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Just assembled my Winegard, big sucker, hope to try it tomorrow. Is there a rule of thumb on how long a coax cable can be before amplification is necessary? And if one type of coax can go longer than another how do I tell what type I have?

Too muddy to get up the hill to my cabin today so I am playing with the new Winegard antenna at my house in Novato. Depending where I point it I'm pulling in stations from Santa Rosa, Walnut Grove, San Jose and of course Sutro. Basically what I am learning is that what I get from one area is pretty much available on another station from another area (major network wise). I also get some channels from a transmitter but not others, which are putting out a weaker signal I assume.

Questions: Do I point the antenna in the direction it shows on the circle of the TV Fool report (assuming the x y axis of that report is roughly equal to what google maps shows as NSEW)? Second, if there is a hill or tree in the direction I want to point should I aim slightly around that obstacle?

I get about 45 channels when I point it south, about 20 pointed east and 10 north. I'm really just killing time and learning a little bit until I can try it at the cabin (tomorrow hopefully), and if I get one or two channels there I will consider it a success.

Thanks for the replies ^^

Paul
 

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Questions: Do I point the antenna in the direction it shows on the circle of the TV Fool report (assuming the x y axis of that report is roughly equal to what google maps shows as NSEW)? Second, if there is a hill or tree in the direction I want to point should I aim slightly around that obstacle?

You should point in the direction given by your TV Fool report, table or the compass.

Signals do not go around hills or trees. It would be nice if they did. :) They refract over the top, if they can.

Chuck
 

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Too muddy to get up the hill to my cabin today so I am playing with the new Winegard antenna at my house in Novato.
Questions: Do I point the antenna in the direction it shows on the circle of the TV Fool report
Thanks for the replies ^^

Paul
What I would do is set your tv to "channel 7", then point to San Francisco until it comes in best, ..... Then do a "scan"

Usually if your antenna does not have a view of .. "Clear sky" without shade & trees,..... UHF reception is going to be a real challenge.
In that case, "probing" for signal is a last chance.
If the ground is clear of brush, with better views of the sky, .... a lower elevation possibly.
Let us know what happens,
Ben
 

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If I was able to get the antenna up above the trees at the cabin it would be 200 ft. of coax just to get back to the ground but it would give me a pretty clear sight in a couple of directions (unfortunately not south). Could the degradation from the coax length be overcome?

Thanks Chuck
 

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If I was able to get the antenna up above the trees at the cabin it would be 200 ft. of coax just to get back to the ground but it would give me a pretty clear sight in a couple of directions (unfortunately not south). Could the degradation from the coax length be overcome?

Thanks Chuck
The best location "is the location" with nothing in front of the UHF yagi elements (very small ones) for 100+ feet, and the elements see blue sky.
 

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If I was able to get the antenna up above the trees at the cabin it would be 200 ft. of coax just to get back to the ground but it would give me a pretty clear sight in a couple of directions (unfortunately not south). Could the degradation from the coax length be overcome?

Thanks Chuck
Yes, it can be. Let's say you needed 300' of RG-11 which is 3.4 dB loss per 100' at channel 51. You'd also want to have a distribution amp such as the CM341x series in the house because it has a lower noise figure than the TV.

I have a rule of thumb to use for determining the required preamp gain to not degrade the preamp noise figure by much. It is:

Coax Loss + First amp Noise Figure + 8 dB

In this case that would be 10.2 + 2.5 + 8 = 20.7 dB. It's no problem getting a preamp with that amount of gain.

I have a total of 575' of coax to my UHF antennas. 480' is low loss CATV hardline with 1.8 dB loss/100' at channel 51, 75' of RG-11 and 20' of RG-6. The total loss is 15 dB. I have a second set of UHF antennas on a 2nd tower and that coax run is 685' and it still works fine with a Tin Lee 30 dB gain preamp.

It's not the coax loss so much that's the problem, it's getting the antenna mounted on the top of a tree. ;) Even if you were to do that, aren't you on the wrong side of Mt. Tam? You should run your TV Fool report for the proposed location using the height above the trees.

Chuck
 

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Thanks Ben and Chuck. I have a monkey for a neighbor. But yes, Tam is smack dab between me and SF, along with my own hillside and the worst of the trees. I guess I'm hoping for something from the east or north, or from the Tam transmitter. Even then I have Mt. Burdell to the north and Big Rock ridge to the east, albeit a bit further away and less substantial than Tam.

I just loaded up the new antenna to out there tomorrow, it's longer than my truck!
 

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I guess I'm hoping for something from the east or north, or from the Tam transmitter. Even then I have Mt. Burdell to the north and Big Rock ridge to the east, albeit a bit further
Tv does not work like cell phones, ... with towers and boosters everywhere.
No network programming from Mt. Tam .... Except church type of tv channels.... plus all the home shopping channels you want... etc.
You're not going to watch "The Simpsons" :eek: from Mt. Tam ....sorry

You need a reasonable line of sight to Sutro tower in San Francisco
 
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