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Old 18-Sep-2016, 6:18 PM   #21
Tower Guy
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Quote:
Originally Posted by 760side View Post
I purchased the DB8 6-7 years ago and it was one of the highest rated OTA antennas at the time.
I'd try moving the UHF antenna up or down 6 inches at a time to see if you can find a hot spot for NBC. Read the siting section of the hdtvprimer.com for background information.
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Old 8-Oct-2016, 10:00 PM   #22
760side
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so just to check in, Ill probably pick up a 91xg and replace the db 8.

Will a cm 7777 or 7778 be helpful or just the antenna replacement?

Also would it be worth it to point to any of the nbc stations to the north? Im not tied to getting just the San Diego stations. I just want a solid signal with minimal to no drops.
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Old 9-Oct-2016, 1:39 AM   #23
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so just to check in, Ill probably pick up a 91xg and replace the db 8.
I think it is worth a try if you are willing to experiment, but I can't guarantee it will improve your reception. The 91XG does have a gain peak at the high end which pulls ch 40 up, and the front end can be tilted up to catch the signals coming down from the peak.
http://www.hdtvprimer.com/antennas/comparing.html

Look at the Net Gain curves M and P for the 91XG and DB8.

Because the KNSD signal is scattered by the mountain peak, the wave front of the signal is non-uniform, so it will have hot spots and cold spots. It is worth the trouble to try slightly different locations as suggested by Tower Guy, not only of height but also left-to-right horizontal movement. Antenna installers call it "walking the roof."
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Quote:
Will a cm 7777 or 7778 be helpful or just the antenna replacement?
The 7778 has about the same gain as your CPA19 unless it is defective. The 7777 has more gain and might help.
Quote:
Also would it be worth it to point to any of the nbc stations to the north?
I doubt it. KNBC is a LOT weaker.
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Last edited by rabbit73; 9-Oct-2016 at 2:12 AM.
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Old 9-Oct-2016, 3:29 PM   #24
Nascarken
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The antennas Direct 91XG with a channel master 7777amp I say that you should give it a try you might be surprised on what you receive and I suggested that the Antenna be 10Ft high OFF the roofs line AND a A G L of 30,and don't FOR GET to ground the antenna and use a good RG6 CABLE 18Gage solid copper not copper clad steel Cable for best performances in receiveing channels good luck and be safe on the roof

Last edited by Nascarken; 9-Oct-2016 at 3:38 PM.
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Old 9-Oct-2016, 6:50 PM   #25
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Ive ordered the 91xg and will update once I get it set up.
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Old 9-Oct-2016, 7:29 PM   #26
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Don't FOR GET THE channel master 7777amp you will need it
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Old 17-Oct-2016, 3:07 AM   #27
760side
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looks like the antenna did the trick

Heres my reading on knsd with the old DB8

Screenshot_2016-10-15-12-35-34.jpg


And heres the reading after connecting the HDB91x

Screenshot_2016-10-15-13-20-52.jpg

I didnt have any extended drops in the evening like Ive had with the DB8.

Thanks for everyones help.
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Old 17-Oct-2016, 3:42 AM   #28
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We'll good day 760side good to see everything is going well with the HDB91xg did you have to buy an amplifier well good luck and have a good day
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Old 17-Oct-2016, 7:06 PM   #29
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Quote:
Originally Posted by 760side View Post
Heres my reading on knsd with the old DB8

Attachment 2382


And heres the reading after connecting the HDB91x

Attachment 2383

I didnt have any extended drops in the evening like Ive had with the DB8.

Thanks for everyones help.
Thanks for the update; sounds like a big improvement.

Did you tilt the front end of the HDB91X up?

Attached Images
File Type: jpg 760sideTVF_DB8vsHDB91X.jpg (74.3 KB, 746 views)
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Last edited by rabbit73; 17-Oct-2016 at 7:13 PM.
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Old 25-Oct-2016, 1:45 AM   #30
Nascarken
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Hi rabbit 73 It looks like the DB8 IS a dog over the H D B 91XG DO YOU THINK IT IS BECAUSE YOU CAN'T PUT A N, A G L ON IT OR IS IT JUST A DOG OVER ALL
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Old 25-Oct-2016, 3:12 PM   #31
rabbit73
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The DB8 is NOT a dog. When he bought it years ago, it was one of the best UHF antennas available.

Every reception location is different. The goal is to pick the best antenna for THAT location.

It is primarily the tilt feature of the 91XG and HDB91X that makes a difference at his location. The DB8 doesn't have a tilt adjustment; it would be a custom modification.

When I was making antenna tests at a location that had a clear LOS path across water, I found that tilting my 4-bay UHF antenna increased the signal strength.

Attached Images
File Type: jpg Antenna Test Site5_2.jpg (78.0 KB, 2636 views)
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Last edited by rabbit73; 2-Nov-2016 at 2:52 AM.
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Old 2-Nov-2016, 12:58 AM   #32
760side
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I did a slight tilt upwards and I also replaced one of the cables between the tv and the pre-amp.

It was an old cable that came with my hd homerun and it was replaced with a homemade cable with a press on connector.
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Old 2-Nov-2016, 2:26 AM   #33
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OK; do you think those changes made the improvement?

Which change do you think made the most difference, the tilt or the cable?
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Last edited by rabbit73; 2-Nov-2016 at 2:51 AM.
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Old 2-Nov-2016, 3:39 AM   #34
760side
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I think the antenna with the tilt made the most difference because my signal is much stronger and consistent. The new cable made a difference in my signal to noise ratio. I was getting varying readings with my SNR after a couple days with the new antenna. Some times it would be stable SNR and others it would fluctuate. So I decided to do some basic troubleshooting like taking a splitter out of the equation between the wall plate and the pre-amp. I figured I might as well make a new cable since I have the extra cable and who knows the quality of cable HDHomerun packages with their tuners.
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