Suggestions for improvements?

[760side]

So ive had solid reception overall but there are 2 channels that give me fits, 15.1 and 39.1. Of course 39.1 is the one we watch the most and causes the most spousal frustration with its drops. Are there any UHF antennas that would do a better job or any other improvements i could make?

heres my map

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3de2cbcabff3538b

set up is below:
UHF Antenna (antennas direct db8)
|
Radio Shack splitter/joiner -->cpa-1---wall plate--Power Supply Inside-->TV
|
VHF Antenna (antenna craft yagi vhf antenna)

[ADTech]

1. Where/how is the DB8 mounted?
2. What exact direction is it aimed?
3. What is out in front of the DB8, for example, trees, buildings, etc?

There is a little bit of improvement available by swapping from a DB8 to the newer "e" version as far as peak forward gain is concerned, but situations such as yours usually suggests a sub-optimal mounting situation that should be investigated first.

[Tigerbangs]

Looking at your TVFool.com report shows that KNSD, your NBC station lies in a direction that is 25 degrees off from your ABC and CBS stations. That, combined with KNSD's weak signal strength at your house, would be enough to cause problems with KNSD.

The most obvious solution would be to mount your antenna array on a rotator, which would allow you to fine-tune the antenna between the local transmitters. If we assume that your TV set has a signal quality meter, you could turn the antenna from indoors to maximize signal quality for all your channels.

[rabbit73]

cpa-1Huh? Do you mean CPA-19?

Radio Shack splitter/joinerWhich one? There is a right one and a wrong one.

He doesn't need to aim between. VHF is 159 deg magnetic, and UHF is 137 deg magnetic.

That hill in the signal path for KNSD doesn't help.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3de2cbcabff3538b%26t%3dALLTV%26n%3d8

[760side]

i have a cpa 19

Im using a radio shack joiner since i have a vhf and uhf antenna.

I have the vhf pointer at the towers, approx 159 magnetic, for channels 8 and 10 those come in solid.

the db8 is pointed approximately 137 magnetic.

both antennas are mounted about 30-40 feet off the ground.

[rabbit73]

i have a cpa 19
OK, good if it is working properly.
Im using a radio shack joiner since i have a vhf and uhf antenna.That doesn't answer my question. Some people try to use a splitter in reverse as a joiner and some people use the correct device, a UVSJ.

http://forum.tvfool.com/attachment.php?attachmentid=2243&d=1471963927

You didn't answer ADTech's question
3. What is out in front of the DB8, for example, trees, buildings, etc?

Assuming the path is clear in front of the DB8, you should be receiving those two channels OK. If not, something else is wrong, but we haven't discovered it yet.

[760side]

Im using that exact UVSJ.

There isnt much immediately in front of the the DB8. Like I said its mounted about 30 feet off the ground.

Maybe 1-2 miles south there is a small mountain range which is probably cause for some interference but not sure.

[Nascarken]

HDB91X a lot cheaper than the DB8 and I think it works better then the DB 8

[760side]

Would replacing the DB8 with a 91xg improve my reception?

Is there any other data or pictures I could provide that would help?

[Nascarken]

Yes SOLID signal.COM the ANTENNA performance is a s m, the price of the HDB91x is $45,dollars shiped but hurry the sale runs out SOON, I HAVE 2 stacked with a channel master 7777,amp,I receive channels 80Miles with no dropouts in heavy rain or snow signal strength is 70,antennas are 80Ft high,

[rabbit73]

Would replacing the DB8 with a 91xg improve my reception?I'm not convinced that it would at this point.

The only advantage to the 91XG (or the HDB91X clone) is that you can tilt the front end up to catch the signals coming from the peak of the hill. It made a difference for one user I helped.
Is there any other data or pictures I could provide that would help?A photo of your antenna system and a photo of what the antenna "sees" when it is aimed at 137 degrees magnetic might help.

and I think tilting the front of a UHF antenna up might help:

http://forum.tvfool.com/attachment.php?attachmentid=2251&d=1472156169

TVFOOL terrain profile for KNSD:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3de2cbcabff3538b%26t%3dALLTV%26n%3d8

[Nascarken]

We'll I say that if you put the ANTENNA up 5Ft more and WITH the 91 and a channel master 7777amp I think it will be able to receive all in all Good luck!!

[760side]

Ill try and post some pictures this weekend. Im heading out of town today but will be back sunday.

[760side]

Heres the pictures of my setup, the direction the antenna is pointed and the HDHR signal reading after a sight adjustment...and I mean maybe rotating 1/4 of an inch

[rabbit73]

Thanks for the photos. The HDHR readings indicate that NBC should look good on the TV; does it, or do you still have a problem?

http://forum.tvfool.com/attachment.php?attachmentid=2322&stc=1&d=1474151295

[760side]

yes its fine for the time being but usually around 5 or 6 at night the reception starts to break up every now and then.

[rabbit73]

What is that in the photo, is it the VHF yagi?

around 5 or 6 at night the reception starts to break up every now and then.Could be from a temperature inversion that helps the propagation when it is hot, but when it cools down the signal is weaker.

I still think tilting the aim of the antenna up might help. It would be a custom modification for the DB8, but there is a tilt adjustment on the 91XG and the HDB91X that allows you to tilt the front of the antenna up.

[760side]

The 2nd antenna is a vhf yagi that pulls in channels 8 and 10 solidly. Yes i know it needs to be more level but I have no problems with those channels.

I will look into tilting the antenna up.

[Nascarken]

That's why I suggest the 91 XG instead of the DB 8 and the DB 8 is a wind sale and a lot of money for what it is and you can not t I 'll t ,it with OUT Mickey mousing it, like I say about the DB 8 is a piece of junk in my book and the vhf ANTENNA THAT u have is a good pick and I don't no why you did not BUY a 91XG that wood OUT performs the DB 8 and the price TO well good luck and be safe on the roof

[760side]

I purchased the DB8 6-7 years ago and it was one of the highest rated OTA antennas at the time.

[Tower Guy]

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.

[760side]

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.

[rabbit73]

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."
http://forum.tvfool.com/showpost.php?p=56525&postcount=34
http://forum.tvfool.com/showpost.php?p=56526&postcount=35
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.
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.

[Nascarken]

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

[760side]

Ive ordered the 91xg and will update once I get it set up.

[Nascarken]

Don't FOR GET THE channel master 7777amp you will need it

[760side]

Heres my reading on knsd with the old DB8

2382


And heres the reading after connecting the HDB91x

2383

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

Thanks for everyones help.

[Nascarken]

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

[rabbit73]

Heres my reading on knsd with the old DB8

2382


And heres the reading after connecting the HDB91x

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?

http://forum.tvfool.com/attachment.php?attachmentid=2386&stc=1&d=1476731160

[Nascarken]

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

[rabbit73]

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.

http://forum.tvfool.com/attachment.php?attachmentid=2413&stc=1&d=1477409149

[760side]

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.

[rabbit73]

OK; do you think those changes made the improvement?

Which change do you think made the most difference, the tilt or the cable?

[760side]

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.