Question about attic install

[deeciple]

Hi all,

I have a RCA Outdoor Yagi antenna that I am currently using very successfully outdoors. Unfortunately I have to move it to an attic install and I found that I have radient barrier insulation on all but the west wall of the attic. Luckily I have to aim my antenna roughly west by northwest so it works out well.

I attached a pic (not of my actual attic) as an example of my situation. My question is, is that wall being free of the radient barrier enough to expect good results for an attic install?

Thanks,
Ken

[rabbit73]

Originally Posted by deeciple

Hi all,
My question is, is that wall being free of the radient barrier enough to expect good results for an attic install?

Thanks,
Ken

Hello, Ken.

It is fortunate that there is no radiant barrier in the signal path, but there will still be some signal attenuation from the building construction.

Without a signal report from you for your location, you will have to make some tests to see if you need a preamp.

[deeciple]

Hi rabbit73,

Thanks for your reply. I am hoping that any signal loss from the building materials will be offset by the additional height (I am going from about 12' to about 30').

Given that the roof-line is narrower on top and with adjacent radiant barrier, does it make more sense to mount the antenna closer to the floor to take advantage of the wider part of the wall or does it make a difference?

here is a link to my signal report:

http://www.tvfool.com/?option=com_wr...9038763bf86c44

That wall faces northwest. I almost think the builders planned for an attic antenna

Thanks,
Ken

[rabbit73]

Originally Posted by deeciple

here is a link to my signal report:

http://www.tvfool.com/?option=com_wr...9038763bf86c44

That wall faces northwest. I almost think the builders planned for an attic antenna

Thanks for the report. TVFool is using an old database to generate reports, so I did an estimated report for your location using rabbitears.info:
https://www.rabbitears.info/searchma...tudy_id=253085



You can do a more accurate report for your location at this site (I use coordinates from Google maps):
https://www.rabbitears.info/searchmap.php

You have a few signals that should be OK with an attic antenna but they are not all in exactly the same direction.

[deeciple]

Hi rabbit73,

I got the antenna installed in the attic today. I did take a hit on signal level so I added an amplifier that I had from an RCA DN010165 indoor antenna. think it may be introducing noise as the signal quality is not better but the signal level does improve some.

Do you think a better amp would improve signal level and quality? If so, can you recommend some good low noise amplifiers that I could use in this case?

Thanks,
Ken

[rabbit73]

Originally Posted by deeciple

I got the antenna installed in the attic today. I did take a hit on signal level so I added an amplifier that I had from an RCA DN010165 indoor antenna.

Do you think a better amp would improve signal level and quality? If so, can you recommend some good low noise amplifiers that I could use in this case?

What channels do you need (by callsign) and what channels are you getting OK now?

Please do a signal report for you location at rabbitears.info using the coordinates of your antenna.
https://www.rabbitears.info/searchmap.php

Even better, are you willing to give me your address and coordinates of your antenna from Google maps in a PM for privacy, so that I can see how the signal lines reach your antenna?



Thank you for the photo of your antenna in the attic. I see a black pipe or duct in front of the antenna. If it contains metal or foil it might block the incoming signals.



I think for now, the RCA amp is good enough for a test. What you need to do is put your antenna in the best location possible in your attic so that the best signals possible are coming out of your antenna before amplification. An amp can make the signals stronger, but it can't turn a poor quality signal into a good quality signal.

[deeciple]

That black thing is a duct. Not sure if it has foil inside or not. Unfortunately I am limited where I can put the antenna as the attic has very few floorboards so I have to balance on the joists. I tried to get as close to th wall as possible and low enough to take advantage of the wider portion of the wall.

I am getting about 35 channels now (all the networks plus some others). They are all coming in at about 70 to 85% signal level with the amp and about 50 - 65% signal quality.

I ordered this pre-amp because it is supposed to have a very low noise floor. It has a 18db gain. Hopefully this will be enough to boost the signal to acceptable levels.

Only the ABC affiliate is coming in poorly. The quality is at about 45% to 50% and it's very spotty reception.

Here is the signal report.

[rabbit73]

Originally Posted by deeciple

I tried to get as close to the wall as possible and low enough to take advantage of the wider portion of the wall.

I am getting about 35 channels now (all the networks plus some others). They are all coming in at about 70 to 85% signal level with the amp and about 50 - 65% signal quality.

Thank you for the signal report. It gives me a better idea about how the signals arrive at your antenna in the NW end of the attic.

Only the ABC affiliate is coming in poorly. The quality is at about 45% to 50% and it's very spotty reception.

That is to be expected. WSOC is coming from a different direction (the North) and there are many trees in the signal path that weaken the signal and reduce its signal quality.

[deeciple]

This is odd. I connected the new pre-amp today and it DID give me a great boost in signal level and quality. On average I gained about 10 to 15% in both signal level and quality with some stations upwards of 99%. I don't believe I am over-driving any of the channels but I noticed that they are all glitchier than with the cheap RCA amp, even though accordin to the levels they should be rock solid.

This may sound silly but is there a "break-in" period for these amps Any other reason why the RCA amp would yield more stable picture when the Winegard amp gives better signal levels?

[rabbit73]

Originally Posted by deeciple

That black thing is a duct. Not sure if it has foil inside or not. Unfortunately I am limited where I can put the antenna as the attic has very few floorboards so I have to balance on the joists. I tried to get as close to the wall as possible and low enough to take advantage of the wider portion of the wall.

I used to put sheets of plywood down in the attic so I wouldn't fall through.

[deeciple]

Lol, that's good. Maybe for a future project. Any idea why the Winegard amp would yield the glitchier reception if the levels are so much better?

[rabbit73]

Originally Posted by deeciple

This is odd. I connected the new pre-amp today and it DID give me a great boost in signal level and quality. On average I gained about 10 to 15% in both signal level and quality with some stations upwards of 99%.

What device is giving you those percentage readings of signal strength and signal quality?

I don't believe I am over-driving any of the channels but I noticed that they are all glitchier than with the cheap RCA amp, even though according to the levels they should be rock solid.

"Glitchier" indicates a reduction of signal quality. It is possible to have a strong signal with poor quality (low SNR or increased errors) from possible overload or multipath from the signal passing through trees or attic clutter.

Is it worse on windy days?

This may sound silly but is there a "break-in" period for these amps Any other reason why the RCA amp would yield more stable picture when the Winegard amp gives better signal levels?

A "break-in" period is not usual unless the preamp is defective.

Your new preamp has about 12 dB more gain than the RCA amp.

[deeciple]

Originally Posted by rabbit73

What device is giving you those percentage readings of signal strength and signal quality?

I have the antenna/amp connected to an HD Homerun.

Is it worse on windy days?

Now that you mention it, we did have some storms pass through the area earlier in the day yesterday. It may still have been a bit windier than usual when I tested in the evening.

Your new preamp has about 12 dB more gain than the RCA amp.

Thanks, I will have to observe and test over the next few days. Do you happen to know the signal/noise ratio on the RCA? I searched but didn't find anything.

[rabbit73]

Originally Posted by deeciple

I have the antenna/amp connected to an HD Homerun.

The HDHR GUI can be very useful; it gives Signal Strength, Signal Quality, and Symbol Quality.
When the Signal Strength reaches 100%, that is equivalent to 0 dBmV (-49 dBm). That's about the level antenna installers and cable guys aim for at a wall plate outlet for a TV. However, TV tuners can handle signals much stronger than that without a problem. But if you talk to a SiliconDust tech, he will tell you that you have overload at 100%. It seems that HDHR tuners have a tendency to overload more easily than TV tuners.

Signal Quality, which is similar to SNR, must be at least 50%. This is equivalent to about an SNR of 15 dB.

Symbol Quality is the inverse of Uncorrected Errors. 100% Symbol Quality is no Uncorrected Errors. You must have 100% Symbol Quality for reliable reception.

I did a thread about that topic:
SiliconDust Signal Strength Conversion Chart
https://forum.tvfool.com/showthread.php?t=16691

Now that you mention it, we did have some storms pass through the area earlier in the day yesterday. It may still have been a bit windier than usual when I tested in the evening

When the wind blows, the tree branches sway, which chops up the signals passing through.

I have a tree outside my window that messes with the signals when the wind blows, causing increased signal errors.



Video of signal affected by wind in tree. I use VLC Media Player. Made using GE 34792 antenna; GE 29884 does better.
Download and view now:
https://www.dropbox.com/s/ig3va499k2...Path4.mp4?dl=0

Download now, view later:
https://www.dropbox.com/s/ig3va499k2...Path4.mp4?dl=1

Thanks, I will have to observe and test over the next few days. Do you happen to know the signal/noise ratio on the RCA? I searched but didn't find anything.

Preamps are not rated in SNR, they are rated in Gain, Noise Figure, and MAX Input. Your RCA amp probably has a gain of about 12 dB, but RCA doesn't publish those specs.

[deeciple]

Wow, so much useful information! Thank you so much for taking the time to put this together. Based on the specs you posted and after researching a bit myself, it appears the Winegard LNA-100 outperforms the LNA-200. Seems like a simpler hookup for my needs too, so I ordered one to compare.

Best regards,
Ken

[deeciple]

UPDATE:

Well the storms passed and there is no more wind. What a difference! No more glitches and look at the signal:







I never would have thought that a little wind could make so much difference.
Thanks again for your help!

Best regards,
Ken

[rabbit73]

Originally Posted by deeciple

UPDATE:

Well the storms passed and there is no more wind. What a difference! No more glitches and look at the signal:

I never would have thought that a little wind could make so much difference.
Thanks again for your help!

Best regards,
Ken

Thanks for the update and the GUI images, Ken. Those signals look good.



I had the wrong house. I think this is the right house. The end of the attic faces a little more to the north and the trees are a little further away.

[bobsgarage]

Originally Posted by deeciple

UPDATE:

Well the storms passed and there is no more wind. What a difference! No more glitches and look at the signal:

[IMG]http://forum.

I never would have thought that a little wind could make so much difference.
Thanks again for your help!

Best regards,
Ken

Watching this thread. Rabbit is extremely helpful, isn't he?

I never found out the reason why you don't have your antenna on the roof. But if you have to deal with this wind every time it's going to drive you nuts. If it's been discussed forgive me but the best thing you can do is re-site to your antenna.

I like reading these help requests and seeing the solutions.

Also, if I could make a suggestion. I found the Winegard lna-200 to be very noisy which attenuate your signal. If you're into experimenting with pre amps, try the Kitz Tech KT-200 low noise preamp.

https://www.kitztech.com/kt200.html

[deeciple]

Yes, Rabbit gave me a ton of great advice!

Unfortunately my HOA now prohibits visible antenna's and satellite dishes so the attic mount was my only option. Thankfully the storms that passed through the southeast over the past week or so are unusual. Most of the time it's pretty calm out here.

Thanks for the amp recommendation. I will have to look at that one.

Best,
Ken

[rabbit73]

Originally Posted by bobsgarage

Watching this thread. Rabbit is extremely helpful, isn't he?

Thank you, Bob.

Also, if I could make a suggestion. I found the Winegard lna-200 to be very noisy which attenuate your signal.

He ordered the LNA-100.