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Discussion Starter · #1 ·
Hi All-

We've got an RCA ANT751R antenna mounted in our attic and are currently getting excellent reception, even in the hi VHF range. We're looking into getting solar panels to eliminate our electricity bill, but I'm concerned they might interfere with our OTA reception.

The reason I did not mount the antenna on our roof is that we've got lightweight concrete tiles, and most roofers won't even go up on our roof for fear of breaking tiles. Plus it's steeper than I'm comfortable walking on.

The antenna is facing at 205 degrees, which unfortunately points it out the south side of our house, where the solar panels would be. If we place the solar panels slightly below the antenna's level, or to the side of where it is pointing, would they still likely interfere with our TV reception?

I've read that some people think the inverters can cause interference. For those that know solar, would there be a difference between microinverters (under each panel) or optimizers for each panel with a central inverter placed on the north side of the house?

Thanks.
 

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Welcome, tigerucla:

Yes, it is possible that you will have interference to TV reception from your solar system, but testing will be required to see how severe it might be.

The fact that you are using the RCA ANT751 antenna seems to indicate that you are in a strong signal area which will help. We would like to see your tvfool report if you can do that.
http://www.tvfool.com/index.php?option=com_wrapper&Itemid=29

You need 5 posts before you can post an active link, so you can give us the last part of the link after the?, or have the moderator post it for you after you request it in a PM.

Interference from your system can be radiated, conducted, or both.

The April 2016 QST magazine has a good article on interference; it is worth the trouble to hunt it down. It is the cover article which says Can Amateur Radio and Solar Power Coexist?
Can Ham Radio and Solar Power Coexist? by Tony Brock-Fisher, K1KP, pp 33-37

This is a good blog on the topic:
The solar saga - part 1: Avoiding interference (Why I did not choose microinverters!)
http://ka7oei.blogspot.com/2016/03/the-solar-saga-part-1-avoiding.html

How To Reduce Electromagnetic Interference in Solar Systems
https://www.solar-electric.com/reducing-electromagnetic-interference-pv-systems.html/

Home Power magazine has a Q&A column where you can ask your question.

If your case is severe, it might be necessary to move the antenna as far away as you can from the solar system, ground the coax, and run the TV on a sine wave inverter. I have used an Exeltech XP-125 to run a small TV on battery power. Modified sine inverters are really modified square wave inverters.
 

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I'm thinking there would be substantial interference.
 

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Here is a generic report centered on Douglas Blvd near the Granite Bay Branch Library:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=e2cbedc150bd13

The signals are very strong at that location.

a short link for that report is
?option=com_wrapper&Itemid=29&q=id%3de2cbedc150bd13


The short link has a space between the last two digits; that is normal. We will close the space when reconstructing your report if you give us the short link from a report that you do for your location.

As the sticky says:
http://www.avsforum.com/forum/25-hd...all-antenna-threads-tvfool-info-1st-post.html
 

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If someone says that it would "definetely" interfere, would you not choose to proceed with solar over an attenna? :D


It's best to wait and see what happens. IME, all situations are different.
 

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The reason I did not mount the antenna on our roof is that we've got lightweight concrete tiles, and most roofers won't even go up on our roof for fear of breaking tiles. Plus it's steeper than I'm comfortable walking on.
In that case, you may not be a candidate for solar panels, so the point may be moot.

And this is where you generate enough posts to post links, etc.:
http://www.avsforum.com/forum/46-post-testing-area/

Welcome aboard.

Michael
 

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Discussion Starter · #7 ·
Thanks for all the replies. I apologize for not putting my location in the title. I figured it was a generic question. My bad.

Here's my TV fool report: ?option=com_wrapper&Itemid=29&q=id%3de2cb9f2df4236d

I've attached a roof view: green circle is where the antenna is pointing; blue circle is possible alternative antenna location; black rectangles are most likely solar panel placements; yellow triangles are possible panel placements.



So from reading the links, it looks like both microinverters and optimizers can cause interference. So it sounds like I should ask the solar guys about using an old fashioned string inverter. A string inverter would be close to where the alternate antenna location would be, if that's an issue.

Would the panels themselves block the signal? If so, how high above the black panels would the antenna need to be? How far to the side of the yellow panels?

To answer Ratman's question, if solar and OTA cannot coexist, then we may not do solar, since we're on the fence about it anyway.
 

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To answer Ratman's question, if solar and OTA cannot coexist, then we may not do solar, since we're on the fence about it anyway.
Ah! The sacrifices we make in life for watching TV.
 

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You should be able to Remount the Antenna OUTDORS, WITHOUT having to go on the roof....such as one of the fol. mounts attached to the SIDE of the house....and be sure to run a GROUNDING wire to the mount. IF Tiles overhang so you can't attach Directly to the LEDGERBOARD, you might have to build a small wooden offset structure:
http://www.dtvusaforum.com/threads/48566-Christmas-antenna
https://top10perfect.com/wp-content/uploads/2015/07/B00RCOEL0C.jpg
https://images-na.ssl-images-amazon.com/images/I/51K2LYNmeRL._SL256_.jpg
https://i.ytimg.com/vi/CuY-D9fQG_s/hqdefault.jpg
https://i.ytimg.com/vi/Uas1t68hW8E/maxresdefault.jpg
 

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green circle is where the antenna is pointing; blue circle is possible alternative antenna location;
It looks like the signals avoid the trees better at the green circle.
So it sounds like I should ask the solar guys about using an old fashioned string inverter.
You will need to talk to the solar contractor when he does the site survey. I'm concerned about the panel shading from the trees at the SW and SE early and late in the day. IIRC, a series string of panels is more sensitive to shading. The large black rectangle looks like an ideal location for mid-day.
Would the panels themselves block the signal? If so, how high above the black panels would the antenna need to be? How far to the side of the yellow panels?
As long as the signals aren't blocked by the panels, you are OK. If the panels were horizontal, there might be a concern about a reflected signal causing interference to the direct signal, but the panels will be mounted at an angle. If the panels radiate interference, then the distance between the antenna and the panels is critical.
 

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The reason I did not mount the antenna on our roof is that we've got lightweight concrete tiles, and most roofers won't even go up on our roof for fear of breaking tiles. Plus it's steeper than I'm comfortable walking on.
As LastButNotLeast said, if the antenna can't be mounted on the roof, how can the panels be mounted on the roof?
 

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Discussion Starter · #13 ·
Thanks rabbit73. How did you get the antenna signals superimposed on the roof view? That's really helpful.

I did try mounting the antenna where the satellite dish used to be, at the far right (east) of the ridge where the main solar panels would be. I think the neighbor's roofline (to the south) blocked the signal though, because reception there was awful. They've got a metal roof. I don't think any of the other gables would be any better, since they would pass through multiple layers of roofing and/or solar panels (but they would be further away).

And yes, the trees on the SW and SE do block early morning and evening sun, but during peak solar hours, it's virtually shade free in the middle part of the south slope, especially up high. Unfortunately, that'w where our antenna is!
 

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Thanks rabbit73. How did you get the antenna signals superimposed on the roof view? That's really helpful.

I did try mounting the antenna where the satellite dish used to be, at the far right (east) of the ridge where the main solar panels would be. I think the neighbor's roofline (to the south) blocked the signal though, because reception there was awful. They've got a metal roof. I don't think any of the other gables would be any better, since they would pass through multiple layers of roofing and/or solar panels (but they would be further away).

And yes, the trees on the SW and SE do block early morning and evening sun, but during peak solar hours, it's virtually shade free in the middle part of the south slope, especially up high. Unfortunately, that'w where our antenna is!
Is it safe to assume that you've already installed a two speed or variable speed, super efficient pool pump and reduced the flow rate? That can make for huge savings in power usage. LED bulbs with CRI's over 90 can also provide quality light with large savings.

The question remains about putting the antenna on the roof. Is there a problem placing the antenna given that their has to be access for the solar install? Just have someone take off a few more roof tiles and you can get to the roof peak.
 

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How did you get the antenna signals superimposed on the roof view?
Easy to do here:
http://www.tvfool.com/index.php?option=com_wrapper&Itemid=90


Enter your location information, and when the map comes up enter antenna height, move cursor (drag and drop) to antenna location, and turn on green lines. The coordinates at the bottom of the map change as you move the cursor. You can generate a report by clicking on Make Radar Plot >> at upper right corner of map.


You have a choice (at lower right) of true vertical or bird's eye view, which shifts the cursor position.
 

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I get some interference from my neighbors solar panels into my amateur radio system. It shows up as a noisy carrier every 200 kHz all the way up to 50 MHz. It probably goes higher in frequency, but I don't have a receiver/antenna for anything above 50 MHz right now. I'm not sure what it would do to an ATSC signal.

Clearly, it's from a 200 kHz oscillator in the inverter system. Of course, the interference goes away at night.

Ron
 

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Discussion Starter · #17 ·
bigguyca- Great suggestion. Variable speed pump was the first thing we put in when we moved into the house. I couldn't believe how much of a difference that made. A whole house fan has also made a huge difference. (It almost always cools off nicely here at night.) And yes, we've got cfl's morphing into led lights throughout the house. I also blew in additional attic insulation. Our electric bill is quite low for the area. All the solar reps have commented on how low our usage/bill is. That's why we're on the fence about going solar.

I know I could have someone put the antenna on the roof. But if I ever needed to adjust it, then it'd be me going up where I don't feel comfortable. If we decide to go solar and the antenna is affected, we may have no choice. But interference could still be an issue.

Our antenna works great where it is. My main questions were:
1- how far away from line of sight do the panels need to be so that they don't physically block/interrupt the signal?
2- how much interference would we get from inverters, et. al.?

It sounds like we might be OK if we don't directly block the signal with a panel and if we use a string inverter rather than microinverters or optimizers.

Ron- I appreciate you sharing your experience. Would you happen to know what kind of inverter(s) your neighbor is using? Anyone else have any first hand experience with this?
 

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For what it is worth, we have had solar panels for several years. Didn't notice any reduction in tv signal after install. Our antenna is large but in our attic instead of on the roof. Inverters are huge and they two of them are in the garage. They are DIRECTLY under the antenna. To be fair, we pay for Dishnetwork, so we don't use the antenna that much, but certainly did monitor the signal after install.

I think you will be fine as far as the antenna. TV is VERY important to us, but at the same time, it isn't going to stop us from installing solar to charge our home and two EVs. We know there are micro-inverters that can be used that are installed on the roof where the panels are installed, but they are not the default ones used in our type of setup. Now, the roof type you have might be a bigger issue. Certainly the solar person that comes out to look things over should be to give you better answers than anyone here.
 

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I'm not a solar expert but my take is to use a single sine wave inverter. Micro inverters will spread interference over the roof top while a single inverter can be located away from the TV antenna. Square wave or staircase type inverters have a lot of harmonics that throw off interference as dr1394 described. The panels will reduce the TV signal if located over the antenna but shoud not do much if not in a direct line of sight to the source.
 

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Discussion Starter · #20 ·
actoprs1 and Babble- thanks so much for your posts. That's exactly the type of answers I was looking for. As for the solar people having better answers, with all due respect, they don't know much about OTA antennas.

Thanks to everyone's input. You've made my first venture into AVS Forum a very positive one.

FWIW (and for anyone reading this post looking for opinions on the topic)- the good people at the SolarPanelTalk forum also tend to prefer string inverters at this point. Microinverters have a history of failing (though it's possible the newer ones might be better), and optimizers seem to be somewhat of an unknown as of yet. Both present more points of possible failure. So if the panels can be placed in unshaded areas, they recommend a regular string inverter. Now to see if I can get quotes for a system with a string inverter...
 
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