Yagi or parabolic grid in my situation?

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motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Yagi or parabolic grid in my situation?

Post by motoguy » Wed Sep 18, 2019 2:44 am

As mentioned in another thread, I'm in the process of putting together an LTE modem in hopes of replacing my crappy WISP service. I'm currently paying $100/mo for a 10mbps connection. I'm currently showing 4.8, and that's the best we've had this summer. It's likely to improve shortly, as the leaves fall off the trees. However, IIRC 8mbps or so is the best we've ever had. So, speeds that will "satisfy" me are likely quite low, relative two what I see from many of you here. I've asked my modem build questions in the other threads, so I'll ask antenna questions here!

I've found my local ATT antennas via Cellmapper.net. I've got 5 antennas that I've mapped at link.ui.com, to check signal possbilities. 3 of the towers show "link obstructed" by terrain, so I'm calling them dead. The other two show line of sight as far as earth, however there is heavy tree obstruction between my home and either tower. The "close" tower is 3.66 miles away, the "far" tower is 5.52 miles away. In addition, the far tower is almost exactly behind the near one. Heading on the near tower is 324.07, heading on the far one is 324.27, 2/10 of a degree separation. So, I don't see any way to separate them from each other, short of band locking (assuming I can see the further one).

We have Verizon phones, as ATT cell service at our house was horrible (good start, right?). I've been borrowing a family member's ATT phone to do some testing, and popping the sim in my Galaxy S8+ so I can use the Network Cell Info app. For my first tests, I just walked around the house gathering readings. They readings varied from my first floor (walk-out basement, essentially) to standing on the roof. The readings varied from -122db (downstairs) to -93 (standing at peak of the roof). While some of the low-mid 90's signal readings gave me hope, I've come to realize how bad those RSRQ readings are.
Screenshot_20190914-132321_Network Cell Info.jpg
Screenshot_20190914-132217_Network Cell Info.jpg
Screenshot_20190914-132201_Network Cell Info.jpg
Screenshot_20190914-131131_Network Cell Info.jpg
Screenshot_20190914-130759_Network Cell Info.jpg
Screenshot_20190914-130645_Network Cell Info.jpg
Screenshot_20190914-130605_Network Cell Info.jpg
Screenshot_20190914-133301_Network Cell Info.jpg

motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Re: Yagi or parabolic grid in my situation?

Post by motoguy » Wed Sep 18, 2019 2:51 am

Screenshot_20190914-131341_Network Cell Info.jpg
Screenshot_20190914-131319_Network Cell Info.jpg
Screenshot_20190914-131237_Network Cell Info.jpg
Screenshot_20190914-132057_Network Cell Info.jpg
Screenshot_20190914-132039_Network Cell Info.jpg
Since then, I've come to realize that while the -93db reading gives me hope, those RSRQ's are all horrible. I didn't do any d/l tests at that time.

motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Re: Yagi or parabolic grid in my situation?

Post by motoguy » Wed Sep 18, 2019 3:03 am

Later, having learned a bit more, I went out into the yard, and did some testing there. The dark screenshots below are from night time testing. I learned that I was seeing several bands (multiples on 2 and 5), and band 66 showed up at 1:30am. I also found my d/l speed tests at this time ranged from 7mbps (middle of house) to 17mbps (daughters' room, with exterior wall closest to towers), to 40+mbps (band 66, outside in the yard, 1:30am). I see an RSRQ of -6 on one of the band 5 readings, which gives me some hope. Again, these were all taken on a Galaxy S8+.
Screenshot_20190916-013511_Network Cell Info.jpg
Screenshot_20190916-013443_Network Cell Info.jpg
Screenshot_20190916-013433_Network Cell Info.jpg
Screenshot_20190916-013555_Network Cell Info.jpg
So, I do think there's some hope. Based on the ECI's and cellmapper.net, I was able to deduce that all these bands were on the same tower (same 1st 4 digits, only differed in last 4 digis). Searching the last 4 digits found the bands on the nearer tower on Cellmapper. I was also able to get the tower heights from Cellmapper. I've used the full tower heights here, understanding that the antennas may be mounted slightly lower. Here are the towers in question from Cellmapper:
towers.JPG
towers.JPG (92.1 KiB) Viewed 933 times
Here are the towers on link.ui.com. The circled green are the "visible" towers, the red circles are the 3 towers that are not visible to me, according to Airlink:
airlink towers.JPG
Here are the fresnel sims for the towers. I used the height of the antenna at the house as 20', figuring that would be the lowest elevation possible. First the "close" tower (green circle is house, red circle is tower):
fresnel1.JPG
And the far tower (green circle house, red circle tower):
Attachments
fresnel2.JPG

motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Re: Yagi or parabolic grid in my situation?

Post by motoguy » Wed Sep 18, 2019 3:29 am

Here are photos of the "close" antenna:
antenna close 1.JPG
antenna close 2.JPG
Here are photos of the "far" antenna:
antenna far 1.JPG
antenna far 2.JPG
And here are where those photos were taken from. Photo taken from the base of the arrow, in the direction indicated:
antennas photos direction.JPG
So, that gives an idea of the towers, the location relative to my house, distance, elevation (of earth), tree cover (thick), existing signal at location (per cell phone), and the fact that the paths run directly over the center of town, on top of many single-story buildings, and at least a few multi-story buildings. The Airlink site lists the "tilt" to the near tower as 1.07 degrees, tilt to the "far" tower as .91 degrees. Near tower is 300 ft tall, far tower is 452 ft tall. A whole lot of trees along that path.
trees.JPG
If we zoom in on the house, you'll notice that the gabled end is very nearly aligned with the path to the towers.
house.JPG

motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Re: Yagi or parabolic grid in my situation?

Post by motoguy » Wed Sep 18, 2019 3:36 am

My plan is to place antennas in the attic of the house, up near the peak of the roof, shooting through the gabled side of the house to the towers. The antennas could be placed right next to the insulation, making insulation, sheathing, house wrap, and vinyl siding all that stands between them and open air. I DO have a broadcast TV mast on the top of the house, but it only protrudes 8, maybe 10 feet above the roof peak. I'm not sure it could handle the weight from the yagis, and I'm pretty certain the mesh parabolas would kill it. In addition, cabling would be much better if I can run to the attic.

These are old photos from Zillow, about 5 years old. Gives an idea of the exiting TV mast, and the proposed location (as well as trees).
house2.JPG
house3.JPG
So...all that being said...I'm looking for input on antenna choices. Given the initial poor signal, the distance to the towers, and all the obstacles in between (trees, buildings in town, etc), I think I'm going to need a pair of high gain directionals. I'd like to go with the yagis, as they're about $40 each ($80/pair).

https://ltefix.com/shop/antennas/4g-lte ... l-antenna/

The wideband mesh parabolas are $200/pop, so $400 (plus whatever shipping is on these beasts) /pair.

https://www.signalboosters.com/bolton-t ... l-antenna/

I'd love to hear what thoughts or input you may have on the options (or if you think something else may be even better).

swwifty
Posts: 508
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Yagi or parabolic grid in my situation?

Post by swwifty » Sat Sep 21, 2019 3:27 pm

It looks like you've done a lot of homework on this, which is good. Based on what you share you should easily have a great signal strength with some good antennas. Cell phones (even a newer Samsung S8) have really crappy antennas compared to real external antennas.

If you are going to go through all the effort of running a cabling and antennas into that attic, I would just take it a step further and put the antennas on your TV mast. This will help even more with signal strength. The yagi (they are actually log periodic type antennas, not sure why it says yagi) option antennas are very light. I have them on my roof and have used them for a while now, and they work quite well. If you are worried about space, then I'd look at the proxicast cross polarized mimo antenna. It combines two antennas into one physical enclosure.

Let me know if you have any more questions, happy to help where I can.

motoguy
Posts: 19
Joined: Tue Sep 17, 2019 10:09 am

Re: Yagi or parabolic grid in my situation?

Post by motoguy » Mon Sep 23, 2019 2:17 pm

A big part of my issue with putting antennas on the existing mount is running wiring into the house. The current wires off those antenna just run through the shingles on top of the house...they kind of lifted a shingle up, and "tucked" the wires under there. I'm not a fan of that...at all. As a matter of fact, I'll be getting up there in the attic and looking for signs of leakage. I suspect I'll also be toting a can of the tar roof sealant up there, and smearing it around that roof puncture.

I'm largely wanting to put the antenna in the attic 1) to avoid running (2) thick LMR400 through the roof/shingles, and 2) get the Pi/modem near the antenna, possibly doing away with LMR altogether.

So, that being said...what about mounting the pi/modem in a weatherproof box (like your external enclosure), and mounting that on the mast, below the antennas? At that point, I'm just running some outdoor-rated CAT5 from the 1st floor up to the roof-mounted box. That CAT5 should snake through the existing roof puncture, without having to increase the hole size.

Seems like that gives me the best of everything...high outdoor antenna mount, no runs of antenna cable (loss), no thick-diameter antenna cable (x2) through the roof, etc. The main concerns at this point would be Pi/modem cooling, exposed to the sun a few feet above the (heat absorbing) shingles.

swwifty
Posts: 508
Joined: Thu Aug 30, 2018 8:21 pm
Location: NE GA Mountains

Re: Yagi or parabolic grid in my situation?

Post by swwifty » Mon Sep 23, 2019 7:53 pm

I would do just that. Mount the PI on the antenna mast in a nema enclosure, if there is no eave or wall to mount the nema enclosure on the outside of the house. Then like you said the ethernet cable is all that is required to go inside.

Heat will probably be an issue, but you can put some fans on the PI. I have heard of people with similar setups outdoors in Texas that had no issues. I've never seen my modem temps go above 155F, but granted my nema enclosure is under an eave, but it still easily gets 90+ degrees here.

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AntennaRaul
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Re: Yagi or parabolic grid in my situation?

Post by AntennaRaul » Tue Dec 10, 2019 6:00 pm

Great piece of work putting together all that information. I didnt have time to read 100% of it but Swiffty is right. Best solution is the radio device in a box a few feet from the antenna/s. I followed down the thread because I saw "Yagi" and thats no good because thats a narrow band antenna. Im sure you mean the triangular white plastic radomes which are actually log-periodic 700-2700. If you could lock your device on the 700 Mhz LTE band then a 700 Mhz Yagi would be great. But since carriers can be changing bands thats a bad choice.. For a 3-4 mile path the 12dBi log periodic is fine. For longer then the mesh grid you found is better. Putting any cell antennas in the attic is a no-no. Theres just too much attenuation through all those materials. This is an old post I found so maybe by now you are all set.

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