Here's my opinion and that's all it is. Recently found a local guy selling TMobile plans and a MoVi 4500 sim7. He locks the MoFi to band 71 because like you, I'm 11 miles from the TMobile B71 tower. Now I live in the foothills of the Blue Ridge, but according to some info I found
https://www.heywhatsthat.com/?view=F1HIW37M I have LOS to the tower, not counting for the trees, I cannot see the tower from my house. I don't know what your actual terrain is like, desert, woods? I tried the '10dB' gain LPDA and compared it to a small Moxon antenna. You can look up Moxon antenna, there's plenty of data on it. The antenna you will have to make but it's dead simple with some #10 solid copper house wiring and 3 overlapping shrink tubing to hold the director on the driven element. I made a bunch on female N connectors and a few on BNC connectors. They all work the same. But I've found the Moxon despite it's relatively low gain, works better than the LPDA and even better than a Bolton 'parabolic' I tried. I use the quotes because It's my belief that these numbers and names are somewhat hyped. Any wide freq band antenna is going to be a compromise unless it's really huge, like a rhombic or large 10-14 turn helix. Also, depending on how high you can get your antenna, at normal heights, like your deck or even roof, the signal is only going to be so strong and the S/N ratio so much. I don't care how many dB gain antenna you have, you are not going to get it any better than what exists there right now, unless you get it up really high.
So, it's my belief, that in some circumstances these high gain antennas will work, in situations where your are really LOS and no obstructions, including trees or have a tall tower. The Moxon has a very wide beamwidth, 3dB down at about 90° and the bandwidth is quite good from 590 to 710 with the SWR flat across that band below 1.5:1. So perhaps it's actually receiving fringed signals better than the narrow beamwidth antennas.
Any of the LPDA or 'parabolic' antennas I've swept for SWR have deep low SWR and high SWR, like 3:1 or worse. Like I say, they're a compromise antenna for bandwidth. They can be made better, but will be very large.
I made a 9 el wideband yagi that also covered the 600-700 B71 frequency pretty good, but had swr peaks and valleys, but only in the 2:1 SWR and less range. Well, that 9 el still does not work as good as the Moxon and it supposedly has about 10dB theoretical gain over the Moxon.
That terrain site I linked is free but a bit of a bear to figure out. If you're competent, you should be able to figure out how to make it work for your location and the tower if you know the lat-lon of each.
Beware too, a lot of these LPDA antennas do not support the 600-700 B71, most start at 700 and up. The little paddle antennas that come with the MoFi also start their good SWR at 700MHz and up. I actually measured it.
I get anywhere form -100 to -119 dBm main signal strength, mostly it hangs around in the -102 range and RSRQ anywhere from -10 to -15 or worse. But I get download speeds ranging from 5 to nearly 20Mbps. The LPDA and Bolton I would get -106 at best. This morning it's in the -115 range at -12RSRQ but I'm still getting nearly 10Mbps down.
I'd like to try a panel antenna, but again they're a compromise for wide bandwidth and probably are about unity gain at B71. Good luck, all you can do is try or put up a tall tower.
I remain to be convinced of this MIMO stuff, plus how do you know the tower you're accessing uses it? It may work if you have a good signal.
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