Hi all. I have a lhgxl 5g and a ldf with a 1 meter dish. After... Looking at it for a minute, there is simply no way to safely secure this dish at a location where it can see the node I'm trying to hit. I put up the lhgxl, but it really needs a bit more gain. In my brain bigger dish equals more gain, but on paper it seems that might not be the case with the ldf:
Lhgxl 5g says 28dBm and 27dBi of gain.
The ldf says 25dBm and with a 1 meter dish it can achieve up to 33dBi of gain. So with a .7 meter dish, it doesn't seem like I would see a substantial improvement.
Am I missing something?
Do i have any other options without moving up to a larger dish?
And actually, the weight of the 1 meter dish is the problem, not the size. If i could find one a bit lighter i might be able to make it work.
Thoughts?
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Those may be too heavy for your application.
Hi, Casey:
I have a link that may be useful as a comparison.
One end of my link seems very comparable to NS9RC-5G-PARKTOWER which I assume is a Rocket M5 (27 dBm) and a AM-5G16-120 (16 dBi).
If the Park Tower antenna is a AM-5G19-120, that would be another 3 dB in your favor.
My comparison is a SXTsq-5, 25 dBm and 16 dBi at 120 feet h.a.g.l.
I have -2 dBm compared to Park Tower.
Your path distance is 6.6 miles, mine is 6.2 miles.
With my -2 dBm, I say this is about 'even'.
Your end is either a LDF-5 (25 dBm) and a 1 meter dish (33 dBi) dish or a LHG-5HP-XL (28 dBm and 27 dBi).
My end is a LHG-5HP (28 dBm and 24.5 dBi) at 100 feet h.a.g.l. i.e. Line-Of-Sight.
-2.5 dBi compared to your LHG-HP5-XL.
My LHG-HP5 to the comparison node path gain is 68.5 dB (24.5dBi+28dBm+16dBi=68.5dB).
My SNR is 33 dB indicating a path loss of 35.5 dB. TxMbps=104.
My comparison node to my LHG-HP5 node path gain is 65.5 dB (16dBi_25dBm_24.5dBi=65.5dB).
My SNR is 32 dB indicating a path loss of 32.5 dB. TxMbps=78.
"Am I missing something?"
My LHG-HP5 is around 100 feet h.a.g.l.
I am missing your height above ground level for comparison.
Attaching path profiles for comparison.
1st image is your end at 25 feet h.a.g.l.
2nd image is my end at ~100 feet h.a.g.l.
I hope this helps,
Chuck
Hi, Casey:
I did some math. The LDF would have 3 dBi gain and equal dBm.
You did not mention using what other bandwidths nor other channels measured.
Did you do a 20 MHz bandwidth Wi-Fi scan from each end and then determine what channels might work better.
Chuck
Hi, Casey:
I think your path is over the utility pole on the right side of your image.
It appears that there may be some physical downtilt on the Park Tower antenna.
Both the Ubiquiti AM-5G[16,19]-120 antennas have built-in downtilt.
At 6.6 miles a 2 degree downtilt from 520 feet elevation would be optimized at 700 feet underground.
Chuck
I have tried to test different channels and bandwidth, but if there is a reference document or post somewhere on the proper procedure, I'd appreciate a link to that. I tried 5M and 10M and found that 10M was better because both dropped packets, but at 10M the packets that got through were larger / faster. I tried different channels and found that lower was better, but it was more of a spot check, not very scientific. I suspect on this hardware, they might be a little more optimized in the frequency ranges they were designed for.
You might be looking at the wrong antenna at park tower. It is tilted down just a degree or two. I wasn't aware of the physical down tilt of the antenna, so I did put in 2deg down, so it might be down a bit more than it needs to be.
I think you are almost spot on. See the additional images. I couldn't annotate from where I was posting (from my phone) yesterday. I've been using the tree in my neighbor’s yard as an alignment reference. I've also included an image of the summer view... not much hope there.
I was very optimistic when I initially ran the calculation (image below), but the reality is somewhat less optimistic.
Annotated Images:
http://nextcloud.caseydiers.com/index.php/s/PWKrbjSQxcT7fcR
I think all there is to put this dish up that is coming, enjoy it for the winter, and move on.
Thanks for the help in the calculations. I'm glad to hear there might be some gain increase.
"I did put in 2deg down, so it might be down a bit more than it needs to be."
Hi, Casey:
I did some math.
To drop down 490 feet in 6.6 miles would be a downtilt of 0.8 degrees.
That AM-5G19-120 has 2 degree downtilt built in.
From 520 feet elevation it would be optimized to ground at ~2.6 miles.
If you added extra downtilt, the antenna is optimized closer.
To optimize that antenna for you would be to set it for 1.2 degrees physical uptilt.
From viewing the data sheet, I am guessing there is ~5 dB loss toward your home node.
http://dl.ubnt.com/datasheets/airMAX_ac_Sector/airMAX_ac_Sector_Antennas_DS.pdf
3s,
Chuck