Verizon- Yagi vs Grid

dsm382 · Posted: Fri Nov 21, 2008 6:45 pm Post subject: Verizon- Yagi vs Grid

Last week I had the Plastic dual band Yagi and was able to get a -84 holding it in my hand setting on my roof.
did some more reading and orderded a paroblic 900mhz grid, went up on roof togight and got the following results, hummm maybe i sent the yagi back too soon????

guess i need to sell house and move.. Sad

I give up.

Okay only worked 11 hrs today but started early and got home before dark.
I mounted grid on pipe on gutter board on upper part of house. Dragged laptop up there and got started.

After all the other testing I have a ‘good’ idea where the tower is.
Homed in on -95 held good and started ‘fine’ tuning.

Long story short, 95 seemed to be the ‘best’ I could keep for any length of time.

BUT. I did see -80 more than a few times, BUT in the same few mins, without moving grid, I also saw 100+ and RED. Meaning I did not go to National Access but just plain red = no signal and 0.

Then bounce right back and as a matter of fact as I write this I am seeing the same thing, red,93,red,93,93,93,93,93,93,93,red,93,93,93,93,93, meaning it stays green and 93 for a while and bam goes away.
I am sure I need to keep ‘tuning’ but DAMN.

Holding the plastic Yagi last week I was able to keep 84,,, don’t understand.

Cept that the yagi has a wider span, right?

And the grid is tighter to be able to home in on a better signal, right?

So I have the cable tossed down and through the window to see how it does this evening, got too cold to be outside going to 17 degs tonight.

Sunday going to be 40, T-shirt weather.

Will go back up and go to the very peak of the roof, and hold the grid and see if I can get any better.

Where I am planning on mounting I could go higher, but not much right now I would say I am 25’ off the ground, and I am sure the tower is lower than I am.
This is frustrating.

I am in automatic mode not Forced HDR. I am NOT bouncing between national and broad band, just loosing broadband.

Oh and when I was done testing and unplugged the gird, I went right up to 100 and 111, so yes the grid does help . just have to find the ‘sweet’ spot…

Just took some speeds -93 and -94 for the most part

Download Speed: 514 kbps (64.3 KB/sec transfer rate)
Upload Speed: 387 kbps (48.4 KB/sec transfer rate)

Download Speed: 513 kbps (64.1 KB/sec transfer rate)
Upload Speed: 63 kbps (7.9 KB/sec transfer rate)

Download Speed: 445 kbps (55.6 KB/sec transfer rate)
Upload Speed: 126 kbps (15.8 KB/sec transfer rate)

Download Speed: 450 kbps (56.3 KB/sec transfer rate)
Upload Speed: 388 kbps (48.5 KB/sec transfer rate)

http://www.speedtest.net/result/360067353.png

http://www.speedtest.net/result/360076329.png

http://www.speedtest.net/result/360076643.png

http://www.speedtest.net/result/360077367.png

most consistent speeds I have ever gotten. But well I guess I expected better..

well I thought I would ‘dial’ up and run a speed test for comparing but after waiting 10 mins for the test to start, which it did not, I gave up….
Guess these speeds are that bad.

But they should/could be better.

so since the yagi got a 84 and i have seen 80 more then once and i 'think' i saw a 7 something might have been 79 don't know. well one would think i should be able to get a mid 80?

anyone got anything to add? (other then sell house, move closer to city?)

n6gn · Posted: Sat Nov 22, 2008 12:12 am Post subject:

To follow up publically on some privat e mail about this so that others will also see it:

The following picture is exactly WRONG for EVDO:
http://www.hyperlinktech.com/productfamily.aspx?id=295

Getting this wrong will make so much difference that it may amaze you.This could cost you as much as 20 dB!

The vertical ribs in the grid need to be parallel to the feed and the whole works needs to be vertical. Mounted as shown in the above picture the thing is horizontally polarized. The EVDO tower is VERTICALLY polarized. Turn it 90 degrees.
n6gn

widgetman101 · EVDO Junkie Joined: 02 Apr 2008 Posts: 210

widgetman101 · EVDO Junkie Joined: 02 Apr 2008 Posts: 210

Also I forgot to mention did he buy the correct frequency? Was your Yagi a dual band one? Because you might have bought the wrong frequency Grid.

Did you buy a 2.4Ghz or 900Mhz one? Is the horn setup in the proper orientation also?

dsm382 · Posted: Sat Nov 22, 2008 5:41 am Post subject:

widge man YES my grid is mounted like yours but the 'horn' is NOT veritcal to the ribs. the 'horn' is horz.

and if i understand N9g correct in his PM, the Horn needs to be vertical.

yes i get higher DLUL speeds 100yards up the road with the mag mount antenna on my Van, and closer i get to tower (only 2miles away) i get much better DLUL speeds and have gotten -70 at one point.

yours i pretty high, i had a 6' pipe yesterday but did not want to mount due to support.
using 1 1/4" rigid gavl, pretty strong.
might go to a 6' or 5' peice tommorrow to get higher, not sure how much that would help due to the trees ( 100 yrds away i am clear) and not sure but pretty sure tower is below me.

thanks,
will update tonight after swtiching the horn, if i am correct that i am wrong Very Happy

dsm382 · Posted: Sat Nov 22, 2008 5:44 am Post subject:

rigght now i am inside a block school working with just USB720 and

-89

Download Speed: 716 kbps (89.5 KB/sec transfer rate)
Upload Speed: 429 kbps (53.6 KB/sec transfer rate)

Download Speed: 804 kbps (100.5 KB/sec transfer rate)
Upload Speed: 400 kbps (50 KB/sec transfer rate)

Download Speed: 804 kbps (100.5 KB/sec transfer rate)
Upload Speed: 432 kbps (54 KB/sec transfer rate)

not really 'in' the city today but on the outskirts of town, not sure where the tower is here. course i know i can get into the 70's outside, so if i can get to the 80's at home i could/would be happy....

oh and right now i am streaming a live radio show, so that could be better then i thought if i can get it to work at home.

dsm382 · Posted: Sat Nov 22, 2008 5:47 am Post subject:

also forgot to add

purchased the 900mhz verzion finally confirmed, if they can be trusted from what i have seen.

and YES even though the RSSI is only -94/-95 it does not drop to National access like the plastic yagi.

the yagi i had to force to hdr to keep it out of the national access...
so the grid is better for sure so far.

SteveInArk · Posted: Sat Nov 22, 2008 8:47 am Post subject:

Obviously you will try to get the grid parabolic antenna higher. That is important. The wind load of that antenna is extremely small, so you can use some pretty small pipe to get it up there cheaply. The cheapest ideal would be a 30 pushup mast, cheaper than that is 2-3 section of small TV mast, lightly guided at the top. Most important thing don't even get near power line to house, for safety reasons.

What is distance from the practical, final antenna height you expect, to your equipment in the house... meaning how much coax will you be using?

The quality of your coax is "critical". Good quality RG-6 cable (and you may not have that), has 5 db loss at 900mhz. You can get that down to 1-2 db loss fairly easy with better cables. But that cost more and takes some expertise in installing/obtaining differenct connectors or jumper cables to match up everything. And bulkier. However, if you have the expertise or a friend that does, that will help.

Past that, you get into amplified repeaters, etc... and the expense really jumps. Sad

_________________
Steve

SteveInArk · Posted: Sat Nov 22, 2008 9:24 am Post subject:

dsm... saw on other thread that you have 50' of LMR400 coax... that will be great for you... coax should not be an issue, when you get the correct connectors (that is important). Very Happy

_________________
Steve

n6gn · Posted: Sat Nov 22, 2008 10:32 am Post subject:

widgetman's picture is correct as far as I can see. I say 'as far as I can see" as I'm only about 90% sure that I can make out the feed running vertically just like the shorter, inner ribs in the grid.

This is proper assembly of the dish and a vertically polarized arrangement which is what is needed for all of the mobile carriers (as far as I know).

WiFi or other applications might use horizontal polarization for which EVERYTHING would be rotated 90 degrees. The URL I posted above was that type of installation.
If you don't orient the feed forrectly with respect to the inner ribs the antenna will NOT perform well. Similarly if you don't orient the whole assembly correctly you will be operating "cross-polarized" for which there may be as much as a 20 dB penalty. It really matters!
n6gn

n6gn · Posted: Sat Nov 22, 2008 11:07 am Post subject:

MIne looks like this:

and delivers -59 dBm from a ~1 mile cell site during the winter when the foliage is reduced.
n6gn

dsm382 · Posted: Sun Nov 23, 2008 3:28 am Post subject:

well crap. i did install it correctly. when i got home i looked up and crap.
oh well.
guess i shall try and raise it higher.

this is a temporary mounting till i get it 'right' then will set up a permenanet one.

i'm guessing maybe i'm not high enough off the roof, and it's causing interfearcne?

widgetman101 · EVDO Junkie Joined: 02 Apr 2008 Posts: 210

Yes you definitely have it setup correctly. In the picture it looks like its tilted at an angle though. Did you put it at an angle on purpose? Maybe its just the picture though. Make sure its level with the ground and not tilted at an angle.

If you know where the towers are at you want to have your antenna setup in the place with the clearest site in that direction.

And LOL at your temp setup. Mine's been setup like my picture for 9 months and it was just a temp setup too lol. Granted its freaking cold out now but I may setup my actual tower this spring.

If you have a volunteer and a laptop take the whole cable outside with you. Remove the grid mount. IE were you have it attached to the board. Have someone take the poll and walk around your roof experimenting.

When I setup a repeater setup for a co worker that's what I did. We checked readings all over. He rotated and steadied the antenna and I took readings with my laptop. Much easier than going in and out making small changes. Just be sure to leave it at each test location for a few minutes so it has a chance to pick up any type of signal. Sometimes the signal doesn't appear instantly.

dsm382 · Posted: Sun Nov 23, 2008 6:35 am Post subject:

yea, well if you see that little black vent behind it THAT is where i had the laptop up on the roof with me.... Very Happy

when it warms up i shall intall a taller pole and restet.

right now i am streaming live radio so we are getting there.
and with only -95

yes it is tilted, my thought was to get it up higher.

i have read that it has to be level

i will raise it higher and level it when weather allows....

n6gn · Posted: Sun Nov 23, 2008 10:30 am Post subject: