On Mon, 30 Jul 2012 21:02:49 -0500, Char Jackson wrote:

Finally, if the antenna is capable, adjust the antenna's vertical aim.
Don't just eyeball that axis, since some antennas have built-in downtilt
that may not be obvious. I don't know if that applies to the Nanobridge.

The antenna is on a cantilevered mounting arm screwed into the outside
wall of the house under the roofline.
http://www4.picturepush.com/photo/a/...mg/8864332.jpg

Note: I tried four times to drill deeper holes but there is a solid steel
plate in that wall (apparently) that nothing can possibly dent. What is
it, I don't know! ???

While the mounting arm can't be tilted - the antenna bracket has many
degrees of tilt and rotation.

The problem is the tilt is hard to judge by eye so I did it by airOS as
shown in the screenshot below:
http://www3.picturepush.com/photo/a/...mg/8864421.png

BTW, I never understood transmit CCQ. Are these numbers OK?

On Tue, 31 Jul 2012 07:31:40 +0000 (UTC), "Vinny P."
wrote:

The antenna is on a cantilevered mounting arm screwed into the outside
wall of the house under the roofline.
http://www4.picturepush.com/photo/a/...mg/8864332.jpg

Looking at the data sheet, it appears that you're looking at about a
10 degree beamwidth:
http://www.ubnt.com/downloads/datasheets/nanobridgem/nbm_ds_web.pdf
Take a protractor and a piece of paper and draw 10 degree angle.
That's your alignment accuracy. Trying to bore sight aim that antenna
is not going to work. You'll have to rock it back and forth to find
the maximum signal point. From the screen shots you've posted, I
don't think your antenna is aimed at their AP.

Looks like you have it mounted vertically polarized. Is that what
RidgeWireless is using?

Note: I tried four times to drill deeper holes but there is a solid steel
plate in that wall (apparently) that nothing can possibly dent. What is
it, I don't know! ???

Probably a nail stopper protecting the area where Romex crossed over a
2x4.
http://www.strongtie.com/products/connectors/ns-nsp-pspnz.asp
Consider yourself lucky that you didn't continue as you would
eventually have drilled through a power line. Next time you drill,
use a stud finder to find the stud, but also use an AC voltage
detector to make sure you're not drilling into a power line.

Please remember that you have only one life to give for your
connectivity.

While the mounting arm can't be tilted - the antenna bracket has many
degrees of tilt and rotation.

The problem is the tilt is hard to judge by eye so I did it by airOS as
shown in the screenshot below:
http://www3.picturepush.com/photo/a/...mg/8864421.png

Ummm... you're on AirMax ISP firmware 5.3.5. Version 5.5 is out. Ask
your ISP before upgrading:
http://www.ubnt.com/download#NanoBridge:M2

BTW, I never understood transmit CCQ. Are these numbers OK?

Client Connection Quality. Basically, it's the ratio of how an ideal
radio would be expected to act, divided by what you're really seeing.
The Ubiquity definition is kinda vague. This is from Mikrotik and
hopefully should apply to Ubiquiti.

Client Connection Quality (CCQ) is a value in percent that shows
how effective the bandwidth is used regarding the theoretically
maximum available bandwidth. CCQ is weighted average of values
Tmin/Treal, that get calculated for every transmitted frame,
where Tmin is time it would take to transmit given frame at
highest rate with no retries and Treal is time it took to
transmit frame in real life (taking into account necessary
retries it took to transmit frame and transmit rate).




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Vinny P. wrote the following on 7/31/2012 3:31 AM (ET):
On Mon, 30 Jul 2012 21:02:49 -0500, Char Jackson wrote:

Finally, if the antenna is capable, adjust the antenna's vertical aim.
Don't just eyeball that axis, since some antennas have built-in downtilt
that may not be obvious. I don't know if that applies to the Nanobridge.

The antenna is on a cantilevered mounting arm screwed into the outside
wall of the house under the roofline.
http://www4.picturepush.com/photo/a/...mg/8864332.jpg

Note: I tried four times to drill deeper holes but there is a solid steel
plate in that wall (apparently) that nothing can possibly dent. What is
it, I don't know! ???

You probably hit a metal framing hanger (or framing metal hanger) in
that first area.


While the mounting arm can't be tilted - the antenna bracket has many
degrees of tilt and rotation.

The problem is the tilt is hard to judge by eye so I did it by airOS as
shown in the screenshot below:
http://www3.picturepush.com/photo/a/...mg/8864421.png

BTW, I never understood transmit CCQ. Are these numbers OK?




--
Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeros after @

On Tue, 31 Jul 2012 12:40:14 -0400, willshak wrote:

Note: I tried four times to drill deeper holes but there is a solid
steel plate in that wall (apparently) that nothing can possibly dent.
What is it, I don't know! ???

You probably hit a metal framing hanger (or framing metal hanger) in
that first area.

Whatever it is, it's big because the two bracket holes are a good four
inches apart, and I drilled four of them, about six or seven inches
apart, so the impenetrable object is (at a minimum) four inches by six
inches large.

On Tue, 31 Jul 2012 08:51:18 -0700, Jeff Liebermann wrote:

Looks like you have it mounted vertically polarized. Is that what
RidgeWireless is using?

Funny you should ask that.

I wasn't sure which way to mount it so I simply followed the instructions
that came with the radio.

I do know the WISP has both polarities because he's the one that told me
I was only using half the bandwidth with my Ubiquiti Airgrid - so gaining
the other polarity is the whole reason for me buying the nanobridge.

On Tue, 31 Jul 2012 08:51:18 -0700, Jeff Liebermann wrote:

Please remember that you have only one life to give for your
connectivity.

On Wed, 01 Aug 2012 18:58:32 -0700, miso wrote:

Your supposed to think WTF and give up, but the poster has dulled two
bits! I think he is hitting something else.

Four holes! Drilled about 4 inches apart up/down and about 6 or 7 inches
apart side-to-side.

I can't imagine what it is - but there is no way my drill bits were
making 'any' headway. I was on a ladder, so I couldn't use 'all' my
strength, but I've drilled enough to know that I was hitting hard steel.

I didn't even see any metal chips coming out, although they could have
been lost in the inch of stucco as I was pulling the bit out.

At the moment, I can only think that there is some kind of earthquake tie
of some sort since I'm very near the fault line.

BTW, would an antenna using a dish have significant lobes?

Looking at the Ubiquiti Nanobrdige M2-18 datasheet at:
http://dl.ubnt.com/nbm2_datasheet.pdf

The lobes don't look too bad:
http://www1.picturepush.com/photo/a/...mg/8883074.png

On Tue, 31 Jul 2012 08:51:18 -0700, Jeff Liebermann wrote:

Take a protractor and a piece of paper and draw 10 degree angle.
That's your alignment accuracy.

Hi Jeff,

Here's how my friend Simon explained it to me today ... so I hope to have
more data this weekend.

.... ... ... ... cut here ... ... ... ...

If you look at the antenna profile for the NanoBridge M2,
it shows you how much loss to expect if you are a few degrees off target.
If you are 15 degrees off-target, you lose about 7 dB.

15 degrees is a whole lot. The sun moves 15 degrees in an hour. Your thumb
and fist (like a hitch-hiker's signal) at arm's length is 15 degrees.

At 5 degrees off-target, you lose 2dB. That's three fingers at arm's
length. That is still quite a lot of miss. The entire mountain is 5
degrees across when looking at it from my house.

The sun and moon are each a half of a degree across. If you are off-
target by the apparent width of the moon, or even twice that, you won't
see a single dB of loss. The entire property where the antenna lies is
about a degree wide as viewed from my house.

In other words, aiming is not your problem.

We see random fluctuations in signal strength that dwarf anything like a
5 degree aiming error.

I have the tripod, and a bunch of brand-new NanoBridges. You can ride
along with me and we can set it up at different places along the road and
see what kind of signal and speeds we get, with and without the power
lines and towers in the way.

I'll be bringing it to Joe's house and Bill's house today or tomorrow,
and you can help set them up if you like, and we can get measurements
from those places as well.

On Sat, 4 Aug 2012 02:46:35 +0000 (UTC), Vinny P. wrote:
On Tue, 31 Jul 2012 08:51:18 -0700, Jeff Liebermann wrote:

Take a protractor and a piece of paper and draw 10 degree angle.
That's your alignment accuracy.

Hi Jeff,

Here's how my friend Simon explained it to me today ... so I hope to have
more data this weekend.

... ... ... ... cut here ... ... ... ...

If you look at the antenna profile for the NanoBridge M2,
it shows you how much loss to expect if you are a few degrees off target.
If you are 15 degrees off-target, you lose about 7 dB.

15 degrees is a whole lot. The sun moves 15 degrees in an hour. Your thumb
and fist (like a hitch-hiker's signal) at arm's length is 15 degrees.

At 5 degrees off-target, you lose 2dB. That's three fingers at arm's
length. That is still quite a lot of miss. The entire mountain is 5
degrees across when looking at it from my house.

The sun and moon are each a half of a degree across. If you are off-
target by the apparent width of the moon, or even twice that, you won't
see a single dB of loss. The entire property where the antenna lies is
about a degree wide as viewed from my house.

In other words, aiming is not your problem.

I've yet to see anyone question the pattern/lobes/nulls
of the _transmitter_.

Jonesy

On Sat, 4 Aug 2012 02:46:35 +0000 (UTC), "Vinny P."
wrote:

Here's how my friend Simon explained it to me today ... so I hope to have
more data this weekend.

It's a bit more complexicated than that. Just because you can see the
other end, doesn't mean that a 2.4GHz link will be reliable. Any
objects inside the Fresnel zone will cause problems. Reflections off
the ground will cause nulls and peaks. Moving objects (cars) close to
the path can cause fades. I use Radio-Mobile softwa
http://www.cplus.org/rmw/english1.html
to produce path profiles like this:
http://802.11junk.com/jeffl/coverage/K6BJ-to-KI6EH/K6BJ-to-KI6EH-Path-Profile-01.jpg
This one is at 420MHz and has some errors in the numbers, but gives a
tolerable idea of what can be done. All you need to do is supply some
numbers.

A simpler version is just the path loss.
http://wireless.navas.us/index.php?title=Wi-Fi#Link_Calculations
that simply calculates the fade margin, which directly translates to
reliability and uptime. I'm fairly sure you're close enough that
there are no path loss issues. I'm not so sure about obstructions
along the path.

If you look at the antenna profile for the NanoBridge M2,
it shows you how much loss to expect if you are a few degrees off target.
If you are 15 degrees off-target, you lose about 7 dB.

6dB loss is the same as cutting your range in half at the same signal
levels.

Another way to think about it is how much of your dish antenna can you
cover in order to produce a -6dB loss? Well, covering half will be
-3dB loss. Another half will be -6dB. So, how well does your dish
work with a dish only 1/4th the size?

In other words, aiming is not your problem.

Probably true. Something else is wrong which might be indicative of
defective equipment. The easy way to determine that is to compare
with a similar piece of hardware.

Did you ever settle on vertical or horizontal polarization?

We see random fluctuations in signal strength that dwarf anything like a
5 degree aiming error.

Random fluctuations as in fades and nulls is exactly what you get when
there are multiple reflections and objects in the Fresnel zone.

I have the tripod, and a bunch of brand-new NanoBridges. You can ride
along with me and we can set it up at different places along the road and
see what kind of signal and speeds we get, with and without the power
lines and towers in the way.

Great idea. Do it.

I'll be bringing it to Joe's house and Bill's house today or tomorrow,
and you can help set them up if you like, and we can get measurements
from those places as well.

Even better. Remove your Nanobridge and bring it along. Compare
signal levels.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 4 Aug 2012 13:06:16 GMT, Allodoxaphobia
wrote:

I've yet to see anyone question the pattern/lobes/nulls
of the _transmitter_.

Good point. That may be the problem. I run into it all too often.
The WISP decides to use a very high gain omnidirectional antenna.
Something like 15dBi with an 8 degree vertical beam width. If your
house is at the exact same altitude as the WISP antenna, everything
works just great. However, if the house is at the same distance, but
at a different altitude, the house will be outside the antenna pattern
and you'll get little or no signal as most of it will be going
overhead.

Even worse, end fed colinear antennas tend to have some uptilt in the
pattern. A 15dBi omni (which incidentally is about 8ft long), might
have ALL the RF above the horizon if nothing is done about the uptilt.
If the house is below this omni antenna, you'll get very little
signal.

Ease of downtilting is one reason why WISP's use panel or sector
antennas with patterns like:
http://802.11junk.com/jeffl/antennas/AMOS-7/index.html
120 degree horizontal beamwidth. 8 degree vertical. 14dBi gain.
Three of these antennas, wrapped around a pole, pointed 8 degrees
downward, put all of the signal on the ground in a wide pattern, with
very little being lost sending RF above the horizon. Note the
adjustable downtilt:
http://www.qsl.net/yu1aw/ANT_VHF/Amos_Ant/3InvAmosa7c.JPG

Hint: If it doesn't work on paper, it's not going to work when
installed.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

It isn't the signal strength as much as the waveform fidelity. If you
are off a bit, you get more reflections of the transmitted signal.

When I use a rather fat beamed antenna, I move it from side to side and
note where the signal begins to drop. then pick a spot in the middle.
This is something like direction finding, where null are easier to
detect than peaks. In this case you aren't using the null, but rather
you reach the edge of the main lobe and the signal falls off rapidly.