How to debug a reluctant WISP AP association (before I blame theWISP)

What data can I collect from my Bullet M2 radio to show to my new Santa
Cruz Mountain WISP provider that my radio refuses to "associate" with the
access point for hours upon hours after a (very) minor change in the
radio settings?

HISTORY:
- I'm was trying to learn about power & distance radio setup.
- Yesterday, I started playing with the ACK distance setting.
- I've read it should be set to 120% of the actual distance to the AP.
- Google map calculators put me at 7,500 feet from the WISP antenna:
http://www.daftlogic.com/projects-go...calculator.htm
- Google KML calculators put me at line of sight to the WISP antenna:
http://picturepush.com/public/7525357
- The working starting default ACK was 0.4 miles as shown here:
http://picturepush.com/public/7525349
- The moment I changed the ACK last night to (the correct) 1.8 miles, I
lost my connection.

The lack-of-association stayed gone for hours, even though I could easily
SEE I had -65dBm signal strength. It would not associate. I went to bed
and by the time I woke up, the access point had associated with my radio
(with me doing nothing in between except giving it time).

This is a screenshot of the results:
http://picturepush.com/public/7525351

So, today I tried changing the ACK again, this time to the maximum (14.5
miles). Again, immediately I lost the association with the WISP AP even
though I could see I had good signal strength of about -64dBm.

Again, this association lasted for hours with me doing nothing but a
zillion reboots, scans, switches to other access points (none of which I
could connect to because they weren't mine), etc.

Finally, all of a sudden, the kids yelled "The Internet is working
again", and there it was. Here is a screenshot of the current results:
http://picturepush.com/public/7525352

I really don't understand HOW TO DEBUG this problem.

I recently switched to a new WISP provider here in the Santa Cruz
Mountains and I don't want to call him yet until I gather enough data
from the radio about what is happening. I don't really think the ACK is
the problem since it shouldn't have that major of an effect (both ways).

Plus, I didn't document it as my memory may be foggy on this but I now
remember had lost the association for hours once or twice before when I
made a minor tweak to the settings.

So, something is very wrong - but then it's all right (on its own).

QUESTION:
What data can I gather to provide to the WISP to indicate whether the
problem is in his equipment or mine?

EQUIPMENT: 19 dBi planar antenna + 28dBm (630mW) Bullet M2 radio

On Thu, 09 Feb 2012 02:53:52 +0000, Chuck Banshee wrote:
> QUESTION:
> What data can I gather to provide to the WISP to indicate whether the
> reluctance to associate is in his equipment or mine?
>
> EQUIPMENT: 19 dBi planar antenna + 28dBm (630mW) Bullet M2 radio

I forgot to mention the WISP & laptop equipment involved so I'll list it
here:
- WISP AP = Compex Systems WLM54AGP23, 23dBm TX, 802.11b -92 dBm@1Mbps RX
- My radio = 19dBi planar & 28dBm (630mw) radio 1.5 miles away LOS
- My laptop = Lenovo X61 Ubuntu, internal -6dBm antenna & 15dBm (30mW)
radio with sensitivity of -90dBm@6Mbps

Given this equipment, what tests can I run to figure out WHY a minor
change in the radio's AirOS settings causes a disassociation from the
access point - which lasts for hours - and finally corrects itself over
time?

On 2/8/2012 6:53 PM, Chuck Banshee wrote:
> What data can I collect from my Bullet M2 radio to show to my new Santa
> Cruz Mountain WISP provider that my radio refuses to "associate" with the
> access point for hours upon hours after a (very) minor change in the
> radio settings?
>
> HISTORY:
> - I'm was trying to learn about power& distance radio setup.
> - Yesterday, I started playing with the ACK distance setting.
> - I've read it should be set to 120% of the actual distance to the AP.
> - Google map calculators put me at 7,500 feet from the WISP antenna:
> http://www.daftlogic.com/projects-go...calculator.htm
> - Google KML calculators put me at line of sight to the WISP antenna:
> http://picturepush.com/public/7525357
> - The working starting default ACK was 0.4 miles as shown here:
> http://picturepush.com/public/7525349
> - The moment I changed the ACK last night to (the correct) 1.8 miles, I
> lost my connection.
>
> The lack-of-association stayed gone for hours, even though I could easily
> SEE I had -65dBm signal strength. It would not associate. I went to bed
> and by the time I woke up, the access point had associated with my radio
> (with me doing nothing in between except giving it time).
>
> This is a screenshot of the results:
> http://picturepush.com/public/7525351
>
> So, today I tried changing the ACK again, this time to the maximum (14.5
> miles). Again, immediately I lost the association with the WISP AP even
> though I could see I had good signal strength of about -64dBm.
>
> Again, this association lasted for hours with me doing nothing but a
> zillion reboots, scans, switches to other access points (none of which I
> could connect to because they weren't mine), etc.
>
> Finally, all of a sudden, the kids yelled "The Internet is working
> again", and there it was. Here is a screenshot of the current results:
> http://picturepush.com/public/7525352
>
> I really don't understand HOW TO DEBUG this problem.
>
> I recently switched to a new WISP provider here in the Santa Cruz
> Mountains and I don't want to call him yet until I gather enough data
> from the radio about what is happening. I don't really think the ACK is
> the problem since it shouldn't have that major of an effect (both ways).
>
> Plus, I didn't document it as my memory may be foggy on this but I now
> remember had lost the association for hours once or twice before when I
> made a minor tweak to the settings.
>
> So, something is very wrong - but then it's all right (on its own).
>
> QUESTION:
> What data can I gather to provide to the WISP to indicate whether the
> problem is in his equipment or mine?
>
> EQUIPMENT: 19 dBi planar antenna + 28dBm (630mW) Bullet M2 radio

How do you know there is no interference?

Incidentally, with radio, you often hack a bit with the antenna and then
make the theory match the results. For instance, tilt the antenna back a
bit, or twist it a little off vertical. You can't relocate the antenna
unfortunately, but sometimes moving it a bit makes a difference.

I'm not sure why the Dell matters. You really should only run the wifi
link to the WISP and get that as good as possible before you add a local
WAP.

On Wed, 08 Feb 2012 20:09:22 -0800, miso wrote:
> How do you know there is no interference?

I have no idea if there is interference.
I don't even know HOW to test for interference.
All I do know is:
a) The signal strength is around -66dBm with noise around 88dBm
b) The transmit CCQs are in the 100% to about 95% range (usually)
c) The connection is good while it's connected
d) But the split second I change anything, it loses its association for
hours on end.

> hack a bit with the antenna and then make the theory match
I did align by signal strength by twisting it and changing the angle to
vertical.

Are you saying I should align by some other metric than the best signal
strength?

> I'm not sure why the Dell matters.

The laptop only matters if someone suggests a Linux tool to debug why the
radio won't associate with the WISP AP for hours upon changing any
setting in the radio itself.

On 2/8/2012 9:19 PM, Chuck Banshee wrote:
> On Wed, 08 Feb 2012 20:09:22 -0800, miso wrote:
>> How do you know there is no interference?
>
> I have no idea if there is interference.
> I don't even know HOW to test for interference.
> All I do know is:
> a) The signal strength is around -66dBm with noise around 88dBm
> b) The transmit CCQs are in the 100% to about 95% range (usually)
> c) The connection is good while it's connected
> d) But the split second I change anything, it loses its association for
> hours on end.
>
>> hack a bit with the antenna and then make the theory match
> I did align by signal strength by twisting it and changing the angle to
> vertical.
>
> Are you saying I should align by some other metric than the best signal
> strength?
>
>> I'm not sure why the Dell matters.
>
> The laptop only matters if someone suggests a Linux tool to debug why the
> radio won't associate with the WISP AP for hours upon changing any
> setting in the radio itself.
If you have linux, you could run Kismet to site scan, but not all radios
are "promiscuous." Even then, it is possible someone is running wireless
video, which Kismet can't detect. But Kismet is a start.

I'm saying move the antenna in whatever way works. If the WISP is at a
higher altitude, you probably want to angle the antenna back a little.
Or if it is lower, you aim down. Generally quality of signal is what you
want rather than signal strength. You can try tilting the antenna a bit
to see if being slightly off of vertical improves things. My point is it
is OK to hack a little.

Some high gain antennas have significant lobes. It isn't a simple matter
of more is more. For the point to point systems I set up, I use the
L-com PA24-16, specifically because it is a combination of high gain and
has very modest lobes.

> http://www.streakwave.com/mmSWAVE1/V...a_Sheet-v2.pdf

If you look at the display, the lobes of the 19dbI antenna are down
about 12 dB. The scale makes it look crappier than reality. But I
preferred to use the 16dbi version, while has lobes that are further
down and much more to the side.

You certainly have enough signal strength, but perhaps the quality of
the signal isn't very good.

Doesn't the WISP provide the antenna as part of the package? This might
be a case to make it someone else's problem, especially if it is on
their dime.

You can view the L-com catalog and see how gain and lobes are not
exactly correlated. For instance, those dish type antennas have very
small lobes, but the cost is high.

> http://www.l-com.com/category.aspx?ID=2073

Evey time I mention L-com that troll comes out of the woodwork to diss
them. The same with Alfa. Perhaps a pre-emptive diss will keep the
poster out. ;-)

Do you know if you have line of sight? Are there tree in the way? I've
done 7 mile links, so 7500ft isn't much of a challenge. Actually, if
your antenna has lobes, you might not be aimed correctly. That is, you
could be receiving off a lobe. If you are aiming with a compass, is it a
really compass or a freaking iphone/GPS. I'm totally convinced the
Cammenga compass is the only way to aim an antenna if you can't see the
transmitter. I've set up satellites with a cammenga, and sat dishes are
very directional.

http://www.cammenga.com/

Speaking of interference, the site survey isn't a 5 minute sniffer job.
Maybe your interfering party turns their system on and off.

> you could run Kismet to site scan,
> but not all radios are "promiscuous.

I'm googling for a better external USB radio for the Linux laptop.

Apparently you need a few things in the radio for good packet sniffing:
1. The radio should come with Linux drivers
2. The radio must support "monitor mode"
3. The radio must be promiscuous (that may be the same as monitor mode)
4. The radio must support "packet injection"

So far, by googling, I've found only one radio that does this:
Alfa Network AWUS036H ($28), TX=20dBm (100mW), RX=-91dBm@11Mbps802.11b
Antenna=2dBi omni,
Power = USB, Linux drivers = yes,
Monitor mode = yes, Packet injection = yes, Promiscuous=?

But if I'm going to buy anything, I prefer a stronger gain such as this 1
Watt USB radio (but I don't know if it is promiscuous):
Alfa Network Tube-U(N), TX = 30dBm (1 Watt), RX = -95dBm@ 1Mbps802.11b
Antenna Connector=N-Type Male (so you can add any antenna you like
Power = USB, Linux drivers = yes,
Monitor mode = ?, Packet injection = ?, Promiscuous=?

> quality of signal is what you want rather than signal strength.

Interesting. I was going for pure decibels. Is transmit CCQ the quality
metric I try to maximize? If not, I don't know what other 'quality'
metric to aim for that I can measure at the radio.


> I use the L-com PA24-16

I'm currently using the 19dBi Laird Technologies PA24-19 from Streakwave
in San Jose, installed on the antenna mast along with the 28dBm (630mW)
Bullet M2 radio so I'm familiar with that suggested brand (and I like
them).

In addition, if I buy the 1 Watt Alfa Network bullet USB radio, I'll need
an additional external antenna. The antenna consumes 100 Watts though, so
I'm not sure if that can be handled by the USB port (because 500mA USB x
5 volt USB is only 2.5 Watts)

> the lobes of the 19dbI antenna are down about 12 dB.
> I preferred to use the 16dbi version, while has lobes that are further
> down and much more to the side.

Of the three Laird antennas on that datasheet, I agree, the lobes of the
16 dBi version are cleanest (by far)!

One potential issue with the 16 dBi antenna is that, of the three, it's
the only one that doesn't support "surface mounting". What is "surface
mounting" anyway? They all support 1" to 2" pole mounting, which I'm
familiar with. But what is surface mount anyway?

> Doesn't the WISP provide the antenna as part of the package?

Long story. I prefer to use my own equipment. The WISP charges $400 to
install his equipment. I talked him out of that (he was reluctant to
agree but I told him I prefer better equipment and better installation).
In the end, that's what I got:
a) I put the antenna where I wanted it - not where he was gonna put it
b) I chose a 630mW (28dBm) radio - he was gonna use one inside the antenna
c) I chose a 19 dBi antenna - his was gonna be an all-in-one
d) I didn't drill any holes to get into the house - he would have
e) I buried the cat5e cable - he would have strung it in the air
f) I put the wall plate in the middle of the house - his would have been
on an outside wall
etc.

In the end, it cost me as much (or more) than it would have for him to do
the work - but I have a better installation - and I can control the radio
and the settings.

> Do you know if you have line of sight? Are there tree in the way?

I've never visually 'seen' the WISP antenna but the WISP came to my house
and said there was line of sight and he gave me the coordinates to his
antenna (which I posted in the picture in the first post).

> If you are aiming with a compass, is it a real compass

I'm aiming by signal strength, as read by the radio screwed onto the back
of the antenna.

> The Cammenga compass is the only way to aim an antenna
> http://www.cammenga.com
I see. Very nice. Rugged looking. With good directional aids.

> Speaking of interference, the site survey isn't a 5 minute sniffer job.
> Maybe your interfering party turns their system on and off.

That kind of stuff is EXACTLY why I want to find good sniffer software
that works on the Linux laptop (along with a good external antenna & USB
radio for that laptop)!

On Thu, 9 Feb 2012 16:26:32 +0000 (UTC), Chuck Banshee
<chuckbanshee@private.com> wrote:

>> If you are aiming with a compass, is it a real compass
>
>I'm aiming by signal strength, as read by the radio screwed onto the back
>of the antenna.
>
>> The Cammenga compass is the only way to aim an antenna
>> http://www.cammenga.com

>I see. Very nice. Rugged looking. With good directional aids.

I never use a compass. Too many errors when working with high gain,
narrow beamwidth antennas, which need better accuracy.

Instead, I use a road map, some pins, and a piece of plywood. Locate
yourself on the map. Insert a pin. Locate a landmark (e.g. mountain
top) that you can see. Insert a 2nd pin. Sight between the two pins
and rotate the map. Now, the map and the planet are identically
oriented. Find your target on the map, insert a 3rd pin, sigh between
your location and the target, and point your antenna the same way. I
can do about +/- 1 degree this way (if I'm careful or use a
theodolite). You can't even get close to that with a compass.

Also, don't aim by signal strength unless you have perfect line of
sight. If you happen to pick a reflection, rather than the incident
signal, it's not going to be stable. When the wind blows, the signal
will change. Best to aim the antenna geographically, tolerate a
somewhat lower signal level, and not have it change later.


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

Chuck Banshee (for it is he) wrote:

> Apparently you need a few things in the radio for good packet sniffing:

> 4. The radio must support "packet injection"

Not sure that's entirely necessary - I think that's more useful for when
you're trying to crack someone's encryption by feeding it the "right" sort
of packets to make the AP do the wrong thing!

> So far, by googling, I've found only one radio that does this:
> Alfa Network AWUS036H ($28), TX=20dBm (100mW), RX=-91dBm@11Mbps802.11b
> Antenna=2dBi omni,
> Power = USB, Linux drivers = yes,
> Monitor mode = yes, Packet injection = yes, Promiscuous=?

Monitor mode = promiscuous.

Bear in mind your Bullet is a little linux box so some of the tools you
would run on your linux laptop could be persuaded to run on the Bullet. For
example you might be able to get Kismet to run in drone mode on the Bullet.
I use a little tool called 'wavemon' for simple signal strength [once
associated] testing with wireless.

--
<http://ale.cx/> (AIM:troffasky) (UnSoEsNpEaTm@ale.cx)
21:39:44 up 29 days, 1:09, 3 users, load average: 0.12, 0.17, 0.14
"People believe any quote they read on the internet
if it fits their preconceived notions." - Martin Luther King

On Thu, 09 Feb 2012 21:47:18 +0000, alexd <troffasky@hotmail.com>
wrote:

> "People believe any quote they read on the internet
> if it fits their preconceived notions." - Martin Luther King

I've seen the same quote attributed to Thomas Jefferson, which is even
better than faking it with MLK. Do you know who actually said it?

On 2/9/2012 5:48 PM, Char Jackson wrote:
> On Thu, 09 Feb 2012 21:47:18 +0000, alexd<troffasky@hotmail.com>
> wrote:
>
>> "People believe any quote they read on the internet
>> if it fits their preconceived notions." - Martin Luther King
>
> I've seen the same quote attributed to Thomas Jefferson, which is even
> better than faking it with MLK. Do you know who actually said it?
>


Karl Rove

On Thu, 09 Feb 2012 21:47:18 +0000, alexd <troffasky@hotmail.com>
wrote:

>Monitor mode = promiscuous.

Not exactly. See:
<http://airsnort.shmoo.com/faq.html#Q3>

>I use a little tool called 'wavemon' for simple signal strength [once
>associated] testing with wireless.

<http://www.techspikes.com/2009/12/wavemon-wifi-signal-monitor/>
Very cool. Works nicely on Ubuntu 11.10. Thanks.

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

On 2/9/2012 9:29 AM, Jeff Liebermann wrote:
> On Thu, 9 Feb 2012 16:26:32 +0000 (UTC), Chuck Banshee
> <chuckbanshee@private.com> wrote:
>
>>> If you are aiming with a compass, is it a real compass
>>
>> I'm aiming by signal strength, as read by the radio screwed onto the back
>> of the antenna.
>>
>>> The Cammenga compass is the only way to aim an antenna
>>> http://www.cammenga.com
>
>> I see. Very nice. Rugged looking. With good directional aids.
>
> I never use a compass. Too many errors when working with high gain,
> narrow beamwidth antennas, which need better accuracy.
>
> Instead, I use a road map, some pins, and a piece of plywood. Locate
> yourself on the map. Insert a pin. Locate a landmark (e.g. mountain
> top) that you can see. Insert a 2nd pin. Sight between the two pins
> and rotate the map. Now, the map and the planet are identically
> oriented. Find your target on the map, insert a 3rd pin, sigh between
> your location and the target, and point your antenna the same way. I
> can do about +/- 1 degree this way (if I'm careful or use a
> theodolite). You can't even get close to that with a compass.
>
> Also, don't aim by signal strength unless you have perfect line of
> sight. If you happen to pick a reflection, rather than the incident
> signal, it's not going to be stable. When the wind blows, the signal
> will change. Best to aim the antenna geographically, tolerate a
> somewhat lower signal level, and not have it change later.
>
>

The Cammega is quite a instrument if used carefully. The military spec
is 40 mils, but the manufacturer states 2 mils. At that point, the
uncertainly in the magnetic compensation is a larger error.

You do need to watch out for stray iron. There is a photo of someone
using a lensatic with a freakin' locomotive behind him.

If you do decide to purchase a Cammenga, the phosphorus one is fine. It
is not like you are in special ops. If you want to use it at night, just
"charge" it with your flashlight.

Obviously for satellite work, you aren't getting reflections. ;-)

>
> So far, by googling, I've found only one radio that does this:
> Alfa Network AWUS036H ($28), TX=20dBm (100mW), RX=-91dBm@11Mbps802.11b
> Antenna=2dBi omni,
> Power = USB, Linux drivers = yes,
> Monitor mode = yes, Packet injection = yes, Promiscuous=?

The AWUS036H works fine with kismet. They have a 1 watt version.

>
> But if I'm going to buy anything, I prefer a stronger gain such as this 1
> Watt USB radio (but I don't know if it is promiscuous):
> Alfa Network Tube-U(N), TX = 30dBm (1 Watt), RX = -95dBm@ 1Mbps802.11b
> Antenna Connector=N-Type Male (so you can add any antenna you like
> Power = USB, Linux drivers = yes,
> Monitor mode = ?, Packet injection = ?, Promiscuous=?

I have the tube/u. It is less power than the AWUS036H. It works fine in
Kismet.

Incidentally, Kismet is totally passive. I'd have to research packet
injection, but that sounds like something active.

>
>> quality of signal is what you want rather than signal strength.

One you have comms, the firmware will yield a quality signal. I will
admit I don't know how they get this figure of merrit, but it seems to
be what you want to optimize.
>
> Interesting. I was going for pure decibels. Is transmit CCQ the quality
> metric I try to maximize? If not, I don't know what other 'quality'
> metric to aim for that I can measure at the radio.
>
> I'm currently using the 19dBi Laird Technologies PA24-19 from Streakwave
> in San Jose, installed on the antenna mast along with the 28dBm (630mW)
> Bullet M2 radio so I'm familiar with that suggested brand (and I like
> them).
>

I can see that antenna being a bit tricky to set up due to the lobes.

> In addition, if I buy the 1 Watt Alfa Network bullet USB radio, I'll need
> an additional external antenna. The antenna consumes 100 Watts though, so
> I'm not sure if that can be handled by the USB port (because 500mA USB x
> 5 volt USB is only 2.5 Watts)
>
My point was to hook up the wifi dongle and just monitor. That would be
from your existing antenna. You might find that you are fighting with
some other source.


>> the lobes of the 19dbI antenna are down about 12 dB.
>> I preferred to use the 16dbi version, while has lobes that are further
>> down and much more to the side.
>
> Of the three Laird antennas on that datasheet, I agree, the lobes of the
> 16 dBi version are cleanest (by far)!
>
> One potential issue with the 16 dBi antenna is that, of the three, it's
> the only one that doesn't support "surface mounting". What is "surface
> mounting" anyway? They all support 1" to 2" pole mounting, which I'm
> familiar with. But what is surface mount anyway?

I got the impression the whole family of antennas is similar except for
dimensions. Mine is pole mounted.
>
> In the end, it cost me as much (or more) than it would have for him to do
> the work - but I have a better installation - and I can control the radio
> and the settings.

And you are a better person for this! There is a lot to be said for
knowing exactly what you have installed and how it was set up. I can't
tell you how much money I wasted on a gate control company that was
reaming me for repairs on what I finally determined was a PCB with an
intermittent bug. [You could push it and signals would change.] I
bypassed the service company and arranged to get the board swapped.
Problem solved, and the gate guy doesn't get to make a boat payment.

>
>> Do you know if you have line of sight? Are there tree in the way?
>
> I've never visually 'seen' the WISP antenna but the WISP came to my house
> and said there was line of sight and he gave me the coordinates to his
> antenna (which I posted in the picture in the first post).
>
>
> That kind of stuff is EXACTLY why I want to find good sniffer software
> that works on the Linux laptop (along with a good external antenna& USB
> radio for that laptop)!
>

I don't think you want to sniff your local environment. I think sniffing
with the antenna is the way to go. I'm going to go back and try to find
the coordinates you mentions, but it has been my experience that
mountain tops are full of wifi these days. It seems some companies use
wifi as a way to remotely read their instrumentation. Maybe all that
wifi causes your receiver to think it has a strong signal.

Normally I just do a point to point where there is just one source at
each location. Now probably a question for Jeff would be is there a way
to see if one direction is working well, but not the other. Perhaps the
WISP has interference from your direction, so link that is your
transmitter to their receiver is poor, but you can "hear" the WISP just
fine.

On Thu, 09 Feb 2012 17:19:04 -0800, miso <miso@sushi.com> wrote:

>The Cammega is quite a instrument if used carefully. The military spec
>is 40 mils, but the manufacturer states 2 mils. At that point, the
>uncertainly in the magnetic compensation is a larger error.

Yep. Maybe they should call it resolution instead of accuracy? I
suppose someone could resolve 2 mils (2 milliradians) or 0.11 degrees,
which is about the width of the reticule wire. However, that's
useless if the north reference (the compass needle) isn't any better
than maybe +/-2 degrees (or worse). With the map table method,
there's no magnetic variation, no guessing the center of swing on the
needle, and no transfer error. The military standard of 40
milliradians (+/-2.30 degrees) seems more reasonable, but still seems
too small.

>You do need to watch out for stray iron. There is a photo of someone
>using a lensatic with a freakin' locomotive behind him.

Amazing. I guess we can do away with all the licensed compass
adjusters in the marine and aviation business with such a simple
invention.

>Obviously for satellite work, you aren't getting reflections. ;-)

Unless you're in a canyon, where reflection from the canyon walls
cause problems. Same with urban canyons with reflections from
buildings.

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

On Thu, 09 Feb 2012 18:07:52 -0500, News <News@Group.Name> wrote:

>On 2/9/2012 5:48 PM, Char Jackson wrote:
>> On Thu, 09 Feb 2012 21:47:18 +0000, alexd<troffasky@hotmail.com>
>> wrote:
>>
>>> "People believe any quote they read on the internet
>>> if it fits their preconceived notions." - Martin Luther King
>>
>> I've seen the same quote attributed to Thomas Jefferson, which is even
>> better than faking it with MLK. Do you know who actually said it?
>>
>
>
>Karl Rove

A quick Google didn't turn up any support for that, nor did I find the
origins of the Martin Luther King (or Thomas Jefferson)
misattribution. I guess it goes unanswered for now, not to mention
being OT, for which I apologize.

On Thu, 09 Feb 2012 16:24:23 -0800, Jeff Liebermann wrote:
>>Monitor mode = promiscuous.
>
> Not exactly. See:
> <http://airsnort.shmoo.com/faq.html#Q3>

Thanks Jeff. That web site makes it clear that both modes capture
packets ... but that one mode requires association while the other mode
doesn't.

Q: What is the difference between monitor and promiscuous mode?

Monitor mode enables a wireless nic to capture packets without
associating with an access point or ad-hoc network.

Promiscuous mode allows you to view all wireless packets on a network to
which you have associated.

On Thu, 09 Feb 2012 16:24:23 -0800, Jeff Liebermann wrote:

>>I use a little tool called 'wavemon' for simple signal strength [once
>>associated] testing with wireless.

Wavemon is in the Ubuntu Software Center, which describes it as:

Wavemon allows you to watch signal and noise levels, packet statistics,
device configuration and network parameters of your wireless network
hardware. It has currently only been tested with the Lucent Orinoco
series of cards, although it should work (though with varying features)
with all devices supported by the wireless kernel extensions by Jean
Tourrilhes.

I will install this wavemon and test it out!

Thanks!

On 2/9/2012 6:15 PM, Jeff Liebermann wrote:
> On Thu, 09 Feb 2012 17:19:04 -0800, miso<miso@sushi.com> wrote:
>
>> The Cammega is quite a instrument if used carefully. The military spec
>> is 40 mils, but the manufacturer states 2 mils. At that point, the
>> uncertainly in the magnetic compensation is a larger error.
>
> Yep. Maybe they should call it resolution instead of accuracy? I
> suppose someone could resolve 2 mils (2 milliradians) or 0.11 degrees,
> which is about the width of the reticule wire. However, that's
> useless if the north reference (the compass needle) isn't any better
> than maybe +/-2 degrees (or worse). With the map table method,
> there's no magnetic variation, no guessing the center of swing on the
> needle, and no transfer error. The military standard of 40
> milliradians (+/-2.30 degrees) seems more reasonable, but still seems
> too small.

Do what you think you need to do. I'm just saying it is a cinch to set
up antennas with a good compass if you know what you are doing.
>
>> You do need to watch out for stray iron. There is a photo of someone
>> using a lensatic with a freakin' locomotive behind him.
>
> Amazing. I guess we can do away with all the licensed compass
> adjusters in the marine and aviation business with such a simple
> invention.

I'm not sure why you are trying to be snide here. With flux gates, there
are ways to compensate for local fields. You can't do that with a
handheld compass.
>
>> Obviously for satellite work, you aren't getting reflections. ;-)
>
> Unless you're in a canyon, where reflection from the canyon walls
> cause problems. Same with urban canyons with reflections from
> buildings.
>

I haven't run into such problems.

There is an iphone app for setting up satellites. Oh, and it has glowing
reviews.

> http://www.dishpointer.com/category/iphone-apps/

Of course, the basis for this program is the crappy iphone compass.

Chuck Banshee (for it is he) wrote:

> I will install this wavemon and test it out!

You might want to try it with something other than gnome-terminal as I find
that tends to intercept the function keys when switching between screens.
Not sure if the GNOME terminal is the default on the Ubuntu desktop at
present. xterm will probably be installed, if not I prefer Konsole from KDE
as you can split tabs horizontally and vertically and see [say] ping output
at the same time as wavemon's histogram.

--
<http://ale.cx/> (AIM:troffasky) (UnSoEsNpEaTm@ale.cx)
21:50:55 up 30 days, 1:20, 3 users, load average: 0.17, 0.15, 0.10
"People believe any quote they read on the internet
if it fits their preconceived notions." - Martin Luther King

On Fri, 10 Feb 2012 00:31:59 -0800, miso <miso@sushi.com> wrote:

>> Amazing. I guess we can do away with all the licensed compass
>> adjusters in the marine and aviation business with such a simple
>> invention.
>
>I'm not sure why you are trying to be snide here. With flux gates, there
>are ways to compensate for local fields. You can't do that with a
>handheld compass.

Sigh. No insult was intended. It's just that if the compass offered
the accuracy indicated in the data sheet (0.11 degrees), there would
be no need for compass adjusters. The problem is not the compass, but
rather that they used and mixed the terms "accuracy" and "resolution".
The 0.11 degrees is really the resolution, which means that a fairly
normal human can possibly resolve two objects separated by 0.11
degrees. I just tried it on my cheapo hiking compass. The best I can
do is about 1.5 degrees, mostly due to the lack of a reticule wire.
However, that's resolution, not accuracy. My ability to locate true
north would be a measure of accuracy. Comparing the compass with my
Droid compass results in about a 5 degree discrepancy (after
compensating for magnetic variation). I can't really call that the
accuracy, but it's in the ballpark.
>>
>>> Obviously for satellite work, you aren't getting reflections. ;-)
>>
>> Unless you're in a canyon, where reflection from the canyon walls
>> cause problems. Same with urban canyons with reflections from
>> buildings.
>
>I haven't run into such problems.

Patience, you will run into such problems:
<http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System#M ultipath_effects>
I had an ancient Magellan GPS that would nuts when faced with
reflections. My dragon droppings were all over the screen while
driving through the local canyons. Also, we have a local Geocaching
stash, that's located at the bottom of a highly reflective canyon.
Those with WAAS over-ride features can usually find it after some
frustration. Those without are usually faced with multiple
contradictory positions.

>There is an iphone app for setting up satellites. Oh, and it has glowing
>reviews.
>
>> http://www.dishpointer.com/category/iphone-apps/
>
>Of course, the basis for this program is the crappy iphone compass.

I have both an old Droid A855 phone, and an iPhone 3G. The compass
and GPS on the Droid are MUCH better than the iPhone. One Droid app
provides a combination on screen compass and bubble level, which
really helps with the accuracy.

The satellite pointing apps are kinda nice for determining if there's
a possibility of getting DBS reception. I have that problem in the
local forest. However, since I'm not using the app for dish
alignment, lousy accuracy is just fine. My current setup is a soda
straw, taped to an inclinometer and a compass. It works well enough.
My only problem is that many of the dish aiming web sites don't bother
to distinguish between magnetic north, and true north.

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

On Fri, 10 Feb 2012 17:38:43 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>The satellite pointing apps are kinda nice for determining if there's
>a possibility of getting DBS reception. I have that problem in the
>local forest. However, since I'm not using the app for dish
>alignment, lousy accuracy is just fine. My current setup is a soda
>straw, taped to an inclinometer and a compass. It works well enough.
>My only problem is that many of the dish aiming web sites don't bother
>to distinguish between magnetic north, and true north.

I've used www.dishpointer.com a half dozen times in the past year and
have never failed to find the intended target within a few minutes, at
most. I don't know or care how they handle magnetic deviation, I just
use the provided map and there's the sat. Easy peasy.

On Fri, 10 Feb 2012 19:55:25 -0600, Char Jackson <none@none.invalid>
wrote:

>On Fri, 10 Feb 2012 17:38:43 -0800, Jeff Liebermann <jeffl@cruzio.com>
>wrote:
>
>>The satellite pointing apps are kinda nice for determining if there's
>>a possibility of getting DBS reception. I have that problem in the
>>local forest. However, since I'm not using the app for dish
>>alignment, lousy accuracy is just fine. My current setup is a soda
>>straw, taped to an inclinometer and a compass. It works well enough.
>>My only problem is that many of the dish aiming web sites don't bother
>>to distinguish between magnetic north, and true north.

>I've used www.dishpointer.com a half dozen times in the past year and
>have never failed to find the intended target within a few minutes, at
>most. I don't know or care how they handle magnetic deviation, I just
>use the provided map and there's the sat. Easy peasy.

I don't have problems finding the satellite. No augmented reality is
necessary to aim the dish. Make sure the pipe is vertical with a
bubble level. Set the elevation to the calculated angle. Spin the
dish around the estimated azmuth while watching the inline signal
strength meter.

The area where augmented reality and similar apps are handy is
determining if reception is going to be possible through the trees. If
you can see the sky through the camera, it will work. If you're
looking at trees, move or get the chain saw.

I was tempted to try the app, but they want $20 each for the iphone
and Droid version. No thanks.

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

Oh yeah, GPS and reflections, that I get. I meant FTA. I'm amazed GPS
even works as well as it does.

An analog compass would resolve infinitely. Precision is another story.
;-) I suspect if the manufacturer provided the DUT setup, all they are
doing is indication how accurately north is marked on the dial.

I can testify my Garmin gps60 compass is a POS. That is why I bring a
real compass. Worse of all, the gps60 attempts to use the compass if you
are not moving fast enough for a virtual compass (sequential position
difference). But the built in compass is such a POS that you are better
off at all times with the differential scheme. If you dig deep enough,
you can change the switch over portion.

Newer GPSs have a 3D compass. No requirement on how it is held.

>
> I was tempted to try the app, but they want $20 each for the iphone
> and Droid version. No thanks.
>
Hopefully not stating the obvious, but this free program, a location
waypoint and a good compass is all you need.
> http://www.al-soft.com/saa/satinfo.shtml

Oh, and a sat meter.

On Sat, 11 Feb 2012 13:48:30 -0800, miso <miso@sushi.com> wrote:

>> I was tempted to try the app, but they want $20 each for the iphone
>> and Droid version. No thanks.

>Hopefully not stating the obvious, but this free program, a location
>waypoint and a good compass is all you need.
>> http://www.al-soft.com/saa/satinfo.shtml

That's for the PC, not the iPhone or Droid. The program calculates
the predicted azimuth and elevation, but doesn't answer the basic
question of whether the satellite is visible from the customers
location. It's a rather nice program. Too bad that it doesn't bother
to mention whether the azimuth is true or magnetic. Also, it
installed ReleventKnowledge spyware without asking.
<http://www.relevantknowledge.com>
Fortunately, it can be separately uninstalled with add-and-remove.

Also, please note that my comments on using a map board has nothing to
do with satellite dish pointing. My comments were on dish aiming
between a WISP antenna, and wherever the WISP has their central access
point. The problem in my area is that from the tree tops, all you can
see are more tree tops. Aiming points are few. If I have a visual
aiming point, I try to bore-sight the antenna. However, without an
aiming point, I have to calculate the direction, pre-align the dish,
hope I can get a signal, and then tweak for best signal. That's not
easy with a 24dBi dish with a 4-8 degree beamwidth.

>Oh, and a sat meter.

Yep. I have several. The $7 cheapo meters are adequate.

Incidentally, another method I use for DBS dish qualification uses the
bi-annual solar outage. Finding where on my roof to position the dish
is tricky as I'm shooting through a hole in the tree canopy. Since
the tree grow, the hole moves.
<http://802.11junk.com/jeffl/pics/DBS/index.html>
At the designated date and time, the sun is directly behind the
satellite. Where my roof is illuminated, are possible dish locations.
In California, the next event will be between Mar 1 and Mar 8, 2012.


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

>
> Which is exactly why I build my own antennas rather than buy
> from some jerkoff outfit on the web that thinks they can dictate
> ridiculous terms and outrageous return policies, like the ones
> you keep promoting and you probably have a $$ stake in.

Surprise surprise, non of these companies I suggest pay me a cent. They
just take my money and ship me stuff that works.

I roll my own antennas when I can't find something better, but it is
just stupid to spend time and money on something easily purchased. Oh,
and I do my homework and look at the antenna specs so I don't have to
return them.

On 2/12/2012 9:31 PM, Jeff Liebermann wrote:
> On Sat, 11 Feb 2012 13:48:30 -0800, miso<miso@sushi.com> wrote:
>
>>> I was tempted to try the app, but they want $20 each for the iphone
>>> and Droid version. No thanks.
>
>> Hopefully not stating the obvious, but this free program, a location
>> waypoint and a good compass is all you need.
>>> http://www.al-soft.com/saa/satinfo.shtml
>
> That's for the PC, not the iPhone or Droid. The program calculates
> the predicted azimuth and elevation, but doesn't answer the basic
> question of whether the satellite is visible from the customers
> location. It's a rather nice program. Too bad that it doesn't bother
> to mention whether the azimuth is true or magnetic. Also, it
> installed ReleventKnowledge spyware without asking.
> <http://www.relevantknowledge.com>
> Fortunately, it can be separately uninstalled with add-and-remove.
>
> Also, please note that my comments on using a map board has nothing to
> do with satellite dish pointing. My comments were on dish aiming
> between a WISP antenna, and wherever the WISP has their central access
> point. The problem in my area is that from the tree tops, all you can
> see are more tree tops. Aiming points are few. If I have a visual
> aiming point, I try to bore-sight the antenna. However, without an
> aiming point, I have to calculate the direction, pre-align the dish,
> hope I can get a signal, and then tweak for best signal. That's not
> easy with a 24dBi dish with a 4-8 degree beamwidth.
>
>> Oh, and a sat meter.
>
> Yep. I have several. The $7 cheapo meters are adequate.
>
> Incidentally, another method I use for DBS dish qualification uses the
> bi-annual solar outage. Finding where on my roof to position the dish
> is tricky as I'm shooting through a hole in the tree canopy. Since
> the tree grow, the hole moves.
> <http://802.11junk.com/jeffl/pics/DBS/index.html>
> At the designated date and time, the sun is directly behind the
> satellite. Where my roof is illuminated, are possible dish locations.
> In California, the next event will be between Mar 1 and Mar 8, 2012.
>
>
Most remote radio goes over ISDN lines these days. But when Dr. Dean
Edel had his radio show, it obviously went out over the bird because the
signal would be lost.

I forgot to mention "relevant knowledge." The MS antivirus rips it off.
The direction is true, not magnetic. I suppose they could do a magnetic
adjustment since you give it your coordinates.

Another good resource is satbeams.
> http://www.satbeams.com/

They give you the foot print of the bird. Not really all that useful for
dish or direct, but handy for FTA.