On Dec 14, 1:14*pm, Jeff Liebermann wrote:
On Mon, 14 Dec 2009 17:24:03 +0000 (UTC), "Geoffrey S. Mendelson"

wrote:
Jeff Liebermann wrote:
Yes. *You'll bore the kids to death with such minutae and trivia.
Show them the Jay leno morse code versus texting clip.
Geoff.

The most effective song and dance I did in front of a Jr High Skool
class was tearing apart various cell phones, walkie talkies,
computahs, and consumer electronics to demonstrate that they should
not be afraid of such things. *Unfortunately, the parents hated my
guts when the kids starting practicing what I showed them. *Learn by
Destroying(tm).

2nd best was dragging in my collection of old cell phones including an
IMTS control head, various bag phones, and an unbelievable brick like
handset that's VERY heavy. *I also brought an early Motorola tube type
Breaky-Backy with wet cells inside. *Some of the stuff still works.

Nobody was interested in Morse Code until I mentioned that it could be
used for "secret communications". *That means that the parents and
teachers couldn't understand what the kids were saying. *Lots of
interest (and potential problems) there.

The problem with todays version of ham radio is that it's really
boring. *Nobody wants to talk to someone around the world, when they
can pickup a POTS or cell phone and do it with much less effort and
expense. *With the demise of Heathkit, building radios is no longer a
draw. *The magic of radio is gone. *So, show them what they can do
with radio. *Weather stations, APRS, satellite, construction, etc are
a good start. *

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

LOL I showed showed some kids how to disassembe and reassemble a
desktop computer. I understand a few did well on the disassembly part
but not so well on putting it back together their parents computers.

Jimmie

On Wed, 16 Dec 2009 11:15:41 -0800 (PST), JIMMIE
wrote:

On Dec 14, 1:14*pm, Jeff Liebermann wrote:
The most effective song and dance I did in front of a Jr High Skool
class was tearing apart various cell phones, walkie talkies,
computahs, and consumer electronics to demonstrate that they should
not be afraid of such things. *Unfortunately, the parents hated my
guts when the kids starting practicing what I showed them. *Learn by
Destroying(tm).

LOL I showed showed some kids how to disassembe and reassemble a
desktop computer. I understand a few did well on the disassembly part
but not so well on putting it back together their parents computers.
Jimmie

That's the way we all learn. Next time, they'll do better. You've
hit on one of my many pet peeves. The skools are so afraid of
liability issues that any activity that involves potentially dangerous
tools or devices are proscribed by the administration. The result is
a generation (or two) that don't know which end of the soldering iron
to grab, don't know how to use hand tools, and have zero experience
with machinery beyond simple power tools.

They really have to learn to use such tools early in life or they'll
never learn. A friend of mine's father was an auto mechanic. He
didn't want his son to also become an auto mechanic. Every time his
son would pickup a tool, his father would take it away from him. It
worked. We met when he was about 40 years old. Despite practice and
some instruction, he was a total klutz with hand tool, and a hazard to
life and property with power tools. Try as he might, he couldn't
recover from the lack of childhood experience with tools. However, he
was far from useless. He taught me Unix and some programming in trade
for me maintaining his (Plexus and NCR) servers.

One of my standard birthday (and sometime Hanukah) gifts is a tool box
stuffed full of quality hand tools. I build the kit myself which
includes everything from jewelers screwdrivers to a claw hammer. When
I have time, I hot stamp the birthday brat's name into the plastic
handles, mostly to discourage anyone from borrowing tools. Years
later, the kit is invariably dispersed and half missing, but during
those years, the birthday brat gets some very useful experience with
hand tools.

I was encouraged to take things apart when I was fairly young. I had
my own tool collection by age 7 or so and was encouraged to use it. I
managed to break many things. My father and I would sit down, and he
would fix it. One day, I decided to take apart a brass mantle wind-up
clock. The main spring went boing. Instead of my father fixing it
while I watched, I got to fix it, while he watched. I fumbled,
blundered, and generally made a mess while my father offered advice,
but no direct help. At about an hour a day, we got it back together
and mostly working after about 12 days. I noticed that my father was
sitting on his hands. When I asked about it much later, he said it
wasn't to stop him from grabbing the clock and fixing it himself. It
was to keep him from grabbing my throat and strangling me because I
was doing such a lousy job. Years later, I was rebuilding his factory
sewing machines and later worked on rebuilding teletype machines.
Without that early experience, I wouldn't have had a chance.

Learn by Destroying(tm) which means if you haven't broken it, ripped
it apart, and fixed it, you don't understand how it works.


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

Jeff Liebermann wrote:
On Wed, 16 Dec 2009 11:35:54 -0500, Michael Coslo

No one in their right mind is going to be running that much power -
being line of sight, at those frequencies, there isn't any point.

Most of the Wi-Fi installations are setup to go through walls where
power is helpful. Not exactly line of sight. Some of the outdoor

But. The alligator syndrome gets nailed every time here, although with
some dB recovered due to better receive front ends. But still doesn't
overcome the 30 to 100mW coupled to negative gain antennas on the link
back to the AP.

The semi-exception that I know of, as of about 2 years ago when my
ex-employer ISP that did (somewhat successfully) muni wifi, was testing
and eventually installed, Go Networks APs. They were the only ones at
the time that could use 20W ERP because they were phased array antenna
APs. And they mapped the vector vs MAC address so it knew the best
antenna angle to your PC.

tom
K0TAR

On Wed, 16 Dec 2009 21:25:34 -0600, tom wrote:

The semi-exception that I know of, as of about 2 years ago when my
ex-employer ISP that did (somewhat successfully) muni wifi, was testing
and eventually installed, Go Networks APs. They were the only ones at
the time that could use 20W ERP because they were phased array antenna
APs. And they mapped the vector vs MAC address so it knew the best
antenna angle to your PC.

tom
K0TAR

What "vector"? The beamwidth width was 120 degrees for Go Networks
and 60 degress for Vivato. That's not a beam. That's a barn door.
That nonsense got me rather irate when the FCC concluded that an
overpowerful alligator, with beam steering, will somehow cause less
interference than a sector antenna system.

Go Networks was one of the later vendors to hop on the alligator
bandwagon:
http://wifinetnews.com/archives/2006/04/go_networks_slips_veil_on_cellularmesh_metro_wi-fi.html
They picked up the fumble after Vivato dropped the ball.
http://en.wikipedia.org/wiki/Vivato
To add insult to injury, Go Networks somehow convinced the FCC that
120 degree wide steerable "beams" qualified for the higher power. I
could do better with common sector antennas. At least Vivato used 60
degree beams, which was marginally better. As I recall, their
literature had an illustrators imaginative drawing showing what might
be hundreds of beams with what appeared to be about 5 degree
beamwidth. The illustration also showed the steerable antenna hung on
a wall, thus eliminating half the "beams".

What I saw with the one Vivato 2210 controller I played with was that
the usable range was about the same as a lower powered omni or panel
system because of the alligator effect. The AP was deaf. So was
management.

Incidentally, one local Muni Wi-Fi network turned DOWN their mesh
nodes TX power when they were finally convinced that they were
creating almost all of their own interference. Things worked much
better when the access points and repeaters used approximately the
same tx power as the client radios.

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

On Dec 15, 7:32*pm, Jeff Liebermann wrote:
On Tue, 15 Dec 2009 17:42:25 -0800 (PST), "Sal M. Onella"

wrote:


I have a
handout with eight Morse Code characters on it, enough to spell out
some easy words,

Good idea. *Mind if I steal it?

Feel free g


9-10 years old is the right age to start. *Between 8 and 15, I tried
literally everything I could find. *Cooking, guns, sewing, carpentry,
elecronics (buzzer and magnets), chemistry, fizzix, etc.

No serious Fizzix this time but I already have magnets and buzzers.

*You might learn as much from their questions as they're
learning from your demo.

I'd be surprised if that didn't happen. I'm learning just from the
prep work.

John
KD6VKW

Jeff Liebermann wrote:
On Wed, 16 Dec 2009 21:25:34 -0600, tom wrote:

What "vector"? The beamwidth width was 120 degrees for Go Networks
and 60 degress for Vivato. That's not a beam. That's a barn door.
That nonsense got me rather irate when the FCC concluded that an
overpowerful alligator, with beam steering, will somehow cause less
interference than a sector antenna system.

Go Networks was one of the later vendors to hop on the alligator
bandwagon:
http://wifinetnews.com/archives/2006/04/go_networks_slips_veil_on_cellularmesh_metro_wi-fi.html
They picked up the fumble after Vivato dropped the ball.
http://en.wikipedia.org/wiki/Vivato
To add insult to injury, Go Networks somehow convinced the FCC that
120 degree wide steerable "beams" qualified for the higher power. I
could do better with common sector antennas. At least Vivato used 60
degree beams, which was marginally better. As I recall, their
literature had an illustrators imaginative drawing showing what might
be hundreds of beams with what appeared to be about 5 degree
beamwidth. The illustration also showed the steerable antenna hung on
a wall, thus eliminating half the "beams".

What I saw with the one Vivato 2210 controller I played with was that
the usable range was about the same as a lower powered omni or panel
system because of the alligator effect. The AP was deaf. So was
management.

Incidentally, one local Muni Wi-Fi network turned DOWN their mesh
nodes TX power when they were finally convinced that they were
creating almost all of their own interference. Things worked much
better when the access points and repeaters used approximately the
same tx power as the client radios.


Absolutely right on the power.

I was referring to the panel antennas, not the pole mount units, but
your point is well made. I didn't mean to imply that it was a good
solution.

I modeled the 4 vertical pole mount unit and it's nothing great. At
least the panel versions ended up with some front to back.

Unfortunately, few muni systems seem to use sector antennas. Probably
because you can lose money just as easily with a cheap system as an
expensive one.

I am just glad that I am no longer near the WiFi biz.

tom
K0TAR

Jeff Liebermann wrote:
On Wed, 16 Dec 2009 11:15:41 -0800 (PST), JIMMIE
wrote:

On Dec 14, 1:14 pm, Jeff Liebermann wrote:
The most effective song and dance I did in front of a Jr High Skool
class was tearing apart various cell phones, walkie talkies,
computahs, and consumer electronics to demonstrate that they should
not be afraid of such things. Unfortunately, the parents hated my
guts when the kids starting practicing what I showed them. Learn by
Destroying(tm).

LOL I showed showed some kids how to disassembe and reassemble a
desktop computer. I understand a few did well on the disassembly part
but not so well on putting it back together their parents computers.
Jimmie

That's the way we all learn. Next time, they'll do better. You've
hit on one of my many pet peeves. The skools are so afraid of
liability issues that any activity that involves potentially dangerous
tools or devices are proscribed by the administration. The result is
a generation (or two) that don't know which end of the soldering iron
to grab, don't know how to use hand tools, and have zero experience
with machinery beyond simple power tools.

They really have to learn to use such tools early in life or they'll
never learn. A friend of mine's father was an auto mechanic. He
didn't want his son to also become an auto mechanic. Every time his
son would pickup a tool, his father would take it away from him. It
worked. We met when he was about 40 years old. Despite practice and
some instruction, he was a total klutz with hand tool, and a hazard to
life and property with power tools. Try as he might, he couldn't
recover from the lack of childhood experience with tools. However, he
was far from useless. He taught me Unix and some programming in trade
for me maintaining his (Plexus and NCR) servers.

One of my standard birthday (and sometime Hanukah) gifts is a tool box
stuffed full of quality hand tools. I build the kit myself which
includes everything from jewelers screwdrivers to a claw hammer. When
I have time, I hot stamp the birthday brat's name into the plastic
handles, mostly to discourage anyone from borrowing tools. Years
later, the kit is invariably dispersed and half missing, but during
those years, the birthday brat gets some very useful experience with
hand tools.

I was encouraged to take things apart when I was fairly young. I had
my own tool collection by age 7 or so and was encouraged to use it. I
managed to break many things. My father and I would sit down, and he
would fix it. One day, I decided to take apart a brass mantle wind-up
clock. The main spring went boing. Instead of my father fixing it
while I watched, I got to fix it, while he watched. I fumbled,
blundered, and generally made a mess while my father offered advice,
but no direct help. At about an hour a day, we got it back together
and mostly working after about 12 days. I noticed that my father was
sitting on his hands. When I asked about it much later, he said it
wasn't to stop him from grabbing the clock and fixing it himself. It
was to keep him from grabbing my throat and strangling me because I
was doing such a lousy job. Years later, I was rebuilding his factory
sewing machines and later worked on rebuilding teletype machines.
Without that early experience, I wouldn't have had a chance.

Learn by Destroying(tm) which means if you haven't broken it, ripped
it apart, and fixed it, you don't understand how it works.


Reading this post made me smile, as it brought back so many memories.
When I was a young'un, I had a curiosity that went way past what most
people would call common sense. I disassembled household appliances to
see what made them work. Unfortunately it wasn't until I was 16 or so
that I could put them back together. I tried chemically boring a
lawnmower engine - btw, while hydrochloric acid will attack an Aluminum
cylinder wall very well, it isn't too controllable. 8^) I took so many
things apart that it was starting to become a bit of a hardship, and my
folks were at a loss, because grounding me just gave more time at home
to find things to take apart.

My Grandfather found the answer. He worked at Bendix where they made car
and other radios. There were rejects and prototype radios that the
company would give away. Anyhow, he and I sat down and built a power
supply, and then he let me have at the radios. Ground rules were that I
had to limit my taking apart to the radios, or things my folks were
throwing out.

That was the start of both my electronics interest, and furthered my
total lack of fear to tear things apart. All I know is that it was about
as much fun as I ever had.

- 73 de Mike N3LI -

Jeff Liebermann wrote:
On Wed, 16 Dec 2009 11:35:54 -0500, Michael Coslo
wrote:

Jeff Liebermann wrote:
I don't want to comment on the legal part of the puzzle (because I
already have a headache). However, it should be obvious that there's
a potential conflict between unlicensed Part 15 operation, and
licensed part 97 operation on 2.4GHz. Place your bets and blast a way
with kilowatts on 2.4Ghz. Will 800,000 licensed US hams prevail over
perhaps 300 million unlicensed wireless devices? Want to bet on who
will win before an FCC tribunal? If there is a conflict, I'll place
my bets on Part 15.

No one in their right mind is going to be running that much power -
being line of sight, at those frequencies, there isn't any point.

Most of the Wi-Fi installations are setup to go through walls where
power is helpful. Not exactly line of sight. Some of the outdoor
installations are installed by WISPs (Wireless Internet Service
Providers) that sometimes user maximum legal power amplifiers. You
can also buy relatively high power client radios:
http://www.ubnt.com/products/xr2.php
That's +28dBm or 630mw, which is considerably more power than the
typical 50mw radios. There are also bi-directional power amplifiers
allegedly sold only for ham, government, and industrial use only:
http://www.ssbusa.com/kunamp1.html
and the video equivalent:
http://www.bhphotovideo.com/c/product/505472-REG/RF_Video_AMP_5000M_10_AMP_5000M_10_High_Power.html
from of all places a camera store. I've also helped identify and shut
down 3 such overpowered installations.

What's happening is as the 2.4GHz band gets more and more polluted,
some individuals seem to think that the solution is to increase their
TX power level. That's resulting in a very slow power war. The Wi-Fi
device manufacturers have caught on and are now advertising "high
power" devices, which seems to be anything over +20dBm (100mw).
Various pundits have predicted a power war, which fortunately hasn't
happened.

Regarding your hypothetical situation though, The likely outcome is that
the Amateur would be asked to turn down the power.

That's exactly what has happened in one of the situations that I was
involved. He didn't realize he was causing a problem and was very
cooperative. I also monitor the FCC enforcement actions:
http://www.fcc.gov/eb/AmateurActions/Welcome.html
and have not seen anything on 2.4 or 5.6GHz that required official
action. However, I do know of some warnings sent to WISPs over the
last 10 years or so for using too much power. So far so good.

They usually ask the
two parties to work together to get rid of the interference. But the
real onus is on the part 15 device owner. Dunno if you read the F.C.C.
enforcement actions, but the licensed service still "wins".

That's exactly the problem I mentioned. The licensed ham using 2.4Ghz
is within his rights to use 1Kw. He can also legally cause
interference to unlicensed devices without much consideration. So it
is written, and it must be. However, all it's going to take is a few
industry groups (i.e. lobbying interests) to claim that ham radio
operation on 2.4Ghz is somehow detrimental to the economy by impacting
Wi-Fi equipment sales, and I suspect there will be changes that impact
ham radio. Please consider my comments more as a warning than as a
denunciation.

That was the tactic for the BPL folks. It has to be faced down whenever
they bring it up. The tail should never wag the dog. It becomes doomed
anyhow, because when the device with special privileges starts
interfering with other devices with special privileges, who wins then?
We cannot do an "Animal Farm" Some are more equal than others situation
without chaos.


BPL was an
attempt by economic interests to turn technical reality aside for
pecuniary reasons, but it looks like th elicensed services are going to
win that war now also.

BPL is going to die because the electric utility companies are not
seeing any revenue from the exercise, are getting some really bad
press, and really don't need the hassle. The interference issue gets
the press, but the decisions are always made on the basis of dollars.

BPL proponents allowed people to believe that they were going to just
send the signals along the lines from some sort of "head end" site, and
they would be there for the tapping. In fact, they were a last mile
solution the Fiber would have to be run almost to the house, then the
signal injected into a H-V line - the bpl signals could not survive
going through transformers - finally a device to couple the BPL signal
from the HV to the Household line after the transformer would allow the
signal into the house.

That's bad technology on so many levels it's obvious that the decisions
were based on economics and perhaps some politics (not R vs D, but the
idea that belief trumps science, that the intuitive idea of sending
multiple signals on one wire just has to work.

Are we going to bet our life on that H-V line isolator - injector never
failing closed, and allowing Several KV into our home electrical system?

But the final issue for me was that the source of the data signal had to
come almost to my house. Clean, yummy, digital goodness being degraded
to a shaky easy to disrupt DSL speed signal. No thanks, folks. But let's
talk about get me hooked directly into that fiber, pleeze!


After the ARRL got hold of the original documents
the F.C.C. used during the run up to BPL, and founf out thet the
commission ignored their own engineers findings, then tried to hide that
fact, it kinda let the air outta that tire.

True. Much credit to the ARRL for being able to do that. Still,
nothing has really changed at the FCC end. BPL systems that are
leaking well over established limits are still "working on the
problem". Most are still running in what is becoming a permanent
"trial" mode.
http://p1k.arrl.org/~ehare/bpl/ex2.html

Fortunately, they are going to eventually go away. Unless BPL is going
to become some sort of welfare system with companies sinking money into
it's maintenance for just a few customers.

I had always wondered what was going to happen to BPL systems when the
sunspot cycle hits it's peak.
I'd been assured that propagation wouldn't have any effect on it, but
we'll see.


Meanwhile, a rather large number of HomePlug devices, which is
essentially BPL for home internet, are being sold. They don't leak as
much RF power as real BPL systems, but still manage to make plenty of
noise:
http://www.mds975.co.uk/Content/amateur_radio_BPL_interference.html
Hmmm... It's QRN, not QRM. Oh well.
http://p1k.arrl.org/~ehare/bpl/Testing_HomePlug.htm
At least the ARRL is involved. Some HomePlug devices have
pre-programmed notch filters to reduce power on "sensitive"
frequencies which include ham bands.

All eventually doomed to failure.

If I might conjecture, I think that the current crop of EE's did not pay
any attention to RF while grooming themselves for the brave new future
of "Everything is digital". The HF bands are an unruly beast. They are
prone to static, they are prone to propagation, where at some times a
strong signal can't go much of anywhere, and at other times a milliwatt
works the world. And to make things worse, the propagation varies by
frequency.

For most digital wireless situations, you want a noise free, propagation
free, short range system. HF will never satisfy these requirements. Some
times at sunspot minimum, they might look a little better, but even
then, they just aren't a good choice. Hell, VHF is only just usable.
Gotta be well into UHF before you get good stable conditions

But The new crop of engineers and econo-politicians would like to impose
their digital reality on sections of RF spectrum that just aren't going
to cooperate.


- 73 de Mike N3LI -

Michael Coslo wrote:


BPL was an attempt by economic interests to turn technical reality
aside for pecuniary reasons, but it looks like th elicensed services
are going to win that war now also.

BPL is going to die because the electric utility companies are not
seeing any revenue from the exercise, are getting some really bad
press, and really don't need the hassle. The interference issue gets
the press, but the decisions are always made on the basis of dollars.

BPL proponents allowed people to believe that they were going to just
send the signals along the lines from some sort of "head end" site, and
they would be there for the tapping. In fact, they were a last mile
solution the Fiber would have to be run almost to the house, then the
signal injected into a H-V line - the bpl signals could not survive
going through transformers - finally a device to couple the BPL signal
from the HV to the Household line after the transformer would allow the
signal into the house.

That's bad technology on so many levels it's obvious that the decisions
were based on economics and perhaps some politics (not R vs D, but the
idea that belief trumps science, that the intuitive idea of sending
multiple signals on one wire just has to work.

Are we going to bet our life on that H-V line isolator - injector never
failing closed, and allowing Several KV into our home electrical system?

But the final issue for me was that the source of the data signal had to
come almost to my house. Clean, yummy, digital goodness being degraded
to a shaky easy to disrupt DSL speed signal. No thanks, folks. But let's
talk about get me hooked directly into that fiber, pleeze!


I've always thought that BPL was a solution to getting metering and rate
data to and from the household from the head end. A fairly low rate
application. This has great value to the regulated side of the utility
(smart grid, before it was known as such). The idea that it could be
used for consumer data was probably promulgated by folks who wanted to
sell bigger/better modems, and latch onto "let's wire america" kinds of
funding. Especially if the unregulated side could get income from
infrastructure installed by the regulated side.

wrote:
Jeff Liebermann wrote:
On Tue, 15 Dec 2009 16:14:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

wrote:
It is not illegal if it is done on an amateur frequency by a licensed amateur.

You forgot the words "in the US".
Is using WiFi equipment for ham radio legal?
Geoff.

I don't want to comment on the legal part of the puzzle (because I
already have a headache). However, it should be obvious that there's
a potential conflict between unlicensed Part 15 operation, and
licensed part 97 operation on 2.4GHz. Place your bets and blast a way
with kilowatts on 2.4Ghz. Will 800,000 licensed US hams prevail over
perhaps 300 million unlicensed wireless devices? Want to bet on who
will win before an FCC tribunal? If there is a conflict, I'll place
my bets on Part 15.

Since 2.4 GHz is basically line of sight, few hams work 2.4 GHz, and the
Part 15 devices running under Part 15 can hop to other frequencies
including frequencies outside the ham bands, I don't see a lot of
potential for conflicts.

In the Netherlands, the part of the 2400-2450 MHz band has been taken
away from radio amateurs except for use in the amateur satellite service.

This has been done to prevent interference to wireless devices, which
are limited to even lower power here.
Before this regulation change, a radio amateur could use higher powered
devices (e.g. from the US market) and build point-to-point links on
the lower channels with high EIRP.

But now it is no longer allowed. We can only use 2320-2400 MHz, so
any 802.11 devices first need to be modified to transmit below 2400.