Richard Clark wrote:

And to invert the argument. When I lived in Europe in the late 50s
early 60s, Paris had such a funky telephone system that reportedly you
could dial a "special number" that put you into an open common trunk
where others would have been already deep in spontaneous conversation.
It was very popular and "exciting...." until they fixed it (in their
own time, of course - for the French that could have been many years
later).

73's
Richard Clark, KB7QHC

It probably wasn't "funky". It was just hacked.

It also existed in the US. The chances are that it was the same
destination type as it was here. In the US you could dial a number that
effectively put you into a conference. It was used for telco meet-me
maintenance traffic. Neither person needed to know the other's number.
I know someone that used to do music requests to their 6 MHz
(plus/minus) pirate broadcasts using this hidden conference bridge.
They were the first on the air as a pirate station in the US as far as I
know.

I don't condone it, but it was a long time ago, and the persons involved
have paid their dues. And are all good taxpaying citizens now.

tom
K0TAR

"Sal M. Onella" wrote in message
...



Why not go find a couple of el cheapo PRS handi-talkies (Personal Radio
Service - 450 plus MHz) and let the kiddies talk to each other that way?
Why
bring ham radio into it at all?

It was by way of introducing them to our hobby in the course of giving
a lesson. That's all.

Thanks for your input.

"Sal"


Sal, who do you suppose that they will talk to if they did take the bait and
get a license and a radio?

I've heard kids calling CQ many times, only to go unanswered - even by me, I
shamefully admit. I leave my ham rigs running while I'm working in my shop,
so I seldom answer anyone's CQ if I'm busy working, so the kids weren't a
special case, although I did feel guilty that I didn't answer their call.


Ed, NM2K

On Tue, 15 Dec 2009 17:42:25 -0800 (PST), "Sal M. Onella"
wrote:

I have a diverse collection of demonstrations for them, hoping to
catch each one of them with something they find interesting.

Perfect. That's the right idea. Lots of show and very little tell
(unless they ask).

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?

They're mostly 4th graders. I'm doing magnetism and
communications and showing how they relate.

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. Getting my
attention for only a few minutes was easy. More than an hour was
impossible. Somewhat later, I took the ones that were of interest and
went deeper. I still recall round the clock repeater building
sessions in my fathers garage.

I taught school in the
Navy, but I have no experience with little kids, except my own.

When I took teacher prep, one of the first exercises was to reduce my
vocabulary to about 9,000 words which was about right for a 12 year
old. I later found out that the typical 12 year old knew far more
words than officially recognized. Just avoid any technobabble with 3
or more syllables and you'll do ok. Try to get them to ask questions
and answer the questions at the same level as was asked.

My
Navy students were almost always well-motivated but I have no idea
what the 4th graders are going to be like.

They will be out to see how far they can push or taunt you. Don't
fight it. Just be their friend and not their diciplinarian. If they
go over the top and riot, then maybe sacrifice the leaders for the
greater good. Smart kids are much easier to deal with than the
academic losers. My favorite line for getting them curious is "wanna
see what's inside" or "wanna know how this thing works"? Don't be
surprised if you get high level questions. Most of these kid so read
magazines and techy stuff online, mostly ammunition to make themselves
look good in class. Be prepared to answer tough basic questions like
"why does one radio talk around the world, while others just talk down
the street"? You might learn as much from their questions as they're
learning from your demo.

They are all in the
Gifted And Talented Education program and I think it's either going
to be great or awful -- no in-between.

In the accellerated classes, they'll all be trying to show off how
much (or little) they know.

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

On Tue, 15 Dec 2009 17:42:25 -0800 (PST), "Sal M. Onella"
wrote:

I taught school in the
Navy, but I have no experience with little kids, except my own. My
Navy students were almost always well-motivated but I have no idea
what the 4th graders are going to be like.

I know what you mean because our experience has converged there.
Outside of the Navy, and just yesterday, I was Mentoring 3 of my high
school students to varying degrees of success. When asked how it
went, I responded "up, down, and sideways." Luckily this response is
not the typical experience. These kids are from the lower end of the
socio-economic spectrum, but the school system here in Seattle has
made an investment, and community (I do this through the NW Assoc. for
Biological Researcher) does its part to. Computer literacy is tops
(without the golden hand of Chairman Bill Gates being felt). From
their interest and drive, their challenged background (or challenged
emotional/developmental life) doesn't disrupt their momentum.

One of the most profound lectures I have ever read, insofar as
teaching science goes, dates back roughly 150 years to one of our own.
"The Chemical History of the Candle" by Michael Faraday is a series of
lectures by the master of inductance given to young students. It is
the classic of its type and sets the standard even to this day.

One might ponder about the significance of a history of the candle. In
one sense, it is quite complete to that heading alone. But beyond it,
and he goes vastly beyond it, there is coverage that is topical to the
current energy debate, the current green debate, and current to the
state of biology that is understandable by the mid-schooler on.

One point that still astonishes me is when Faraday makes the point
(and I will extrapolate to current capacities) that for every barrel
of oil burned, a barrel of water is produced in the combustion
process. I have to wonder at the plight of science understanding (not
just training) when I see huge flame geysers burning in the desert
(waste gas) of an oil rich country that has to import water:
"What the ****? Over"

73's
Richard Clark, KB7QHC

On Tue, 15 Dec 2009 21:33:23 -0800, Richard Clark
wrote:

"The Chemical History of the Candle" by Michael Faraday
complete text available at:
http://www.gutenberg.org/ebooks/14474

73's
Richard Clark, KB7QHC

On Wed, 16 Dec 2009 01:37:00 -0000, 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.

There's considerable overlap in frequencies in both the 2.4 and 5.7GHz
bands between Part 15 (license free) and Part 97 (ham radio). See:
http://en.wikipedia.org/wiki/High-speed_multimedia_radio#Frequencies_and_channels

Most 802.11 direct sequence modulation on the 2.4Ghz band is about
20Mhz wide leaving exactly 3 non-overlapping channels (1, 6, and 11)
to be used without mutual inference. Some access points have
"automagic frequency selection" which allegedly finds an empty channel
to use. The client radios will follow the access point channel. My
experience with this feature has been dismal and I just turn it off.

The real problem is that direct sequence 802.11 and 802.11b are not
particularly immune to interference. Sure, there's about 10dB of
processing gain, which helps. However, even a dead carrier anywhere
in the 20MHz occupied bandwidth will stop thruput dead. OFDM
(802.11g) does much better by breaking the data into 52 separate
sub-carriers. Clobber a few sub-carriers and all it does is slow
down. However, spray broadband garbage across all 52 carriers (i.e.
microwave oven or frequency hopping spread spectrum, and it too will
stop dead.

So, what are hams doing? Well there's the traditional moon bounce,
DX, and rover modes, all of which are narrow band. They mostly stay
in the bottom part of the band, which does not overlap (much) with
802.11 data. They're not a problem. There are also a very small
number of FM and ATV repeaters on 2.4GHz. Those might become a
problem, if they weren't so rare.

So, where's the problem? Several places, all of which I've seen. One
is from Part 15 wireless network owners purchasing ATV amplifier
hardware and generating what I call an alligator. That's an animal
with a big mouth, but small ears. It can be heard everywhere, but can
only hear a short distance. Kinda like what one gets when attaching a
high power amplifier to a consumer grade wireless router.

Another horror surrounds cordless phones. I caught one bozo with a
modified Panasonic 2.4Ghz spread spectrum cordless phone, with a 10
watt amplifier attached, and using it like a cell phone in downtown
Santa Cruz. I was sniffing the area trying to figure out why wi-fi
was almost useless in parts of the downtown area. This guy wasn't a
ham, but he had some relative that was build him the power amp.

The alligator owners are epidemic and are sometimes hams that have
decided that the Part 97 allows them to use high power regardless of
how much interference it creates. Hams are also a licensed service,
which takes priority over an unlicensed service. However, as I
previously indicated, if the issue ever comes before the FCC, my bets
are on 250 million wi-fi devices, versus 800,000 hams. Chances are
really good that if hams create interference by using high power,
we'll lose the whole band.

The number of conflicts are certainly minimal, as there aren't enough
hams using 2.4Ghz to make a difference. However, one high power ham
ATV xmitter, in the middle of a crowded wi-fi infested area, will
effectively jam everyone within a substantial radius. It only take
one ham operator.



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

Jeff Liebermann wrote in
:

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?


Or make it a puzzle. Some text they're likely to know, maybe a long and
eventful paragraph of Harry Potter or similar, and translate for a short line
that uses only a few letters of the alphabet and that does not identify the
source text or content, but allows substitution to fill in other words,
completed by working out what other parts of the text are saying, or by
simple elimination within a word. I never did learn Morse well, never needed
to, but playing with that method with other people on an internet forum was
by far the closest I ever got, and the most fun. Someone would paste
something into a code translator, and instead of doing the reverse I'd start
with the few I always remember, E,A,N,S,T,O,H, and build on those.

It might sound like a lot for a young child, but if more than one are keen to
find out what's being said they won't need much motivating, that will take
care of itself. They won't remember every letter, but most adults who type
every day would be hard put to locate every letter on a QUERTY keyboard
without actually looking at one, what is retained is the memory of an
important process.

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.

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



- 73 de Mike N3LI -

Richard Clark wrote:


One of the most profound lectures I have ever read, insofar as
teaching science goes, dates back roughly 150 years to one of our own.
"The Chemical History of the Candle" by Michael Faraday is a series of
lectures by the master of inductance given to young students. It is
the classic of its type and sets the standard even to this day.

Thankyew! I'm reading it now. The first thing I am struck by is the
readability of the thing. So much from that era was so hyperliterate.



One point that still astonishes me is when Faraday makes the point
(and I will extrapolate to current capacities) that for every barrel
of oil burned, a barrel of water is produced in the combustion
process. I have to wonder at the plight of science understanding (not
just training) when I see huge flame geysers burning in the desert
(waste gas) of an oil rich country that has to import water:


Most of those places have borrowed the technology to extract the oil in
the first place. It isn't inherent in their lifestyle. They probably
don't know about the water because we didn't tell them. And we were just
worried about the oil.

Excellent point however.

- 73 de Mike N3LI -

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.

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.

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

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.

- 73 de Mike N3LI -
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558