Not an explanation I have been given, but instead gave to someone of whom I later told it was a joke. An employee at the office I was working out of had to get his laptop on the network and it would not get an address. Well, the line was showing good to the tester but I went ahead and re-terminated it as a crossover instead. This ended up fixing the problem (the wall plate had been terminated wrong) but he was not in the office when I fixed it. I glanced behind his desk and there was a whole bundle of CAT5 back there, I pulled out a particular strand of it and when he came back in to ask the problem I told him the line was kinked and the electrons couldn't get through, just like a water hose when it is kinked. He bought it even though he use to be a service tech at an RF amplifier company! Couldn't stop laughing for half the day. I did tell him the real problem afterwards.
What's bad is even though Cingular may be fighting this, about 6 months ago they made the company I work for change all of its cellphone numbers from numbers that any of our offices could call with out dialing long distance to a single block of local numbers with the excuse that they were complying with the new number portability requirement set forward by the FCC.
Good ol' MTU alumni. While I was there (93-98) my roomies and I had a spud cannon building party. We used 4" (ID) combustion chambers that were about 1.5' long that reduced into 2" (ID), 4' long barrels. The end of the combustion chamber had a screw off lid for spraying in the propellant. We used apples, especially during deer season (Michigan people will understand that) and cheap hair spray (tried ether and WD-40). One of my roomies used a piezo igniter from a bbq grill and I used an old flash unit from a 110 camera. It was neat to hear mine whine as it charged up, then the light would come on and I used a nail inserted into one side to short out a large bolt on the other. The 300vdc coursing through that short was enough to burn my roomies arm when he decided to see if it would shock him and blow two chunks of metal off of a pocket knife blade.
We would go behind DHH and fire off into the Portage Canal. We guesstimate that we could reach half way on a good day. The blue flame leaving the barrel in the middle of the night and echoes of the booms off the side of the "Ditch" rocked:)
Anyways, as far as schools are concerned...Not sure in NYC.
Something like this back in '98 or '99
on
Robocoaster
·
· Score: 1
I saw something like this back in 1998 or 1999 at Union Station in St. Louis. It was on the second floor by the rest of the arcade games. It had a fully enclosed cockpit that had a screen in it. The cockpit spun 360d on the arm it was mounted to which could also sping 360d with no chance of ever hitting the ground. Two people could ride it, it had a 500lb occupancy limit. While it was going, people could watch a monitor on the outside near the ride that showed what the people on the ride were seeing. It had a nice soundtrack that would play in the background along with all the normal rollercoaster sounds and as it went through the ride you'd hear the occupants screaming and change falling out of their pockets just like on a regular coaster. Unfortunately I never saw who the manufacturer was but maybe someone else on here from St. Louis may have also seen it before?
Reminds me of a movie
on
Ants Invade iBook
·
· Score: 3, Informative
Anybody see the independent movie PI? The mathematician's "super computer" gets infested with ants in the beginning and prompts him to make a deal with someone for the best chip out there in return for research into the magic number (sort of like the unified theory but different).
Hmm, I'm not sure where you are getting your salary statistics. When I reviewed the starting salaries, back in '98, upon graduation from the university that I attended it revealed that female starting salaries in most engineering fields were slightly higher than that of new male hires. Notice I said most engineeing fields. There were still a few engineering fields that salaries were significantly higher.
First off, isn't the 2.4GHz band an ISM band? Meaning that there are also medical devices that operate and are prone to receiving interference in this band. It would be hard to believe that something like this is targetted at hospitals. I've done RF interference testing on medical and lab instruments. Generally we did tests with anything that created RF like the maintenance walkie talkies that transmitted in the VHF/UHF range at about 5W output. We would test with radio keyed at the case of the instrument, 6" away, 1' away, 3' away, 10' away and if it still caused some type of malfunctions in the instrument under test we would keep moving further away until it stopped interfering.
Also, in clean rooms such as ER (I've never been in ER but I've been in other clean rooms down to a Class 100), they use a flush mounted phone that has a flat, cleanable face with no holes in it that can not only be dialled out on, but also has a programmable memory for speed dialling.
If the companies are monitoring for so called cyberslacking it may not matter much if you are using SSL/SSH with your instant messaging. There is software for monitoring the users' desktops and keystrokes which is one of many tools that employers can use, not only packet/traffic monitoring on company networks. Just to add another formula to things, monitoring can be completely seperate from the computer, they (employers) can also use well placed CCTV systems.
I'm also an amateur licensed operator and I have to disagree. The
only time that spread spectrum use in the amateur allocations would
have a possibility of interfering would be for the weak signal guys
such as the ones that bounce their signals off the moon.
Interference for storm chasing or repeater operation, both of which
are done on FM, would not be noticed even though the noise floor
would be raised (only marginally) since all you would do would be
to turn the squelch up or turn on a code squelch such as Motorola's
PL (CTCSS in amateur radio) tones.
http://www.tapr.org for more info.
Of course you didn't look at any of the spectrum above 20GHz? Is this because of cost/feasibility or just information available to you? Above 300GHz nothing is licensed. Of course once one reaches a high enough power level regulations come into play like with lasers which are in the THz(?) range.
Unfortunately on the lower frequencies they cannot be attached to the land beneath the expected coverage because of propagation issues which may cause interference in another cell or plot of land. Once one reaches a high enough frequency (above the 300GHz range, again possibly in the THz range) it can be land area specific because of specific attenuation by the atmosphere. This could then be used to create thousands/millions of tiny cells with a very large amount of bandwidth, since bandwidth available ultimately increases with frequency, that would not cause intereference with each other because they would be land area specific.
DSSS or Direct Sequence Spread Spectrum. Without getting too technical a psuedo-random noise code or PN code is used. The information is mixed with the PN and then 'spread'. When the signal is received, the PN the receiver has is compared to the PN in the spread signal. If they are the same, the PN is subtracted from the signal and you have your information back. If the PN codes are different then the signal is just noise hence being able to have more than one transmitter in a given bandwidth. Now keep in mind this is really generallized (for those EE's that feel like flaming);)
The PN code is called psuedo-random since when one views the sequence it looks like a non-repeating sequence or noise if it is long enough and to observe the key one must see it before it is mixed with anything.
Hmm, so what is the count up to now for nuclear capable countries? All because someone like you thought it was right to share information and technological advances. At least you didn't make the mistake of saying that it is a right.
Re:The forbidden fruits of radio
on
GNU Radio
·
· Score: 0
800MHz - 900MHz Tuners
Given that cellular test equipment can still be marketed,
I'm not sure what the equipment-sale restrictions really forbid.
However, if this does become a popular way to eavesdrop on older
cellular networks, you can bet that 800-900MHz-capable pretuners
will be mandated off the market.
Anybody remember the old analog tuning dials on television
sets? Especially on the UHF nob? These use to tune up to
channel 83, but if you were to find a later model television set
before everything switched over
to cable ready tuners one
would find that the high UHF channels from at least channel 69
up to channel 83 had been eliminated from the dial.
The reason you ask? If one were to use the fine tuning dial (outer
ring) of the channel nob, one would be able to tune
in the AMPS cellular channels! But wait you say, are not AMPS
signals a type of FM modulation and analogue TV
signals are a type of AM modulation? You would be correct in this
thinking. There is a thing called slope detection though
and by slightly off tuning from the center frequency, one could
use an AM tuner to pick up and decode an FM signal.
Hence TV sets no longer (unless I am way off and my cheapo model
doesn't do it) will tune the high UHF broadcast
channels from around 69-83. See http://www.qrf.com/broadchs.htm
for a listing of on air broadcast channels in the US.
Re:Digital is *NOT* the way...
on
GNU Radio
·
· Score: 0
Digital is the way to go
Oh, and amateur radio enthusiasts have been homebrewing
radio gear for years... all analogue.
What's the advantage in using a DSP? And how do you get
rid of all the clock hash?
You must be one of those pro-cw freaks that thinks everyone
wanting to use a radio must use, or
at least know cw before obtaining an operator's license.
Amateur radio operators have also been homebrewing radio gear
for years in digital too. Have you
ever checked out TAPR (Tucson
Amateur Packet Radio) organization and their digital projects?
Or how about the DSP-10 project which is an SDR (software defined
radio) that can be built for
less than $400, operates in the VHF range, has a large user base,
and all source code/project plans
are freely attainable from http://www.proaxis.com/~boblark/dsp10.htm
Don't want to operate or listen in the VHF range. Build or
buy a transverter kit that can downconvert
or upconvert to the frequency range you need. This project is
perfect for that. People have already made
two way contacts with 150W or less and single yagi antennas at
each station by bouncing their signals off
of the moon. Before this type of hardware it use to take higher
power and a small antenna farm to make this
type of contact. These same people have gone back and made a second
contact with 5W and 10' dishes on
a higher frequency, again using the moon.
Want a SDR totally made for linux? Try Linrad.
The project leader gives very good instructions on setting up
linux and various software packages needed to support Linrad and
goes beyond by providing links to plans for
building A/D boards (analog-digital) and interfacing them with
the computer or plans for using your sound card
as the interface.
>>I like to wonder what a world without any significant source of 50/60 hertz 'hum' >>interference would be like, however. I think in some ways it'd be nicer.
And without power lines. Gotta love the idea of "free" power though with the transmission of wireless energy would we have higher rates of cancer now than we do with people living around HV AC transmission lines?
Definately a culture shock for me when I attended up there, being somewhat of an introvert. That changed pretty fast and I enjoyed the laid back and trusting attitude of the people there. Our house that I lived in and many of my friends' places were never locked and neither were our cars. Try doing that in Detroit, St. Louis, etc. Talk about a low crime rate!!
The negatives of living up there (there weren't too many) were no major cities close by. Marquette, MI was 1.5 hours, Sault Ste. Marie was 4 hours (?) and Green Bay, WI or Duluth, MN were 6 hours.
One of the neat things was hitting the radio scan button to find a radio station while travelling from Houghton, MI to Mackinaw City, MI. There were parts where the radio would continuously scan! At least one place the radio would do this was 90-100 miles long.
Sounds like American high tech workers are going to have to learn to say the word "eh?" a lot.
Well if you're an American high tech worker that graduated from MTU (Michigan Technological University) you won't have to learn. At least after spending 5 years there I sounded like the locals who all sound like canadians and northern Minnesotans (ever see Fargo?). The positive side of things is at least we didn't have flapping jaws and beady eyes.
Learn chinese. The US has pretty much forced
the rest of the world to learn English and
doesn't even require its own citizens to learn
other languages! Maybe this will force a change
once a half way decent portion of the chinese/asian population is on the internet.
Also, On the subject of line-of-site, check out the 900MHz radios. They don't require line of site and you can still get about 1Mb of bandwidth.
Um, what? Since when does 900MHz not require line of site? Being a UHF (some might say SHF) frequency it would most definately need line of site, some type of repeating system (like cell towers), or some propagation in effect which is very unreliable (ie meteor scatter, tropospheric scattering, temperature inversion, etc).
Anything 50MHz on up is line of site except with some type of repeating system or odd propagation/skip. And if you want BANDWIDTH then you need SHF frequencies above 2.4GHz and if you plan on sharing with everyone along the 45mile path then you'll want something running even higher around 10GHz or even more so that there is no noticeable bandwitdh drop except when people run quake/unreal servers;P~~
I would think that FDA jurisdiction is just like
it is down here. If you want to import it to
the US then you have to follow certain FDA
guidelines. Just like when US drug companies
want to export drugs to Europe or Canada they
have to obey those country's regulations on top
of what the FDA says. There is a standard that
most EU countries are starting to follow for
drug manufacturing which is ISO 14464. The
canucks have their own drug agency but I don't
recall what their name is. So it all boils down
to where the drug manufactured in space will be
headed to at the end of production.
Actually the tallest building is the one seen
in the movie "Entrapment" with Sean Connery. I
think it is located in Kuala Lampur. The rating
for tallest building status is done by usable
floor/office space. No one ever counts the towers on top of the roofs anymore or a couple of floors beneath due to radio frequency saturation (supposedly it causes cancer....).
Hmmm, co-op and high school students. Lets look
at the evidence here. No college degree in
engineering = no duties in the engineering
department except for monkey work. You should
be happy with what you're doing. As the above
author mentioned, there are plenty of fast food
jobs out there. You need the experience/education
before you can move up to a higher position. Once
you know how to test and troubleshoot the
equipment you'll have a basic idea of how the equipment works.
Now next time, if there is a next time, you co-op
you'll have a better chance of working in a
higher position such as installer;)
Slashdot Mirror
Not an explanation I have been given, but instead gave to someone of whom I later told it was a joke. An employee at the office I was working out of had to get his laptop on the network and it would not get an address. Well, the line was showing good to the tester but I went ahead and re-terminated it as a crossover instead. This ended up fixing the problem (the wall plate had been terminated wrong) but he was not in the office when I fixed it. I glanced behind his desk and there was a whole bundle of CAT5 back there, I pulled out a particular strand of it and when he came back in to ask the problem I told him the line was kinked and the electrons couldn't get through, just like a water hose when it is kinked. He bought it even though he use to be a service tech at an RF amplifier company! Couldn't stop laughing for half the day. I did tell him the real problem afterwards.
What's bad is even though Cingular may be fighting this, about 6 months ago they made the company I work for change all of its cellphone numbers from numbers that any of our offices could call with out dialing long distance to a single block of local numbers with the excuse that they were complying with the new number portability requirement set forward by the FCC.
My car has an ACV vavle :) (BTW, ACV is Air Control Valve)
Good ol' MTU alumni. While I was there (93-98) my roomies and I had a spud cannon building party. We used 4" (ID) combustion chambers that were about 1.5' long that reduced into 2" (ID), 4' long barrels. The end of the combustion chamber had a screw off lid for spraying in the propellant. We used apples, especially during deer season (Michigan people will understand that) and cheap hair spray (tried ether and WD-40). One of my roomies used a piezo igniter from a bbq grill and I used an old flash unit from a 110 camera. It was neat to hear mine whine as it charged up, then the light would come on and I used a nail inserted into one side to short out a large bolt on the other. The 300vdc coursing through that short was enough to burn my roomies arm when he decided to see if it would shock him and blow two chunks of metal off of a pocket knife blade.
:)
We would go behind DHH and fire off into the Portage Canal. We guesstimate that we could reach half way on a good day. The blue flame leaving the barrel in the middle of the night and echoes of the booms off the side of the "Ditch" rocked
First Post? Just had to try.
Anyways, as far as schools are concerned...Not sure in NYC.
I saw something like this back in 1998 or 1999 at Union Station in St. Louis. It was on the second floor by the rest of the arcade games. It had a fully enclosed cockpit that had a screen in it. The cockpit spun 360d on the arm it was mounted to which could also sping 360d with no chance of ever hitting the ground. Two people could ride it, it had a 500lb occupancy limit. While it was going, people could watch a monitor on the outside near the ride that showed what the people on the ride were seeing. It had a nice soundtrack that would play in the background along with all the normal rollercoaster sounds and as it went through the ride you'd hear the occupants screaming and change falling out of their pockets just like on a regular coaster. Unfortunately I never saw who the manufacturer was but maybe someone else on here from St. Louis may have also seen it before?
Anybody see the independent movie PI? The mathematician's "super computer" gets infested with ants in the beginning and prompts him to make a deal with someone for the best chip out there in return for research into the magic number (sort of like the unified theory but different).
Hmm, I'm not sure where you are getting your salary statistics. When I reviewed the starting salaries, back in '98, upon graduation from the university that I attended it revealed that female starting salaries in most engineering fields were slightly higher than that of new male hires. Notice I said most engineeing fields. There were still a few engineering fields that salaries were significantly higher.
First off, isn't the 2.4GHz band an ISM band? Meaning that there are also medical devices that operate and are prone to receiving interference in this band. It would be hard to believe that something like this is targetted at hospitals. I've done RF interference testing on medical and lab instruments. Generally we did tests with anything that created RF like the maintenance walkie talkies that transmitted in the VHF/UHF range at about 5W output. We would test with radio keyed at the case of the instrument, 6" away, 1' away, 3' away, 10' away and if it still caused some type of malfunctions in the instrument under test we would keep moving further away until it stopped interfering.
Also, in clean rooms such as ER (I've never been in ER but I've been in other clean rooms down to a Class 100), they use a flush mounted phone that has a flat, cleanable face with no holes in it that can not only be dialled out on, but also has a programmable memory for speed dialling.
Just FYI
If the companies are monitoring for so called cyberslacking it
may not matter much if you are using SSL/SSH with your instant
messaging. There is software for monitoring the users' desktops
and keystrokes which is one of many tools that employers can use,
not only packet/traffic monitoring on company networks. Just to
add another formula to things, monitoring can be completely seperate
from the computer, they (employers) can also use well placed CCTV
systems.
I'm also an amateur licensed operator and I have to disagree. The only time that spread spectrum use in the amateur allocations would have a possibility of interfering would be for the weak signal guys such as the ones that bounce their signals off the moon. Interference for storm chasing or repeater operation, both of which are done on FM, would not be noticed even though the noise floor would be raised (only marginally) since all you would do would be to turn the squelch up or turn on a code squelch such as Motorola's PL (CTCSS in amateur radio) tones. http://www.tapr.org for more info.
Of course you didn't look at any of the spectrum above 20GHz? Is
this because of cost/feasibility or just information available to
you? Above 300GHz nothing is licensed. Of course once one reaches
a high enough power level regulations come into play like with lasers
which are in the THz(?) range.
Unfortunately on the lower frequencies they cannot be attached to
the land beneath the expected coverage because of propagation issues
which may cause interference in another cell or plot of land. Once
one reaches a high enough frequency (above the 300GHz range, again
possibly in the THz range) it can be land area specific because of
specific attenuation by the atmosphere. This could then be used
to create thousands/millions of tiny cells with a very large amount
of bandwidth, since bandwidth available ultimately increases with
frequency, that would not cause intereference with each other because
they would be land area specific.
DSSS or Direct Sequence Spread Spectrum. Without getting too ;)
technical a psuedo-random noise code or PN code is used. The
information is mixed with the PN and then 'spread'. When the signal
is received, the PN the receiver has is compared to the PN in the
spread signal. If they are the same, the PN is subtracted from the
signal and you have your information back. If the PN codes are
different then the signal is just noise hence being able to have more
than one transmitter in a given bandwidth. Now keep in mind this is
really generallized (for those EE's that feel like flaming)
The PN code is called psuedo-random since when one views the
sequence it looks like a non-repeating sequence or noise if it is
long enough and to observe the key one must see it before it is
mixed with anything.
Hmm, so what is the count up to now for nuclear capable countries?
All because someone like you thought it was right to share
information and technological advances. At least you didn't
make the mistake of saying that it is a right.
Given that cellular test equipment can still be marketed, I'm not sure what the equipment-sale restrictions really forbid. However, if this does become a popular way to eavesdrop on older cellular networks, you can bet that 800-900MHz-capable pretuners will be mandated off the market.
Anybody remember the old analog tuning dials on television sets? Especially on the UHF nob? These use to tune up to
channel 83, but if you were to find a later model television set before everything switched over to cable ready tuners one
would find that the high UHF channels from at least channel 69 up to channel 83 had been eliminated from the dial.
The reason you ask? If one were to use the fine tuning dial (outer ring) of the channel nob, one would be able to tune
in the AMPS cellular channels! But wait you say, are not AMPS signals a type of FM modulation and analogue TV
signals are a type of AM modulation? You would be correct in this thinking. There is a thing called slope detection though
and by slightly off tuning from the center frequency, one could use an AM tuner to pick up and decode an FM signal.
Hence TV sets no longer (unless I am way off and my cheapo model doesn't do it) will tune the high UHF broadcast
channels from around 69-83. See http://www.qrf.com/broadchs.htm for a listing of on air broadcast channels in the US.
Oh, and amateur radio enthusiasts have been homebrewing radio gear for years... all analogue.
What's the advantage in using a DSP? And how do you get rid of all the clock hash?
You must be one of those pro-cw freaks that thinks everyone wanting to use a radio must use, or
at least know cw before obtaining an operator's license.
Amateur radio operators have also been homebrewing radio gear for years in digital too. Have you
ever checked out TAPR (Tucson Amateur Packet Radio) organization and their digital projects?
Or how about the DSP-10 project which is an SDR (software defined radio) that can be built for
less than $400, operates in the VHF range, has a large user base, and all source code/project plans
are freely attainable from http://www.proaxis.com/~boblark/dsp10.htm
Don't want to operate or listen in the VHF range. Build or buy a transverter kit that can downconvert
or upconvert to the frequency range you need. This project is perfect for that. People have already made
two way contacts with 150W or less and single yagi antennas at each station by bouncing their signals off
of the moon. Before this type of hardware it use to take higher power and a small antenna farm to make this
type of contact. These same people have gone back and made a second contact with 5W and 10' dishes on
a higher frequency, again using the moon.
Want a SDR totally made for linux? Try Linrad. The project leader gives very good instructions on setting up
linux and various software packages needed to support Linrad and goes beyond by providing links to plans for
building A/D boards (analog-digital) and interfacing them with the computer or plans for using your sound card
as the interface.
>>I like to wonder what a world without any significant source of 50/60 hertz 'hum'
>>interference would be like, however. I think in some ways it'd be nicer.
And without power lines. Gotta love the idea of "free" power though with the transmission of
wireless energy would we have higher rates of cancer now than we do with people living around
HV AC transmission lines?
The negatives of living up there (there weren't too many) were no major cities close by. Marquette, MI was 1.5 hours, Sault Ste. Marie was 4 hours (?) and Green Bay, WI or Duluth, MN were 6 hours.
One of the neat things was hitting the radio scan button to find a radio station while travelling from Houghton, MI to Mackinaw City, MI. There were parts where the radio would continuously scan! At least one place the radio would do this was 90-100 miles long.
Anyways, a bit off topic ;)
Well if you're an American high tech worker that graduated from MTU (Michigan Technological University) you won't have to learn. At least after spending 5 years there I sounded like the locals who all sound like canadians and northern Minnesotans (ever see Fargo?). The positive side of things is at least we didn't have flapping jaws and beady eyes.
"Say ya to da UP, eh!"
Learn chinese. The US has pretty much forced
the rest of the world to learn English and
doesn't even require its own citizens to learn
other languages! Maybe this will force a change
once a half way decent portion of the chinese/asian population is on the internet.
Also, On the subject of line-of-site, check out the 900MHz radios. They don't require line of site and you can still get about 1Mb of bandwidth.
;P~~
Um, what? Since when does 900MHz not require line of site? Being a UHF (some might say SHF) frequency it would most definately need line of site, some type of repeating system (like cell towers), or some propagation in effect which is very unreliable (ie meteor scatter, tropospheric scattering, temperature inversion, etc). Anything 50MHz on up is line of site except with some type of repeating system or odd propagation/skip. And if you want BANDWIDTH then you need SHF frequencies above 2.4GHz and if you plan on sharing with everyone along the 45mile path then you'll want something running even higher around 10GHz or even more so that there is no noticeable bandwitdh drop except when people run quake/unreal servers
just had to say it....I see your schwartz is as :)
big as mine.
I would think that FDA jurisdiction is just like
it is down here. If you want to import it to
the US then you have to follow certain FDA
guidelines. Just like when US drug companies
want to export drugs to Europe or Canada they
have to obey those country's regulations on top
of what the FDA says. There is a standard that
most EU countries are starting to follow for
drug manufacturing which is ISO 14464. The
canucks have their own drug agency but I don't
recall what their name is. So it all boils down
to where the drug manufactured in space will be
headed to at the end of production.
Actually the tallest building is the one seen
in the movie "Entrapment" with Sean Connery. I
think it is located in Kuala Lampur. The rating
for tallest building status is done by usable
floor/office space. No one ever counts the towers on top of the roofs anymore or a couple of floors beneath due to radio frequency saturation (supposedly it causes cancer....).
Hmmm, co-op and high school students. Lets look ;)
at the evidence here. No college degree in
engineering = no duties in the engineering
department except for monkey work. You should
be happy with what you're doing. As the above
author mentioned, there are plenty of fast food
jobs out there. You need the experience/education
before you can move up to a higher position. Once
you know how to test and troubleshoot the
equipment you'll have a basic idea of how the equipment works.
Now next time, if there is a next time, you co-op
you'll have a better chance of working in a
higher position such as installer