And of course, modern day high-reliability phone systems (in mines, etc) now use optical fiber (and local batteries) precisely because the most common point of failure is in the line itself (frequently caused by electrolysis).
This is actually a liability. Having 50V DC on the pair dramatically increases the risk of corrosion and failure.
The original "magneto" phone system used dry batteries locally to power the phone. These only needed changing every few years. High reliability phone systems (in mines etc) still do it this way. The military use voice powered phones (no batteries at all).
If we wanted to, it would be trivial to avoid sending power over the phone lines. A long life battery pack, perhaps with a small solar panel would be sufficient.
As you say, it must be me, but I find it much easier to send an email.
I can send or receive messages at a convenient time, can give more thought to the form and detail, can edit mistakes, can easily include necessary attachments and will always have an exact record.
I don't have a landline and rarely carry a mobile. My recorded message gives my email address and asks people to use it.
The whole point of training as an artist is to acquire the art of "seeing" the subject.
To a normal person the action of the eye (focus, colour balance, brightness compensation) is invisible and transparent. But a trained artist learns to incorporate the effect of the eye's processing into his painting. Some do it instinctively, some use photographic aids.
Many early artists used a camera obscura and/or mirrors to help them "see" the subject when creating the first draft of a painting. These days an artist will often use a colour photograph for the same purpose.
> The noise floor across the whole of the RF spectrum is rising by an average of 1db a year.
You are correct, but not for the reasons you discussed. If the millions of Transmitters were clean and well designed, they would not cause RF interference to other users (except where they were sharing common frequencies).
The problem is that much of the electronics junk generate spurious harmonics. Plasma TV's, PC's, BPL, etc. all put out a horrendous range of broadband rubbish.
This is compounded by many manufacturers and importers ignoring the existing EMC standards, as well as the corrupt regulatory bodies (FCC etc) turning a blind eye to the cheap plastic junk being imported.
Just one specific example. Once upon a time, manufactures used linear-mode power supplies with large transformers. In an effort to reduce costs, they have universally changed to using switch-mode supplies. These supplies are certainly cheaper, but they almost always generate much higher levels of radio interference.
There's a trade-off: Being able to buy cheap electronics means that there's a good chance you will be unable to enjoy it due to the resulting interference levels.
This is an old idea. Houses in the North West of Australia have been built using an inner safety core for at least 35 years. I know, I've lived in one.
The article says right there in the heading ".. so it's easy to track many of the brighter stars as well as planets and deep-space probes, such as Voyagers 1 and 2"
Also there's a big difference between tracking and locking-on. Most big systems (eg NASA) simply track the target (based on precise ephemerals) because extracting the signal from the noise (post processing) takes far to long for locking-on to be practical.
Plus the beam-width of even a huge dish is far to wide to allow locking-on to be of much advantage. You can nod the dish a little and extract revised ephemerals after the event, but that's about all.
> I'd like to know how a chat room worked on a telegraph.
On most Telegraph lines there were many operators spaced at intervals along the line and its branch lines. So when there was no traffic to send, the bored operators would chat.
And of course there were many amateur telegraph circuits, some connecting dozens of enthusiasts in a town or suburb.
> It occurs to me that if the signals have almost no chance of reaching China
As you say it would be trivial for the manufacturer to build a WWVB test generator,
however there are multiple alternatives to WWVB around the world. Many clock chips can switch to an alternative signal if WWVB isn't audible. http://www.cl.cam.ac.uk/~mgk25/time/lf-clocks/
FWIW, I can hear WWVB in Australia, although I do need an outside antenna.
> . I really don't understand the slow uptake to 7
Win7 has its advantages (more memory, multiprocessor, etc), but it's lousy with aggravating and stupid little bugs.
If only M/S listened to and valued it's client's feedback.
M/S had WinXP sorted out pretty well. It's infuriating when you upgrade and find that all the nice things have been plain forgotten. Or screwed up totally, like the File Manager and the Search function.
Once again the hams have been doing this for ever.
Imagine a radio class where people are earning Morse Code. Copying data sent as audio from a buzzer.
Or all the umpteen sound card communication applications like PSK31.
A standard source of fun at Ham meets is to have a PSK31 "scramble" where a bunch of people use their laptops to communicate simultaneously via PSK31 and audio.
> The point of emoticons are that they are simple ASCII text
And they date back even further. The Ascii ones were derived from the various Teleprinter emoticons (Baudot code, etc), which in turn came from the Morse equivalents ("HI" for hilarity, 73, 88, etc).
The "boom boom" used in comedy shows, possibly came from the "dit dit" used by Morse operators for exactly the same purpose.
No doubt bored Semaphore operators invented their own variations as well.
Slashdot Mirror
Been using them in Oz for years...
And of course, modern day high-reliability phone systems (in mines, etc) now use optical fiber (and local batteries) precisely because the most common point of failure is in the line itself (frequently caused by electrolysis).
> Yes, but the network powers the phone.
This is actually a liability. Having 50V DC on the pair dramatically increases the risk of corrosion and failure.
The original "magneto" phone system used dry batteries locally to power the phone. These only needed changing every few years.
High reliability phone systems (in mines etc) still do it this way. The military use voice powered phones (no batteries at all).
If we wanted to, it would be trivial to avoid sending power over the phone lines.
A long life battery pack, perhaps with a small solar panel would be sufficient.
You used the words "big" and "generator".
With good design, a battery bank and a modest solar array should be sufficient.
Solar powered Cell Sites are common world wide.
As you say, it must be me, but I find it much easier to send an email.
I can send or receive messages at a convenient time, can give more thought to the form and detail, can edit mistakes, can easily include necessary attachments and will always have an exact record.
I don't have a landline and rarely carry a mobile. My recorded message gives my email address and asks people to use it.
This is a ridiculous article.
The whole point of training as an artist is to acquire the art of "seeing" the subject.
To a normal person the action of the eye (focus, colour balance, brightness compensation) is invisible and transparent.
But a trained artist learns to incorporate the effect of the eye's processing into his painting.
Some do it instinctively, some use photographic aids.
Many early artists used a camera obscura and/or mirrors to help them "see" the subject when creating the first draft of a painting.
These days an artist will often use a colour photograph for the same purpose.
> With your level of expertise and experience, you should consider starting your own business.
And you know what percentage of new business survive?
This is part two of the "American Dream"
Sadly your experience is common. The older you get, the harder it is to find work.
So in your last decade or so, instead of saving for your retirement, you end up chewing through what little savings you have,
It's called the "American Dream".
I'm not sure about the Tesla batteries, but most rechargeable batteries need an "over charge" to get to 100% full.
If the charger stops at the "full" mark (as indicated by Volts or A/H's) the batteries will be only be at about 80% full.
> The noise floor across the whole of the RF spectrum is rising by an average of 1db a year.
You are correct, but not for the reasons you discussed. If the millions of Transmitters were clean and well designed, they would not cause RF interference to other users (except where they were sharing common frequencies).
The problem is that much of the electronics junk generate spurious harmonics. Plasma TV's, PC's, BPL, etc. all put out a horrendous range of broadband rubbish.
This is compounded by many manufacturers and importers ignoring the existing EMC standards, as well as the corrupt regulatory bodies (FCC etc) turning a blind eye to the cheap plastic junk being imported.
Just one specific example. Once upon a time, manufactures used linear-mode power supplies with large transformers. In an effort to reduce costs, they have universally changed to using switch-mode supplies. These supplies are certainly cheaper, but they almost always generate much higher levels of radio interference.
There's a trade-off: Being able to buy cheap electronics means that there's a good chance you will be unable to enjoy it due to the resulting interference levels.
This is an old idea.
Houses in the North West of Australia have been built using an inner safety core for at least 35 years.
I know, I've lived in one.
> This isn't as much tracking them in the sense of figuring out where they are, but rather tracking them by controlling a dish.
Idiot. Of course the Hams are automatically steering their Satellite dishes. What on earth do you think they are doing?
It's tragic how some computer geeks live in a bubble hermetically sealed from the rest of the scientific world.
The article says right there in the heading ".. so it's easy to track many of the brighter stars as well as planets and deep-space probes, such as Voyagers 1 and 2"
Also there's a big difference between tracking and locking-on. Most big systems (eg NASA) simply track the target (based on precise ephemerals) because extracting the signal from the noise (post processing) takes far to long for locking-on to be practical.
Plus the beam-width of even a huge dish is far to wide to allow locking-on to be of much advantage. You can nod the dish a little and extract revised ephemerals after the event, but that's about all.
Amateur Radio operators have been automatically tracking satellites for decades and the tracking ephemeral's have been published forever.
Searching Google for "amateur satellite tracking" gets around 10 pages of hits.
Never mind. This is Slash Dot...
Who needs encryption keys or back doors if Redmont is handing over (and not patching) Zero Day Exploits?
> I'd like to know how a chat room worked on a telegraph.
On most Telegraph lines there were many operators spaced at intervals along the line and its branch lines.
So when there was no traffic to send, the bored operators would chat.
And of course there were many amateur telegraph circuits, some connecting dozens of enthusiasts in a town or suburb.
And then of course Amateur Radio came along.
> It occurs to me that if the signals have almost no chance of reaching China
As you say it would be trivial for the manufacturer to build a WWVB test generator,
however there are multiple alternatives to WWVB around the world.
Many clock chips can switch to an alternative signal if WWVB isn't audible.
http://www.cl.cam.ac.uk/~mgk25/time/lf-clocks/
FWIW, I can hear WWVB in Australia, although I do need an outside antenna.
> . I really don't understand the slow uptake to 7
Win7 has its advantages (more memory, multiprocessor, etc), but it's lousy with aggravating and stupid little bugs.
If only M/S listened to and valued it's client's feedback.
M/S had WinXP sorted out pretty well. It's infuriating when you upgrade and find that all the nice things have been plain forgotten.
Or screwed up totally, like the File Manager and the Search function.
If only Microsoft would encourage feedback from uses, and act on them.
I have collected a long list of bugs and annoyances with Win7 which I really wish that M/S was interested in.
Where to send my list to?
arrogant, tick
fanboy, tick
you illustrate my point exactly
Ubermix sounds like a great idea. But on my first look I see Incomprehensible Icons and Icon names.
Celestia (Gnome) ?
Klavaro ?
GeoGebra ?
This arrogant nonsense will drive many away. The problem with Linux is that you have to be a LInux fanboy to understand it.
Why not use simple and descriptive language?
Once again the hams have been doing this for ever.
Imagine a radio class where people are earning Morse Code. Copying data sent as audio from a buzzer.
Or all the umpteen sound card communication applications like PSK31.
A standard source of fun at Ham meets is to have a PSK31 "scramble" where a bunch of people use their laptops to communicate simultaneously via PSK31 and audio.
And a hundred other examples I could think of.
How long before all RC helicopters (and all hobby RC planes for that matter) will be banned ?
> The point of emoticons are that they are simple ASCII text
And they date back even further. The Ascii ones were derived from the various Teleprinter emoticons (Baudot code, etc),
which in turn came from the Morse equivalents ("HI" for hilarity, 73, 88, etc).
The "boom boom" used in comedy shows, possibly came from the "dit dit" used by Morse operators for exactly the same purpose.
No doubt bored Semaphore operators invented their own variations as well.
I'm always puzzled why people demonise old cars and their drivers (unless you sell new cars, of course).
If you can keep an older car on the road, it's probably because you (1) travel relatively low mileage and/or (2) you keep the car in good condition.
Failing the above, you are driving an old wreck into the ground, so it won't be around for very long anyway.
Whatever, there's little point in penalising someone who drives an older car.