Must admit, the technology is awesome. Who would have thought it possible a
few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get the
technology so refined that we could mass produce such a convoluted way of
giving a colour picture of the quality we ended up getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube to
excite a phosphor dot - Ah Ah Ah!"

"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it possible
a
few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get the
technology so refined that we could mass produce such a convoluted way of
giving a colour picture of the quality we ended up getting.

by taking advantage of the fact that the picture is "moving" to trick the
eye into thinking it is better than it really is

tim

"tim....." wrote in message
...

"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it possible
a
few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get the
technology so refined that we could mass produce such a convoluted way of
giving a colour picture of the quality we ended up getting.

by taking advantage of the fact that the picture is "moving" to trick the
eye into thinking it is better than it really is

There are two separate issues:

1. manufacturing a CRT with sufficient precision that the holes in the
shadow mask exactly line up with the phosphor dots as "seen" by electrons
travelling in a straight line between the anode and phosphor, for a variety
of vertical and horizontal deflection angles

2. squeezing the colour information into the same bandwidth as existing B&W
info (PAL, SECAM or NTSC encoding)


(1) is mainly manufacturing tolerances and linearity of electronic control
signals (focus, beam deflection).

(2) is the really amazing one: the use of a colour sub-carrier that causes
the spectrum of the colour information (which mainly occurs at multiples of
the line rate) to interleave with that of the luminance signal (which has a
similar spectrum) by use of f(sc) = (f(line)+1)/2, together with vestigial
sideband AM to give full colour bandwidth for one sideband and
low-pass-filtered sideband on the other. Making sure that none of the
newly-introduced signals interfere with the existing luminance signals, so
choose a sub carrier that causes a dot pattern that moves rather than being
stationary (to make it less noticeable). And then using quadrature
modulation so the U and V signals are modulated about the same carrier but
don't interfere with each other.

And then we have the PAL improvements over NTSC to prevent phase errors
manifesting themselves as shifts in hue (they only cause error in saturation
which is much less notceable).



But then we get onto the encoding of digital TV signals into interleaved
MPEG streams, COFDM encoding, pseudo-random encoding to make the digital
signal look like noise with no discernable pattern when received on an
analogue TV (that factor is no longer needed!). I wonder how big a DTV
receiver would be if it had to be constructed with discrete transistors,
resistors and capacitors, without the benefit of integrated circuits.

On your last point I can only point you to what happens if, of example even
a computer from the 1980s logic arrays are simulated by ordinary logic chips
of the time the resulting pcb would no longer fit in the box.
Another example was good old fashioned teletext of the old sort.
The first boards made were huge crammed with chips. Pye Labgear made an
adaptor just for teletext in the early days. As it also contained a tv
minus the display, it was as big as an early video, and the tifax decoder
made by Texas Instruments was more than a foot square crammed with chips
and took a lot of current.
However only five years on and the whole thing was in one tiny chip fitted
inside most tvs.
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"NY" wrote in message
o.uk...
"tim....." wrote in message
...

"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it
possible a
few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get
the
technology so refined that we could mass produce such a convoluted way
of
giving a colour picture of the quality we ended up getting.

by taking advantage of the fact that the picture is "moving" to trick the
eye into thinking it is better than it really is

There are two separate issues:

1. manufacturing a CRT with sufficient precision that the holes in the
shadow mask exactly line up with the phosphor dots as "seen" by electrons
travelling in a straight line between the anode and phosphor, for a
variety of vertical and horizontal deflection angles

2. squeezing the colour information into the same bandwidth as existing
B&W info (PAL, SECAM or NTSC encoding)


(1) is mainly manufacturing tolerances and linearity of electronic control
signals (focus, beam deflection).

(2) is the really amazing one: the use of a colour sub-carrier that causes
the spectrum of the colour information (which mainly occurs at multiples
of the line rate) to interleave with that of the luminance signal (which
has a similar spectrum) by use of f(sc) = (f(line)+1)/2, together with
vestigial sideband AM to give full colour bandwidth for one sideband and
low-pass-filtered sideband on the other. Making sure that none of the
newly-introduced signals interfere with the existing luminance signals, so
choose a sub carrier that causes a dot pattern that moves rather than
being stationary (to make it less noticeable). And then using quadrature
modulation so the U and V signals are modulated about the same carrier but
don't interfere with each other.

And then we have the PAL improvements over NTSC to prevent phase errors
manifesting themselves as shifts in hue (they only cause error in
saturation which is much less notceable).



But then we get onto the encoding of digital TV signals into interleaved
MPEG streams, COFDM encoding, pseudo-random encoding to make the digital
signal look like noise with no discernable pattern when received on an
analogue TV (that factor is no longer needed!). I wonder how big a DTV
receiver would be if it had to be constructed with discrete transistors,
resistors and capacitors, without the benefit of integrated circuits.

"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it possible
a
few years ago.


Those hoverboards would be more awesome if they actually hovered:-)


--
Adam

Yes but the idea is a good one.
I do feel though that all of those devices are a bit dangerous in crowds
and indeed around us blind folk. they are actually illegal and of course if
you have an accident in one you are not covered by any insurance either.
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"ARW" wrote in message
...
"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it possible
a
few years ago.


Those hoverboards would be more awesome if they actually hovered:-)


--
Adam

In article ,
"Brian-Gaff" writes:
Yes but the idea is a good one.
I do feel though that all of those devices are a bit dangerous in crowds
and indeed around us blind folk. they are actually illegal and of course if
you have an accident in one you are not covered by any insurance either.

A 15 year old boy died this week when his hoverboard took him in front
of a moving bus in London.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Today apparently shoplifters are using the hoverboards to help them nick
stuff fast. Trouble is the less expert people usually end up in a big heap
on the ground with a big security guard looking down at them in that way
they have that indicates You stupid boy...
as for crts, it was gradual. Remember the basic cathode ray tube, love the
oldfasioned name, was very old indeed, but the colour system was I believe
invented by some RCA bloke one day, who realised that the shadow masked
itself could be used to indicate where the phospher dots needed to go. It
was done photographically I believe.
Very power wasteful though when you consider a lot of the beam is obscured
on each gun.
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"DerbyBorn" wrote in message
2.222...
Must admit, the technology is awesome. Who would have thought it possible
a
few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get the
technology so refined that we could mass produce such a convoluted way of
giving a colour picture of the quality we ended up getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube to
excite a phosphor dot - Ah Ah Ah!"

On 11/12/2015 19:58, Brian-Gaff wrote:
Today apparently shoplifters are using the hoverboards to help them nick
stuff fast. Trouble is the less expert people usually end up in a big heap
on the ground with a big security guard looking down at them in that way
they have that indicates You stupid boy...
as for crts, it was gradual. Remember the basic cathode ray tube, love the
oldfasioned name, was very old indeed, but the colour system was I believe
invented by some RCA bloke one day, who realised that the shadow masked
itself could be used to indicate where the phospher dots needed to go. It
was done photographically I believe.
Very power wasteful though when you consider a lot of the beam is obscured
on each gun.
Brian

Especially the Delta guns where 90% of the power ended up heating the
shadow mask. Some were made of Invar to reduce distortion.

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we get
the technology so refined that we could mass produce such a convoluted
way of giving a colour picture of the quality we ended up getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube to
excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

"pamela" wrote in message
...
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

My grandad had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
and one of these -
http://www.radiomuseum.org/images/ra...yle_121807.jpg
which he transported around local pubs in a pram.
He also had a - http://www.richardsradios.co.uk/Images/dac11.jpg
The last 2 I still have along with ~2 dozen cylinder records - under the old
apple tree/edison bell records etc
My 8 year old grandson can't believe we were so "Flintstone".
Lets face it, when something is developed, by definition, it's already out
of date.

In article om, bm
writes

"pamela" wrote in message
...
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

My grandad had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
and one of these -
http://www.radiomuseum.org/images/ra...c/phonograph_h
ome_a_late_new_style_121807.jpg
which he transported around local pubs in a pram.
He also had a - http://www.richardsradios.co.uk/Images/dac11.jpg
The last 2 I still have along with ~2 dozen cylinder records - under the old
apple tree/edison bell records etc
My 8 year old grandson can't believe we were so "Flintstone".
Lets face it, when something is developed, by definition, it's already out
of date.


New fangled kit. It'll never catch on
We had one of these at home. My brother has it now.
http://i.luxury-insider.com/uploads/...-selection-ant
ique-polyphone-no-5-1.jpg?width=650
--
bert

"bert" wrote in message
...
In article om, bm
writes

"pamela" wrote in message
...
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

My grandad had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
and one of these -
http://www.radiomuseum.org/images/ra...c/phonograph_h
ome_a_late_new_style_121807.jpg
which he transported around local pubs in a pram.
He also had a - http://www.richardsradios.co.uk/Images/dac11.jpg
The last 2 I still have along with ~2 dozen cylinder records - under the
old
apple tree/edison bell records etc
My 8 year old grandson can't believe we were so "Flintstone".
Lets face it, when something is developed, by definition, it's already out
of date.


New fangled kit. It'll never catch on
We had one of these at home. My brother has it now.
http://i.luxury-insider.com/uploads/...-selection-ant
ique-polyphone-no-5-1.jpg?width=650

That is terrific.

pamela wrote:
On 14:30 14 Dec 2015, bert wrote:

In article om, bm
writes

"pamela" wrote in message
...
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended
up getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass
tube to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves
themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal
set into a 15 year old relative of mine. I may as well have been
talking Chinese. He simply couldn't understand why anyone wouldn't
use their smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show
real interest. Or maybe not? Tell me.

My grandad had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
and one of these -
http://www.radiomuseum.org/images/ra...nc/phonograph_
h ome_a_late_new_style_121807.jpg
which he transported around local pubs in a pram.
He also had a - http://www.richardsradios.co.uk/Images/dac11.jpg
The last 2 I still have along with ~2 dozen cylinder records - under
the old apple tree/edison bell records etc
My 8 year old grandson can't believe we were so "Flintstone".
Lets face it, when something is developed, by definition, it's already
out of date.


New fangled kit. It'll never catch on
We had one of these at home. My brother has it now.

http://i.luxury-insider.com/uploads/...06/Audiophile-
selection-ant ique-polyphone-no-5-1.jpg?width=650

That's utterly gorgeous. How marvellous. Must be worth a fortune.


You should visit the Yew Tree inn in Cauldon Low. Got lots of stuff like
this.

http://www.yewtreeinncauldon.com

Tim

"pamela" wrote in message
...
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of curiousity.

I bet he's in the majority with kids that age.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

Without actually trying it I'd be prepared to be that
it would be hard to find many that age who would
show real interest.

When I was that age I likely would have had the
same reaction if someone had told me how much
harder it was before shops had been invented etc
except with the most skilful people trying to get
me to consider that question.

It would have been easier to try to get across how
different it would have been to have household
slaves etc, particularly if they had suggested how
much more convenient it would have been to be
able to **** any slave you felt like ****ing etc |-)

In message , pamela
writes

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

Difficult. I think school has an influence, but we're lucky. Son
attends a rural Comprehensive in NE Scotland, with one non white face,
everyone speaks English (or Scottish!) as their first language and class
sizes are small (20). His science classes are Graphics, Biology and
Engineering Science. Biology will be dropped next year, but he hopes to
take the other two to 0 level equivalent. I was delighted to find
graphics is not all CAD. They are using drawing boards - what I would
call Technical Drawing. He has built a small circuit board and can
solder. We discuss things like gears and torque. I keep meaning to dig
out some Meccano for a practical demonstration :-)

I don't think he is as inquisitive as I was at that age, but I do think
his inquisitiveness is increasing, partly with age, partly with the
range of subjects discussed at school, and partly because of his father.
He is 14 and I'm an old fart of 63, and, at his age, I enjoyed Philips
Electronic Engineer sets in which he has shown little interest. I still
have the remains of my old crystal set in the shed. Must dig it out and
show him.
--
Graeme

On 12/12/2015 17:21, pamela wrote:
With luck one day he will graduate to those iPhone teardowns which examine
the components used. I like them.

http://www.techinsights.com/teardown...pple-iphone-6/

First thing I see is a power amplifier module. Not exactly a single part.

I've worked on 'phone chips, and I don't understand a lot of them. I
understood a crystal radio, and I remember having an old Grundig
FM/LW/MW/SW radio with a circuit diagram that I could understand. These
days? No chance.

Andy

In message , pamela
writes
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

I'm sure not all kids were all that bothered about crystal radios 50
years ago either, different things float peoples boats. We are a bit of
a self selecting demographic on uk.d-i-y I suspect.

Also, there is the wider context. We are much less likely to be fixing
things at home nowadays, so there is much less of a culture of tinkering
with things and kids are much less likely to be exposed to it.. I think
there is also something about the distance between the technology you
can fiddle with and the technology around you. Maybe a crystal radio is
to far divorced from the world of smartphones, to seem of any
relevance, unless you have an interest it that sort of thing.

TBH I doubt that either of our daughters (11 and 14) would be that
interested in a crystal radio. Even though they are both fairly
technically minded. (I helped the 14yo fix her phone the other day and
the 11yo loves fiddling with things, making stuff etc.)
--
Chris French

"Chris French" wrote in message
...
In message , pamela
writes
On 22:55 11 Dec 2015, Tim+ wrote:

pamela wrote:
On 13:53 11 Dec 2015, DerbyBorn wrote:

Must admit, the technology is awesome. Who would have thought it
possible a few years ago.


Another thing I find amazing - CRT Colour TV. How on earth did we
get the technology so refined that we could mass produce such a
convoluted way of giving a colour picture of the quality we ended up
getting.

"Cue Cadbury Smash Aliens "Aim and electron beam down a glass tube
to excite a phosphor dot - Ah Ah Ah!"

Never mind tellys, I still marvel at the very radio waves themselves!

As for a crystal set, I find it's so wonderful in its sheer
simplicity.

Nearer to magic than science! Loved making them as a kid.

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

I'm sure not all kids were all that bothered about crystal radios 50 years
ago either,

I know they weren't, and 55 years ago either, very
few of those I knew at that time were, even tho I was.

different things float peoples boats.

Indeed.

We are a bit of a self selecting demographic on uk.d-i-y I suspect.

Indeed.

Also, there is the wider context. We are much less likely to be fixing
things at home nowadays,

Not sure that is true with renos. My parents were into it
when I was a kid, but not many other parents of the kids
I knew at that time were. Lot more were into renos etc in
say the 70s later than that.

so there is much less of a culture of tinkering with things and kids are
much less likely to be exposed to it..

Its more done in other areas like Minecraft etc now.

I think there is also something about the distance between the technology
you can fiddle with and the technology around you.

Less in some ways with stuff like Minecraft.

Maybe a crystal radio is to far divorced from the world of smartphones,
to seem of any relevance, unless you have an interest it that sort of
thing.

True.

TBH I doubt that either of our daughters (11 and 14) would be that
interested in a crystal radio. Even though they are both fairly
technically minded. (I helped the 14yo fix her phone the other day and the
11yo loves fiddling with things, making stuff etc.)

I've just spent the last couple of hours helping a kid that has
left school relatively recent and now has a wife and 3.5 year
old do some basic stuff with the first car he has owned rather
than using one close to exclusively that his dad owned.

In article ,
Chris French writes:
I'm sure not all kids were all that bothered about crystal radios 50
years ago either, different things float peoples boats. We are a bit of
a self selecting demographic on uk.d-i-y I suspect.

Also, there is the wider context. We are much less likely to be fixing
things at home nowadays, so there is much less of a culture of tinkering
with things and kids are much less likely to be exposed to it.. I think
there is also something about the distance between the technology you
can fiddle with and the technology around you. Maybe a crystal radio is
to far divorced from the world of smartphones, to seem of any
relevance, unless you have an interest it that sort of thing.

TBH I doubt that either of our daughters (11 and 14) would be that
interested in a crystal radio. Even though they are both fairly
technically minded. (I helped the 14yo fix her phone the other day and
the 11yo loves fiddling with things, making stuff etc.)

I was staying in the spare room at my parents a couple of weeks ago,
having taken the niece and nephew there for the weekend. In the
bookcase were a few of my old Ladybird books, including the one on
building a transistor radio. Finding an OC70 might be hard today, but
it could be updated to use silicon transistors. I did wonder how much
longer there would be any AM radio signal which can be detected with
just a diode.

I did build some of it as a child. However, I'd already managed to
repurpose an old intermediate frequency transformer into a tuned circuit
to pick up Radio 4 using an aerial wire the length of my bedroom, which
could power a crystal earpice from the aerial power alone. Spent ages
in bed listening to it when I should have been asleep ;-)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 12 Dec 2015 09:32:35 +0000, Chris French
wrote:


I'm sure not all kids were all that bothered about crystal radios 50
years ago either, different things float peoples boats. We are a bit of
a self selecting demographic on uk.d-i-y I suspect.


I think there is also something about the distance between the technology you
can fiddle with and the technology around you. Maybe a crystal radio is
to far divorced from the world of smartphones, to seem of any
relevance, unless you have an interest it that sort of thing.

Floating boats seems an apt term as 50 years ago Radio Caroline had
already been on air for over a year and Radio London was coming up to
its first birthday and a host of other pop stations were soon to join
them. Kids unless they were very square or whatever the term of the
time was would be more interested in the output from a small portable
Transistor radio than the technicalities of the equipment itself, A
crystal radio was probably too far divorced from their world even
then.


G.Harman

On Sunday, 13 December 2015 00:34:15 UTC, wrote:

Floating boats seems an apt term as 50 years ago Radio Caroline had
already been on air for over a year and Radio London was coming up to
its first birthday and a host of other pop stations were soon to join
them. Kids unless they were very square or whatever the term of the
time was would be more interested in the output from a small portable
Transistor radio than the technicalities of the equipment itself, A
crystal radio was probably too far divorced from their world even
then.

Yes. But it did at least have some reason to exist: radios were expensive, and you probably wouldn't have one in the bedroom. Today a smartphone delivers far better and all kids seem to have them.


NT

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.


The thing is that we could make a crystal set - the youngsters cannot make
a smart phone.

On 12/12/2015 4:54 AM, DerbyBorn wrote:

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.


The thing is that we could make a crystal set - the youngsters cannot make
a smart phone.

Good point. When I was a kid, I built loads of HeathKit equipment,
including our first colour TV. Seeing each component, and understanding
its relationship to others made understanding how things worked, much
easier. Today's chips are harder to understand.

On 12/12/15 11:18, S Viemeister wrote:
On 12/12/2015 4:54 AM, DerbyBorn wrote:

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.


The thing is that we could make a crystal set - the youngsters cannot
make
a smart phone.

Good point. When I was a kid, I built loads of HeathKit equipment,
including our first colour TV. Seeing each component, and understanding
its relationship to others made understanding how things worked, much
easier. Today's chips are harder to understand.

Probably still possible to make a primitive FM or AM radio..


--
the biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

On Saturday, 12 December 2015 11:25:53 UTC, The Natural Philosopher wrote:
On 12/12/15 11:18, S Viemeister wrote:
On 12/12/2015 4:54 AM, DerbyBorn wrote:

Tim

I tried to breath in that same sense of wonderment about a crystal set
into a 15 year old relative of mine. I may as well have been talking
Chinese. He simply couldn't understand why anyone wouldn't use their
smartphone and stream audio from the net.

I can only hope my young relative is a one-off in his lack of
curiousity.

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.


The thing is that we could make a crystal set - the youngsters cannot
make
a smart phone.

Good point. When I was a kid, I built loads of HeathKit equipment,
including our first colour TV. Seeing each component, and understanding
its relationship to others made understanding how things worked, much
easier. Today's chips are harder to understand.

Probably still possible to make a primitive FM or AM radio..

Reaction sets are fun, and can even do FM, albeit without the noise rejection of am. But getting radio stations is a non-challenge these days.


NT

On 12/12/15 11:18, S Viemeister wrote:
On 12/12/2015 4:54 AM, DerbyBorn wrote:

Good point. When I was a kid, I built loads of HeathKit equipment,
including our first colour TV. Seeing each component, and understanding
its relationship to others made understanding how things worked, much
easier. Today's chips are harder to understand.

Yes - you could build a *lot* of useful things with a 555, 741 and some
CMOS or TTL logic.

I made (own design unless said):

Tacho for the car (contact breaker spike suppression was actually the
hardest part).

Kitchen timer that was intuitive and was used for years by my Mum.

Heathkit alarm clock that was still the nicest clock I ever had.

Heathkit freezer temperature/door alarm (we were always leaving the door
not quite shut).

Touch dimmer switch;

Caravan Aquaroll water level indicator - *that* was really useful!


These days, the tacho is standard and no CB to pick up off anyway, the
freezer alarm is standard on many units, no one with a smartphone needs
a kitchen timer, dimmer switches are 2 a penny.

Only my water level meter was probably still better than most of what's
on sale today.

and for everything you'd use an AVR or PIC and write some code...

On Saturday, 12 December 2015 19:11:52 UTC, Tim Watts wrote:

Yes - you could build a *lot* of useful things with a 555, 741 and some
CMOS or TTL logic.

I made (own design unless said):

Tacho for the car (contact breaker spike suppression was actually the
hardest part).

Kitchen timer that was intuitive and was used for years by my Mum.

Heathkit alarm clock that was still the nicest clock I ever had.

Heathkit freezer temperature/door alarm (we were always leaving the door
not quite shut).

Touch dimmer switch;

Caravan Aquaroll water level indicator - *that* was really useful!


These days, the tacho is standard and no CB to pick up off anyway, the
freezer alarm is standard on many units, no one with a smartphone needs
a kitchen timer, dimmer switches are 2 a penny.

Only my water level meter was probably still better than most of what's
on sale today.

and for everything you'd use an AVR or PIC and write some code...

Do you still have the circuit for the timer?


NT

"pamela" wrote in message
...

I can only hope my young relative is a one-off in his lack of
curiousity.


Dream on.


Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

It's a wonder the shower of ****e leaving school these days can even manage
to tie their own shoelaces or wipe their own arses without a smart phone
app.

--
Adam

On Sunday, 13 December 2015 12:46:22 UTC, ARW wrote:
"pamela" wrote in message
...

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

It's a wonder the shower of ****e leaving school these days can even manage
to tie their own shoelaces or wipe their own arses without a smart phone
app.

sadly too often true. What were we like back then?


NT

On 13/12/2015 15:56, wrote:
On Sunday, 13 December 2015 12:46:22 UTC, ARW wrote:
"pamela" wrote in message
...

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

It's a wonder the shower of ****e leaving school these days can even manage
to tie their own shoelaces or wipe their own arses without a smart phone
app.

sadly too often true. What were we like back then?

I think our elders thought we were. It's a sign of age when you start
chastising school leavers!

I suspect many here have stopped thinking policeman are getting younger
by coming to terms with this fact years ago? :-)

In message , Fredxxx
writes

I suspect many here have stopped thinking policeman are getting younger
by coming to terms with this fact years ago? :-)

I went to son's parents' evening last week. I thought at least one of
the teachers was a pupil. Seriously.
--
Graeme

"Fredxxx" wrote in message
...
On 13/12/2015 15:56, wrote:
On Sunday, 13 December 2015 12:46:22 UTC, ARW wrote:
"pamela" wrote in message
...

Hopefully other youngsters are far more inquisitive and would show real
interest. Or maybe not? Tell me.

It's a wonder the shower of ****e leaving school these days can even
manage
to tie their own shoelaces or wipe their own arses without a smart phone
app.

sadly too often true. What were we like back then?

I think our elders thought we were. It's a sign of age when you start
chastising school leavers!

It's a pity that you cannot chastise people that are still at school without
a police officer turning up at your door 24 hours later.





--
Adam