Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW as well


--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

I depends where you live. If you're fairly close to an AM transmitter
then you stand a good chance. Many AM transmitters have been shut down,
but if you live near Droitwich, for example, you're on the pig's back.

Wikipedia has a list of European (which we're still in) AM transmitters.


Cheers
--
Syd

Yes, Medium wave is full of them. It depends where you are of course. The
issue with crystal sets is selectivity. In the case of a basic one with a
tapped coil and tuning capacitor, its hard to just get one station without
bleed through. Here in sw London all you seem to get on medium wave is the
God station Premier.
Brian

"Dan S. MacAbre" wrote in message
...
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape recorder
from the tip, and fix it. That was about my limit. I used to enjoy
making crystal radios from some of the bits I'd have lying around, but no
matter what I used, I only ever seemed to be able to pick up what seemed
to be radio 4. If you were to build one nowadays, would there be any
suitable non-digital station left to pick up?

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!

There was even a supercharged version of the crystal set, using a germanium
transistor which harvested the power from the aerial to give some
amplification. It was not very good but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414, which was a thre
pin trf radio. It was often used instead of a diode in superhets in the
70s.


Of course my favourite sets were those with regeneration or reaction as it
used to be named.
Then there was the superregenerative sets. One transistor and it could get
fm or aircraft etc, little selectivity, but its mai drawback was the crud it
generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in message
...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW as well


--
All political activity makes complete sense once the proposition that all
government is basically a self-legalising protection racket, is fully
understood.


--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!

In article ,
Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Of course. The AM band is packed full. That method of transmission is the
same as always.

--
*Virtual reality is its own reward *

Dave Plowman London SW
To e-mail, change noise into sound.

"Syd Rumpo" wrote in message
...
On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

I depends where you live. If you're fairly close to an AM transmitter
then you stand a good chance. Many AM transmitters have been shut down,
but if you live near Droitwich, for example, you're on the pig's back.

Wikipedia has a list of European (which we're still in) AM transmitters.

We had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
It seems to have been mislaid.
If you lived near Droitwich, florrie tubes would glow without power, so I
heard

In message , Dan S. MacAbre
writes

If you were to build one nowadays, would there be any suitable
non-digital station left to pick up?

What a coincidence! I recently dug mine out of the shed, to play with.
Build mid sixties and not used since. I have even bought a little ear
piece (via eBay) but have not yet rigged up suitable aerial and earth
connections.

See here for a list of stations :

http://www.mediumwaveradio.com/uk.php

Back then, I was in North Herts and could easily pick up the BBC
stations and the pirates out on the North Sea, and even Luxembourg in
the evenings. Now, I'm in NE Scotland, and should be able to pick up
Aberdeen and Hopeman, and possibly further afield.

--
Graeme

On 25/02/2016 11:14, bm wrote:

snip

We had one of these -
http://www.museumoftechnology.org.uk...s/A1318_ex.jpg
It seems to have been mislaid.

That's a shame, it looks great.

If you lived near Droitwich, florrie tubes would glow without power, so I
heard

Not quite, but on a tour of the transmitter, the guide would hold up a
tube and it would spring to life.

I did wonder if nearby you could receive the long wave transmissions -
198kHz @ 500kW - with just wire, a diode and a loudspeaker.

Cheers
--
Syd

On Thu, 25 Feb 2016 10:56:15 -0000
"Brian Gaff" wrote:

Of course my favourite sets were those with regeneration or reaction
as it used to be named.
Then there was the superregenerative sets. One transistor and it
could get fm or aircraft etc, little selectivity, but its mai
drawback was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

My school had an old Scientific Encyclopedia which included instructions
for making a Morse Code-like Wireless transmitter. It used a spark gap
to generate the signal.
We didn't build one after all.

--
Davey.

On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Gosh, that brought back memories. A crystal set was the first thing I
made, using a soldering iron shoved in the coal fire to heat it up.
Probably aged about 8 and (slightly) more than half a century ago :-(

Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Okay, thanks for the great replies. I had a Ladybird book that showed
how to make them. Beautiful illustrations that I still look at fondly.
The first version was without batteries, and then it evolved into
something amplified with an OC71. It said to drive a long copper tube
into the ground for the earth side, but I just used a mains plug. And
the aerial was supposed to be something like a washing line, but I used
a bit of wire dangled across the room; and once, an old mattress in the
loft (which was no better). That may have reduced what I was able to
pick up :-)

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set, using
a germanium transistor which harvested the power from the aerial
to give some amplification. It was not very good but better than
a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414, which
was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor and
it could get
fm or aircraft etc, little selectivity, but its mai drawback was
the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in message
...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded me of
some of my mis-spent youth. I never knew enough about
electronics to design anything, but I could usually get
something like an amp or a tape recorder from the tip, and fix
it. That was about my limit. I used to enjoy making crystal
radios from some of the bits I'd have lying around, but no
matter what I used, I only ever seemed to be able to pick up
what seemed to be radio 4. If you were to build one nowadays,
would there be any suitable non-digital station left to pick
up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW as
well


--
All political activity makes complete sense once the
proposition that all government is basically a self-legalising
protection racket, is fully understood.


In my book any external power for a crystal set is cheating. Even
from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from a
powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be obtained from
such a thing?

In article ,
Dan S. MacAbre wrote:
Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used
to enjoy making crystal radios from some of the bits I'd have lying
around, but no matter what I used, I only ever seemed to be able to
pick up what seemed to be radio 4. If you were to build one nowadays,
would there be any suitable non-digital station left to pick up?

Okay, thanks for the great replies. I had a Ladybird book that showed
how to make them. Beautiful illustrations that I still look at fondly.
The first version was without batteries, and then it evolved into
something amplified with an OC71. It said to drive a long copper tube
into the ground for the earth side, but I just used a mains plug. And
the aerial was supposed to be something like a washing line, but I used
a bit of wire dangled across the room; and once, an old mattress in the
loft (which was no better). That may have reduced what I was able to
pick up :-)

Thing is that one time all radios worked best with a long external aerial.
Many would have one running the length of the garden. Ferrite rod aerials
made this unnecessary for most.

A crystal set has no RF gain. So needs a very strong signal to work at all.

--
*Why is it that rain drops but snow falls?

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Dan S. MacAbre wrote:
Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from a
powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be obtained from
such a thing?

You can have reasonable lighting run purely off RF. If you are close
enough to a powerful transmitter and have a big enough aerial. Until they
catch you, of course.

A standard fluorescent tube will light with no other connections close to
some TX aerials.

--
*Support bacteria - they're the only culture some people have *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from a
powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be obtained from
such a thing?

You can have reasonable lighting run purely off RF. If you are close
enough to a powerful transmitter and have a big enough aerial. Until they
catch you, of course.

It's actually been made illegal, or something? I'd have thought they
would encourage you to do it. I was wondering if you could just slowly
charge batteries off it. I never imagined you could run lighting off it.

A standard fluorescent tube will light with no other connections close to
some TX aerials.

Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from a
powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be obtained from
such a thing?

You can have reasonable lighting run purely off RF. If you are close
enough to a powerful transmitter and have a big enough aerial. Until they
catch you, of course.

A standard fluorescent tube will light with no other connections close to
some TX aerials.


I've just discovered a few articles that discuss what they call RF-based
Energy Harvesting. I don't know if that's the only term for it, but it
certainly sounds interesting.

pamela wrote:
On 12:50 25 Feb 2016, Dan S. MacAbre wrote:

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set,
using a germanium transistor which harvested the power from
the aerial to give some amplification. It was not very good
but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414,
which was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor
and it could get
fm or aircraft etc, little selectivity, but its mai drawback
was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in
message ...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded me
of some of my mis-spent youth. I never knew enough about
electronics to design anything, but I could usually get
something like an amp or a tape recorder from the tip, and
fix it. That was about my limit. I used to enjoy making
crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to
pick up what seemed to be radio 4. If you were to build one
nowadays, would there be any suitable non-digital station
left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW
as well


--
All political activity makes complete sense once the
proposition that all government is basically a
self-legalising protection racket, is fully understood.


In my book any external power for a crystal set is cheating.
Even from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from
a powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be
obtained from such a thing?

I never tried it but I saw it described in a booklet showing dozens
of crystal set circuits.

I wonder if the power extracted depends on the amplitude of the audio
being transmitted at that very moment.


This looks interesting
http://eu.mouser.com/applications/rf_energy_harvesting/

On 25/02/16 14:24, pamela wrote:
On 12:50 25 Feb 2016, Dan S. MacAbre wrote:

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set,
using a germanium transistor which harvested the power from
the aerial to give some amplification. It was not very good
but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414,
which was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor
and it could get
fm or aircraft etc, little selectivity, but its mai drawback
was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in
message ...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded me
of some of my mis-spent youth. I never knew enough about
electronics to design anything, but I could usually get
something like an amp or a tape recorder from the tip, and
fix it. That was about my limit. I used to enjoy making
crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to
pick up what seemed to be radio 4. If you were to build one
nowadays, would there be any suitable non-digital station
left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW
as well


--
All political activity makes complete sense once the
proposition that all government is basically a
self-legalising protection racket, is fully understood.


In my book any external power for a crystal set is cheating.
Even from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from
a powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be
obtained from such a thing?

I never tried it but I saw it described in a booklet showing dozens
of crystal set circuits.

I wonder if the power extracted depends on the amplitude of the audio
being transmitted at that very moment.

would have done, yes, but only instantaneously. I.e. a over a second
loud sound is the same as no sound, but at the moment of the peak of the
audio waveform power is more.

SSSC is the modulation where IIRC the actual power varies with audio.

Not bog standard AM.

--
"I am inclined to tell the truth and dislike people who lie consistently.
This makes me unfit for the company of people of a Left persuasion, and
all women"

On 25/02/16 14:14, Dan S. MacAbre wrote:
Dave Plowman (News) wrote:
In article ,
Dan S. MacAbre wrote:
Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from a
powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be obtained from
such a thing?

You can have reasonable lighting run purely off RF. If you are close
enough to a powerful transmitter and have a big enough aerial. Until they
catch you, of course.

It's actually been made illegal, or something? I'd have thought they
would encourage you to do it. I was wondering if you could just slowly
charge batteries off it. I never imagined you could run lighting off it.

Well average TV transmitter is around 100-250KW and you get 4+ up a
standard mast.

Think broadcast AM is broadly similar.

Which mat be why in the end BBC3 is moving online. It could be that it
costs less for the number of actual viewers.




A standard fluorescent tube will light with no other connections close to
some TX aerials.




--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

On Thursday, February 25, 2016 at 10:30:58 AM UTC, Syd Rumpo wrote:
On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

I depends where you live. If you're fairly close to an AM transmitter
then you stand a good chance. Many AM transmitters have been shut down,
but if you live near Droitwich, for example, you're on the pig's back.

Wikipedia has a list of European (which we're still in) AM transmitters.


My father said he once knew a man who lived near Crystal Palace and claimed he could hear the radio all the time because of a poor metal filling in a tooth.

Robert

In article , RobertL
wrote:
On Thursday, February 25, 2016 at 10:30:58 AM UTC, Syd Rumpo wrote:
On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used
to enjoy making crystal radios from some of the bits I'd have lying
around, but no matter what I used, I only ever seemed to be able to
pick up what seemed to be radio 4. If you were to build one
nowadays, would there be any suitable non-digital station left to
pick up?

I depends where you live. If you're fairly close to an AM transmitter
then you stand a good chance. Many AM transmitters have been shut
down, but if you live near Droitwich, for example, you're on the pig's
back.

Wikipedia has a list of European (which we're still in) AM transmitters.


My father said he once knew a man who lived near Crystal Palace and
claimed he could hear the radio all the time because of a poor metal
filling in a tooth.


but, in those days CP only broadcast tv!

--
from KT24 in Surrey, England

On Thu, 25 Feb 2016 14:24:10 GMT, pamela wrote:

On 12:50 25 Feb 2016, Dan S. MacAbre wrote:

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set,
using a germanium transistor which harvested the power from
the aerial to give some amplification. It was not very good
but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414,
which was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor
and it could get
fm or aircraft etc, little selectivity, but its mai drawback
was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in
message ...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded me
of some of my mis-spent youth. I never knew enough about
electronics to design anything, but I could usually get
something like an amp or a tape recorder from the tip, and
fix it. That was about my limit. I used to enjoy making
crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to
pick up what seemed to be radio 4. If you were to build one
nowadays, would there be any suitable non-digital station
left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW
as well


--
All political activity makes complete sense once the
proposition that all government is basically a
self-legalising protection racket, is fully understood.


In my book any external power for a crystal set is cheating.
Even from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy from
a powerful station used to improve reception of the station you
listen to.


I'd never heard of that. I wonder how much power could be
obtained from such a thing?

I never tried it but I saw it described in a booklet showing dozens
of crystal set circuits.

I bet I had that book too. One of Bernard Bababani's publications
probebly written by Clive Sinclair. It harvested energy from 200kHz to
power a one or two transistor MW circuit.


I wonder if the power extracted depends on the amplitude of the audio
being transmitted at that very moment.

It would if you didn't LPF it first, which would be essential.

No, you are going to have to


--

Graham.

%Profound_observation%

On Thu, 25 Feb 2016 10:08:37 +0000, "Dan S. MacAbre"
wrote:

Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?


Oh yes, AM broadcasts have been much the same since 1922.
My dad gave me my first crystal set when I was about six, I think the
baseboard was a slab of slate with four binding posts for aerial,
earth, and headphones.
The tuner, I later found out, was called a variometer, and I am quite
sure it was exactly like this (you just wouldn't forget something like
that would you?

http://www.lessmiths.com/~kjsmith/crystal/lcoil.shtml

The detector was clearly originally a bare crystal and an adjustable
cat's whisker but someone, presumably my dad, had bridged it with a
new fanged crystal diode, something like this, although not as
symmetrical
http://theodoregray.com/periodictabl...index.s15.html

IIRC it picked up the Light programme from Droitwich (100 miles)
and the Home service from Moorside Edge (30 miles)

--

Graham.

%Profound_observation%

On 25/02/16 15:04, Graham. wrote:
On Thu, 25 Feb 2016 10:08:37 +0000, "Dan S. MacAbre"
wrote:

Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?


Oh yes, AM broadcasts have been much the same since 1922.
My dad gave me my first crystal set when I was about six, I think the
baseboard was a slab of slate with four binding posts for aerial,
earth, and headphones.
The tuner, I later found out, was called a variometer, and I am quite
sure it was exactly like this (you just wouldn't forget something like
that would you?

http://www.lessmiths.com/~kjsmith/crystal/lcoil.shtml

The detector was clearly originally a bare crystal and an adjustable
cat's whisker but someone, presumably my dad, had bridged it with a
new fanged crystal diode, something like this, although not as
symmetrical
http://theodoregray.com/periodictabl...index.s15.html

IIRC it picked up the Light programme from Droitwich (100 miles)
and the Home service from Moorside Edge (30 miles)

basically a coil and tuning capacitor like from an old tranny radio.,
plus a oa91 germanium diode and a crystal earpiece should all still work.



--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

In article ,
Dan S. MacAbre wrote:
You can have reasonable lighting run purely off RF. If you are close
enough to a powerful transmitter and have a big enough aerial. Until they
catch you, of course.

It's actually been made illegal, or something?

I'd guess it would be stealing energy or somesuch.

I'd have thought they
would encourage you to do it.

Trouble is it removes or reduces the RF signal beyond that point.
Story was a farmer or something used it to light a cow shed or whatever -
close to the BBC LW tramsmitter and caused a vast shadow in its output.
Many many years ago.


I was wondering if you could just slowly
charge batteries off it. I never imagined you could run lighting off it.

To get any appreciable current, you'd need a very large and efficient
aerial and be close to the transmitter. Likely cost far more than anything
you could get for free.

--
*Too many clicks spoil the browse *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
charles wrote:
My father said he once knew a man who lived near Crystal Palace and
claimed he could hear the radio all the time because of a poor metal
filling in a tooth.


but, in those days CP only broadcast tv!

And these days, only FM radio wise? Which would be less likely to produce
an audio output under those conditions.

Perhaps it was the old AM TV sound.

--
*Life is hard; then you nap

Dave Plowman London SW
To e-mail, change noise into sound.

On Thu, 25 Feb 2016 16:14:31 GMT, pamela wrote:

On 15:03 25 Feb 2016, Graham. wrote:

fOn Thu, 25 Feb 2016 14:24:10 GMT, pamela
wrote:

On 12:50 25 Feb 2016, Dan S. MacAbre wrote:

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set,
using a germanium transistor which harvested the power from
the aerial to give some amplification. It was not very good
but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414,
which was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor
and it could get
fm or aircraft etc, little selectivity, but its mai drawback
was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in
message ...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded
me of some of my mis-spent youth. I never knew enough
about electronics to design anything, but I could usually
get something like an amp or a tape recorder from the tip,
and fix it. That was about my limit. I used to enjoy
making crystal radios from some of the bits I'd have lying
around, but no matter what I used, I only ever seemed to
be able to pick up what seemed to be radio 4. If you were
to build one nowadays, would there be any suitable
non-digital station left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW
as well


--
All political activity makes complete sense once the
proposition that all government is basically a
self-legalising protection racket, is fully understood.


In my book any external power for a crystal set is cheating.
Even from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy
from a powerful station used to improve reception of the
station you listen to.


I'd never heard of that. I wonder how much power could be
obtained from such a thing?

I never tried it but I saw it described in a booklet showing
dozens of crystal set circuits.

I bet I had that book too. One of Bernard Bababani's
publications probebly written by Clive Sinclair. It harvested
energy from 200kHz to power a one or two transistor MW circuit.

This looks like the booklet I had. Maybe you too. :-)

It says 1981 but I thought I had it before then.

"Electronics Simplified: Crystal Set Construction"
http://www.amazon.co.uk//dp/0859340678


I wonder if the power extracted depends on the amplitude of the
audio being transmitted at that very moment.

It would if you didn't LPF it first, which would be essential.

No, you are going to have to

LPF?

Lowpass filter. probebly an series R and a shunt C to remove the
modulation and just leave DC.



--

Graham.

%Profound_observation%

On 25/02/2016 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

A crystal set should pick up any stations still broadcasting in AM on
medium wave (perhaps long wave if tuned properly). There's quite a few.

The first one I made was very primitive: a diode with an aerial on one
side and an earth on the other, and headphones across it. No tuner so it
picked up everything at once, but Radio 4 was dominant, which suited me.
This was near Brookman's Park so maybe that influenced what I could pick up.

--
Bartc

On Thu, 25 Feb 2016 15:11:48 +0000, The Natural Philosopher
wrote:

On 25/02/16 15:04, Graham. wrote:
On Thu, 25 Feb 2016 10:08:37 +0000, "Dan S. MacAbre"
wrote:

Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?


Oh yes, AM broadcasts have been much the same since 1922.
My dad gave me my first crystal set when I was about six, I think the
baseboard was a slab of slate with four binding posts for aerial,
earth, and headphones.
The tuner, I later found out, was called a variometer, and I am quite
sure it was exactly like this (you just wouldn't forget something like
that would you?

http://www.lessmiths.com/~kjsmith/crystal/lcoil.shtml

The detector was clearly originally a bare crystal and an adjustable
cat's whisker but someone, presumably my dad, had bridged it with a
new fanged crystal diode, something like this, although not as
symmetrical
http://theodoregray.com/periodictabl...index.s15.html

IIRC it picked up the Light programme from Droitwich (100 miles)
and the Home service from Moorside Edge (30 miles)

basically a coil and tuning capacitor like from an old tranny radio.,
plus a oa91 germanium diode and a crystal earpiece should all still work.

Don't forget to factor in the disapointment due to our hearing not
being what it was 50 years ago!



--

Graham.

%Profound_observation%

On Thu, 25 Feb 2016 10:08:37 +0000, Dan S. MacAbre wrote:

I only ever seemed to be able to pick up what
seemed to be radio 4.

I'm guessing that would have been the World Service. At 1MW DC input
power, it dominated the xtal radios of the small boys all over Britain.
Does this sound familiar:

https://www.youtube.com/watch?v=B4BZrSj2VU4

On 25/02/16 17:41, Graham. wrote:
On Thu, 25 Feb 2016 16:14:31 GMT, pamela wrote:

On 15:03 25 Feb 2016, Graham. wrote:

fOn Thu, 25 Feb 2016 14:24:10 GMT, pamela
wrote:

On 12:50 25 Feb 2016, Dan S. MacAbre wrote:

pamela wrote:
On 10:56 25 Feb 2016, Brian Gaff wrote:

There was even a supercharged version of the crystal set,
using a germanium transistor which harvested the power from
the aerial to give some amplification. It was not very good
but better than a straight crystal set.
Then if you had a 1.5 v battery you could get the ZN414,
which was a thre
pin trf radio. It was often used instead of a diode in
superhets in the 70s.


Of course my favourite sets were those with regeneration or
reaction as it used to be named.
Then there was the superregenerative sets. One transistor
and it could get
fm or aircraft etc, little selectivity, but its mai drawback
was the crud it generated on any radio nearby.

Those were such simple days.. sigh.
Brian

"The Natural Philosopher" wrote in
message ...
On 25/02/16 10:08, Dan S. MacAbre wrote:
Apologies to those who know about this stuff, if this is a
stupid question. Seeing the electronics thread reminded
me of some of my mis-spent youth. I never knew enough
about electronics to design anything, but I could usually
get something like an amp or a tape recorder from the tip,
and fix it. That was about my limit. I used to enjoy
making crystal radios from some of the bits I'd have lying
around, but no matter what I used, I only ever seemed to
be able to pick up what seemed to be radio 4. If you were
to build one nowadays, would there be any suitable
non-digital station left to pick up?

Oh yes, there's a few. Radio 4 on long wave and a few on MW
as well


--
All political activity makes complete sense once the
proposition that all government is basically a
self-legalising protection racket, is fully understood.


In my book any external power for a crystal set is cheating.
Even from a solar cell!

Only exception, if it's needed at all, are those parasitic
circuits which used two tuners. One to draw radio energy
from a powerful station used to improve reception of the
station you listen to.


I'd never heard of that. I wonder how much power could be
obtained from such a thing?

I never tried it but I saw it described in a booklet showing
dozens of crystal set circuits.

I bet I had that book too. One of Bernard Bababani's
publications probebly written by Clive Sinclair. It harvested
energy from 200kHz to power a one or two transistor MW circuit.

This looks like the booklet I had. Maybe you too. :-)

It says 1981 but I thought I had it before then.

"Electronics Simplified: Crystal Set Construction"
http://www.amazon.co.uk//dp/0859340678


I wonder if the power extracted depends on the amplitude of the
audio being transmitted at that very moment.

It would if you didn't LPF it first, which would be essential.

No, you are going to have to

LPF?

Lowpass filter. probebly an series R and a shunt C to remove the
modulation and just leave DC.


rectifier and capacitor actually




--
Karl Marx said religion is the opium of the people.
But Marxism is the crack cocaine.

In article ,
"Dan S. MacAbre" writes:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Funny you should mention this...
A couple of weeks ago, I stayed over at my parents, and in the bookshelf
was my old Ladybird book on making a radio, which takes you through the
stages of making the receiver and then adding an amplifier to it.
If you can still buy OC71's, it would still work today. ;-)

http://www.mds975.co.uk/Content/geor...trf_radio.html

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

In message , "Dave Plowman (News)"
writes
In article ,
charles wrote:
My father said he once knew a man who lived near Crystal Palace and
claimed he could hear the radio all the time because of a poor metal
filling in a tooth.


but, in those days CP only broadcast tv!

And these days, only FM radio wise? Which would be less likely to produce
an audio output under those conditions.

Perhaps it was the old AM TV sound.

These days, Crystal Palace actually does transmit MW - 720kHz Radio 4
fill-in. It used to be at Lots Road power station
https://www.google.co.uk/?gws_rd=ssl...+power+station

--
Ian

On 25/02/2016 22:43, Chris Hogg wrote:
On Thu, 25 Feb 2016 22:21:00 GMT, pamela wrote:

snip

Valves were almost all there were in those days. Transistors were only
just becoming available. 'Practical Wireless' had pages and pages
advertising all sorts of valves with their prices, like this
http://tinyurl.com/hg6wz6m click on the arrow bottom right of the
screen to turn the pages. Even some circuits with transistors, I see.

You may like this...

http://www.americanradiohistory.com/...d_Magazine.htm

Cheers
--
Syd

In article ,
Chris Hogg wrote:
On Thu, 25 Feb 2016 22:21:00 GMT, pamela wrote:

On 16:52 25 Feb 2016, Chris Hogg wrote:

On Thu, 25 Feb 2016 16:14:31 GMT, pamela
wrote:


It says 1981 but I thought I had it before then.

"Electronics Simplified: Crystal Set Construction"
http://www.amazon.co.uk//dp/0859340678


'Radio for Boys', E.N. Bradley, 1956 edition, Junior Teach
Yourself Books. http://tinyurl.com/h7jgjdq Oddly enough, this
one says it was a school prize and has a label inside to that
effect. So was mine, and so has mine.

Covered crystal set, one- two- three- and four-valve TRF battery
receivers, battery and mains supehets. Still got the book! I
don't recall ever getting beyond the one-valve receiver,
although I have component costs for the others scribbled in
pencil in the margins, e.g. Mullard DL35 output valve 12/6,
Octal valve holder 6d etc. Those were the days!

Well done for getting as far as that one-valve receiver! Valves
are before my time.

This table says 12/6 in 1960 is equivalent to a bit more than £11 in
today's money. That seems too little.

http://swanlowpark.co.uk/rpiannual.jsp

Valves were almost all there were in those days. Transistors were only
just becoming available.

we "experimented" with transitors at school in 1957. I still have a copy
of the Mullard Book - Transistors for the Experimenter - published in
August 1956!

--
from KT24 in Surrey, England

"Chris Hogg" wrote in message
...
Valves were almost all there were in those days. Transistors were only
just becoming available. 'Practical Wireless' had pages and pages
advertising all sorts of valves with their prices, like this
http://tinyurl.com/hg6wz6m click on the arrow bottom right of the
screen to turn the pages. Even some circuits with transistors, I see.


Clive's 3 pages of adverts start on page 379
including the Sincro Micro 6 the Worlds Smallest
Radio for 59/6 on page 380

michael adams

....

On 25/02/16 22:18, Andrew Gabriel wrote:
In article ,
"Dan S. MacAbre" writes:
Apologies to those who know about this stuff, if this is a stupid
question. Seeing the electronics thread reminded me of some of my
mis-spent youth. I never knew enough about electronics to design
anything, but I could usually get something like an amp or a tape
recorder from the tip, and fix it. That was about my limit. I used to
enjoy making crystal radios from some of the bits I'd have lying around,
but no matter what I used, I only ever seemed to be able to pick up what
seemed to be radio 4. If you were to build one nowadays, would there be
any suitable non-digital station left to pick up?

Funny you should mention this...
A couple of weeks ago, I stayed over at my parents, and in the bookshelf
was my old Ladybird book on making a radio, which takes you through the
stages of making the receiver and then adding an amplifier to it.
If you can still buy OC71's, it would still work today. ;-)

http://www.mds975.co.uk/Content/geor...trf_radio.html

You can still buy oc71s all right

But why not use something better?

--
All political activity makes complete sense once the proposition that
all government is basically a self-legalising protection racket, is
fully understood.

In article ,
Cursitor Doom wrote:
On Thu, 25 Feb 2016 10:08:37 +0000, Dan S. MacAbre wrote:

I only ever seemed to be able to pick up what
seemed to be radio 4.

I'm guessing that would have been the World Service. At 1MW DC input
power, it dominated the xtal radios of the small boys all over Britain.
Does this sound familiar:

https://www.youtube.com/watch?v=B4BZrSj2VU4

I don't think so. The world service being easily available at all times in
the UK is relatively recent.

The most likely transmitter to receive (apart from a very local one) would
have been Droitwich LW. Which transmitted the Light Programme when I were
a lad. Later changed to R4 during the day, WS at night.

--
*I'm not your type. I'm not inflatable.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Andrew Gabriel wrote:
If you can still buy OC71's, it would still work today. ;-)

Plenty of equivalents you could use. For rather less than 7/6d each. ;-)

--
*A 'jiffy' is an actual unit of time for 1/100th of a second.

Dave Plowman London SW
To e-mail, change noise into sound.