Re: Quick reminder that, in case of leccy/broadband/phone total blackout...

[The Natural Philosopher]

On 04/09/2022 13:16, The Legal Occupier wrote:
> ... crystal radios work without battery or mains. (And I'm not talking
> of crank/wind up radios).
>
> I haven't used a crystal radio for probably 35 years and I am not sure
> what you'd pick up nowadays (probably only Radio Moscow or your local
> Asian station on MW) but they are dirt cheap to make and, despite the
> name, they don't need a crystal.
>
Well they do need a germanium diode.

Which is what the original 'cats whisker' and crystal , was.

>


--
"Women actually are capable of being far more than the feminists will
let them."

[Andrew]

On 04/09/2022 13:16, The Legal Occupier wrote:
> ... crystal radios work without battery or mains. (And I'm not talking
> of crank/wind up radios).
>
> I haven't used a crystal radio for probably 35 years and I am not sure
> what you'd pick up nowadays (probably only Radio Moscow or your local
> Asian station on MW) but they are dirt cheap to make and, despite the
> name, they don't need a crystal.
>
>

Sadly, not much use unless someone is transmitting something that you
can tune in to. Might just as well buy an old south-sea sea shell and
listen to the sound of 'waves'.

[Colin Bignell]

On 04/09/2022 13:27, The Natural Philosopher wrote:
> On 04/09/2022 13:16, The Legal Occupier wrote:
>> ... crystal radios work without battery or mains. (And I'm not talking
>> of crank/wind up radios).
>>
>> I haven't used a crystal radio for probably 35 years and I am not sure
>> what you'd pick up nowadays (probably only Radio Moscow or your local
>> Asian station on MW) but they are dirt cheap to make and, despite the
>> name, they don't need a crystal.
>>
> Well they do need a germanium diode.
>
> Which is what the original 'cats whisker' and crystal , was.

The one I built as a kid used the latter. Couldn't hear much on it though.

--
Colin Bignell

[Custos Custodum]

On Sun, 4 Sep 2022 13:27:43 +0100, The Natural Philosopher
<t...@invalid.invalid> wrote:

>On 04/09/2022 13:16, The Legal Occupier wrote:
>> ... crystal radios work without battery or mains. (And I'm not talking
>> of crank/wind up radios).
>>
>> I haven't used a crystal radio for probably 35 years and I am not sure
>> what you'd pick up nowadays (probably only Radio Moscow or your local
>> Asian station on MW) but they are dirt cheap to make and, despite the
>> name, they don't need a crystal.
>>
>Well they do need a germanium diode.
>
>Which is what the original 'cats whisker' and crystal , was.
>

Wasn't that galena (lead sulfide)?

[Dave Plowman (News)]

In article <tf25ub$9lp$1...@gioia.aioe.org>,

I've got a Truvox radio jack here. Basically a crystal set you plugged
into a tape recorder, etc many moons ago. My school used them to record
schools broadcasts in the 50s.

Still works. On LW and MW. With a decent aerial.

--
*Growing old is inevitable, growing up is optional *

Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

[Jim Stewart ...]

On 04/09/2022 14:07, Dave Plowman (News) wrote:
> In article <tf25ub$9lp$1...@gioia.aioe.org>,
> Andrew <Andrew9...@mybtinternet.com> wrote:
>> On 04/09/2022 13:16, The Legal Occupier wrote:
>>> ... crystal radios work without battery or mains. (And I'm not talking
>>> of crank/wind up radios).
>>>
>>> I haven't used a crystal radio for probably 35 years and I am not sure
>>> what you'd pick up nowadays (probably only Radio Moscow or your local
>>> Asian station on MW) but they are dirt cheap to make and, despite the
>>> name, they don't need a crystal.
>>>
>>>
>
>> Sadly, not much use unless someone is transmitting something that you
>> can tune in to. Might just as well buy an old south-sea sea shell and
>> listen to the sound of 'waves'.
>
> I've got a Truvox radio jack here. Basically a crystal set you plugged
> into a tape recorder, etc many moons ago. My school used them to record
> schools broadcasts in the 50s.
>
> Still works. On LW and MW. With a decent aerial.
>

....and earth

[Paul]

My set, the problem with it was that it had no selectivity.
The stations were just a jumble.

But it did have a lot of signal. You could leave the piezo
headphones on the table, and get room filling sound.

The detector was a 1N34A. That was practically the first
new electronic part I ever bought.

Mine picked up AM between 550KHz and 1200KHz or so. I don't think
any other bands were coming in. They would be swamped at that
time, by the level of AM transmission used.

If there was an emergency broadcast of some sort, my little
set would never have made it intelligible.

And when I got one of those Ferranti three-legged things,
I don't think that was intelligible either. Still the same
problem that Paul could not make a tuned circuit worth a darn :-)

Paul

[The Natural Philosopher]

I think it probably was,


--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

[Brian]

Usually, although other things were used - perhaps the most famous being a
razor blade.

Germanium diodes came along later, when crystal sets were little more than
things budding radio amateurs / geeks played with.


You should still be able to receive stations on MW and LW with one. I last
demonstrated one perhaps 20 years back and was able to receive several
stations. You need a long bit of wire for an antenna - ideally 50 + ft and
and earth, another length of wire along the ground about the same length
would do.

I used to have a beautiful Bakelite Crystal set but it went astray over the
years. It may be in one of the boxes in the loft.

[Kron]

On Sun, 04 Sep 2022 22:16:22 +1000, The Legal Occupier

<ottavio2006...@yahoo.com> wrote:

> ... crystal radios work without battery or mains. (And I'm not talking
> of crank/wind up radios).
>
> I haven't used a crystal radio for probably 35 years and I am not sure
> what you'd pick up nowadays (probably only Radio Moscow or your local
> Asian station on MW)

Any AM station close enough.

> but they are dirt cheap to make and, despite the name, they don't need a
> crystal.

But do need a diode.

[Rod Speed]

On Mon, 05 Sep 2022 00:30:55 +1000, Paul <nos...@needed.invalid> wrote:

> On 9/4/2022 8:39 AM, Colin Bignell wrote:
>> On 04/09/2022 13:27, The Natural Philosopher wrote:
>>> On 04/09/2022 13:16, The Legal Occupier wrote:
>>>> ... crystal radios work without battery or mains. (And I'm not
>>>> talking of crank/wind up radios).
>>>>
>>>> I haven't used a crystal radio for probably 35 years and I am not
>>>> sure what you'd pick up nowadays (probably only Radio Moscow or your
>>>> local Asian station on MW) but they are dirt cheap to make and,
>>>> despite the name, they don't need a crystal.
>>>>
>>> Well they do need a germanium diode.
>>>
>>> Which is what the original 'cats whisker' and crystal , was.
>> The one I built as a kid used the latter. Couldn't hear much on it
>> though.
>>
>
> My set, the problem with it was that it had no selectivity.
> The stations were just a jumble.

Easily fixed with a better design.

> But it did have a lot of signal. You could leave the piezo
> headphones on the table, and get room filling sound.

Bullshit on the room filling.

> The detector was a 1N34A. That was practically the first
> new electronic part I ever bought.

> Mine picked up AM between 550KHz and 1200KHz or so. I don't think
> any other bands were coming in. They would be swamped at that
> time, by the level of AM transmission used.

> If there was an emergency broadcast of some sort, my little
> set would never have made it intelligible.

But a better designed one would.

[Peeler]

On Mon, 05 Sep 2022 02:10:15 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

--
The Natural Philosopher about senile Rodent:
"Rod speed is not a Brexiteer. He is an Australian troll and arsehole."
Message-ID: <pu07vj$s5$2...@dont-email.me>

[Peeler]

On Mon, 05 Sep 2022 01:58:16 +1000, Kron, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

--

Keema Nam addressing nym-shifting senile Rodent:
"You are now exposed as a liar, as well as an ignorant troll."
"MID: <0001HW.22B654E700...@news.giganews.com>"

[Roger Mills]

On 04/09/2022 13:16, The Legal Occupier wrote:
> ... crystal radios work without battery or mains. (And I'm not talking
> of crank/wind up radios).
>
> I haven't used a crystal radio for probably 35 years and I am not sure
> what you'd pick up nowadays (probably only Radio Moscow or your local
> Asian station on MW) but they are dirt cheap to make and, despite the
> name, they don't need a crystal.
>
>

Good luck with receiving DAB!
--
Cheers,
Roger

[The Hanging Baskets of Babylon]

The Legal Occupier wrote:
> ... crystal radios work without battery or mains. (And I'm not talking
> of crank/wind up radios).
>
> I haven't used a crystal radio for probably 35 years and I am not sure
> what you'd pick up nowadays (probably only Radio Moscow or your local
> Asian station on MW) but they are dirt cheap to make and, despite the
> name, they don't need a crystal.
>

I could only ever get Radio 4.

[williamwright]

Home Service

Bill

[Martin Brown]

Even with a DAB receiver you would struggle without mains power.
In a power cut they eat batteries at a rate of four per 8 hours of use.

A classic analogue FM radio would last more than a week!

--
Regards,
Martin Brown

[The Hanging Baskets of Babylon]

Is that a more likely station? We (a gang of lads that were interested
in odd things) used to make crystal sets with things like denuded sprung
mattresses, or even old motorbikes, as aerials, and only ever got the
one station. I think we guessed it was Radio 4, but it was too long ago
to be certain. I still have the Ladybird book that we more or less
followed, and a couple of the old OC71's.

[Brian Gaff]

The zn 414, was not intended as a straight crystal set but just a detector
of am on a radio, that had more gain than just a diode, often meaning you
could get away with only on IF stage. It needed to be lightly coupled to
the tuned circuit to maintain the Q in the circuit. Often transfilters
tended to get used and these though selective were low output.
As for Crystal sets, well, a one transistor free power circuit using a
germanium transistor like an oc44 actually worked quite loudly with a
crystal earpiece, but you were still playing with a very low impedance input
and it needed to be lightly coupled to get selectivity. Used to work quite
well on long wave with a good aerial.
I am told that some mosfets can be used as well as their gate is higher
impedance, but I'd seriously doubt it would work well being made of silicon.
Brian

--

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