Questions About Construction Of The Australian Mystery Crystal Set

On Mar 10, 5:53 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:
> "Dave.H" wrote:
> > can I substitute the detector for a 1N34?
>
> You might do rather well with a zero bias schottky diode.
>
> Failing that, any germamium point-contact type (like the 1N34) would be a
> decent sub.
>
> Graham

I'll go with the 1N34. I'm also going to install a 1S5 tube as a
second detector, switchable between the two, with a 'D' cell powering
the filament.

"Dave.H" <(E-Mail Removed)> wrote in message
news:940ac3e1-5a04-4881-8d2f-(E-Mail Removed)...
> On Mar 10, 5:53 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
> wrote:
>> "Dave.H" wrote:
>> > can I substitute the detector for a 1N34?
>>
>> You might do rather well with a zero bias schottky diode.
>>
>> Failing that, any germamium point-contact type (like the 1N34) would be a
>> decent sub.
>>
>> Graham
>
> I'll go with the 1N34. I'm also going to install a 1S5 tube as a
> second detector, switchable between the two, with a 'D' cell >powering the
> filament.

Hi Dave,
I almost feel bad giving you this URL, it is so full of useful information
that it may be a while before you have time to get anything done. See
section 1. Out of the 29 atricles, I think 5 or 6 are about how to improve
the diode/detector operation. Oh, and see #19, Ben discusses the 1932
"Mystery Crystal Radio"
http://www.bentongue.com/xtalset/xtalset.html
Have fun, Mike
*and what's this stuff about a D cell on a crystal radio :-)

On Mar 10, 12:11*am, "Dave.H" <the19...@googlemail.com> wrote:

> I'll go with the 1N34. *I'm also going to install a 1S5 tube as a
> second detector, switchable between the two, with a 'D' cell powering
> the filament.

Gack! How about using a transistor (base -emitter of PN3904 connect
B to coil, E to phones), and a 1k resistor from the collector to
battery (+)?
Battery (-) to ground.

Or go low-tech and use a two-potato battery.

<http://www.ehow.com/how_18637_make-potato-clock.html>

On Mar 11, 6:05 am, "amdx" <a...@knology.net> wrote:

*and what's this stuff about a D cell on a crystal radio :-)

I got the idea from one of Dave Schmarder's radios, #26

http://www.schmarder.com/radios/crystal/26.htm

"Dave.H" <(E-Mail Removed)> wrote in message
news:039c2b9f-720f-49b2-ac76-(E-Mail Removed)...
> On Mar 11, 6:05 am, "amdx" <a...@knology.net> wrote:
>
> *and what's this stuff about a D cell on a crystal radio :-)
>
> I got the idea from one of Dave Schmarder's radios, #26
>
> http://www.schmarder.com/radios/crystal/26.htm

Hi Dave,
My point was, the purists would shudder at the thought of an external
power source on a crystal radio. Now if you extract the power from a strong
local and use that to amplify a weak signal then your doing good work.
Mike

Dave.H wrote:
> On Mar 10, 11:45 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
> wrote:
>> "Dave.H" wrote:
>>> what is double silk covered wire
>> It's wire insulated with silk.
>>
>>> and do I really have use that?
>> Not unless you want it to be 'period authentic'.
>>
>> Graham
>
> Not really, I'm building it on a metal chassis (coil mounted above,
> vertically) and don't really care about vintage looks. I can't seem to
> find wire of the right diameter, though, that's the only part I've yet
> to find.

A metal chassis can influence performance very much,
because metal in front of a coil acts as a shorted
winding.
I advise to test things without a chassis, on a non-metal
table surface, and when it performs as intended,
try it in your metal housing.
I would choose a wooden or plastic box however.

On 3/11/08 5:15 AM, in article 91512$47d674c2$18d6b40c$(E-Mail Removed),
"amdx" <(E-Mail Removed)> wrote:

>
> "Dave.H" <(E-Mail Removed)> wrote in message
> news:039c2b9f-720f-49b2-ac76-(E-Mail Removed)...
>> On Mar 11, 6:05 am, "amdx" <a...@knology.net> wrote:
>>
>> *and what's this stuff about a D cell on a crystal radio :-)
>>
>> I got the idea from one of Dave Schmarder's radios, #26
>>
>> http://www.schmarder.com/radios/crystal/26.htm
>
> Hi Dave,
> My point was, the purists would shudder at the thought of an external
> power source on a crystal radio. Now if you extract the power from a strong
> local and use that to amplify a weak signal then your doing good work.
> Mike
>
>

The tube isn't being used as an amplifier, it's diode is used as a
switchable option to a SS diode. The battery is for it's filament.

"Don Bowey" <(E-Mail Removed)> wrote in message
news:C3FBEB75.B1D97%(E-Mail Removed)...
> On 3/11/08 5:15 AM, in article 91512$47d674c2$18d6b40c$(E-Mail Removed),
> "amdx" <(E-Mail Removed)> wrote:
>
>>
>> "Dave.H" <(E-Mail Removed)> wrote in message
>> news:039c2b9f-720f-49b2-ac76-(E-Mail Removed)...
>>> On Mar 11, 6:05 am, "amdx" <a...@knology.net> wrote:
>>>
>>> *and what's this stuff about a D cell on a crystal radio :-)
>>>
>>> I got the idea from one of Dave Schmarder's radios, #26
>>>
>>> http://www.schmarder.com/radios/crystal/26.htm
>>
>> Hi Dave,
>> My point was, the purists would shudder at the thought of an external
>> power source on a crystal radio. Now if you extract the power from a
>> strong
>> local and use that to amplify a weak signal then your doing good work.
>> Mike
>>
>>
>
> The tube isn't being used as an amplifier, it's diode is used as a
> switchable option to a SS diode. The battery is for it's filament.

Ok then, the purists would shudder at the thought of an external
power source on a crystal radio. Now if you extract the power from a strong
local and use that to bias your diode then your doing good work.
Gees Don, your acting like Phil but without the name calling :-)
Mike


>

"Dave.H" <(E-Mail Removed)> writes:

>On Mar 10, 11:03 am, "Dave.H" <the19...@googlemail.com> wrote:
>> I've been looking at a number of simple crystal radio designs, and
>> I've found the Australian mystery crystal set, and am interested in
>> building that, mainly because it's an Australian design, and I've
>> heard it it's a pretty good performer. I only have 2 questions- can I
>> substitute the detector for a 1N34? and what is double silk covered
>> wire and do I really have use that? What's wrong with regular coil
>> wire? I can only find 23 SWG, 25 SWG, and 33 SWG where I need 24 SWG,
>> 30 SWG.
>>
>> Thanks
>>
>> Dave

>Forgot to give the schematic
>http://www.clarion.org.au/crystalset/mystery.html

Substitutes will work fine. All the other stuff is to make it look like
a "period piece." Go to a rock shop and get some galena for the detector
if you want to go retro.

Steve.
--
Steven D. Swift, (E-Mail Removed), http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

On 3/11/08 3:51 PM, in article 47475$47d70c71$45013908$(E-Mail Removed),
"amdx" <(E-Mail Removed)> wrote:

>
> "Don Bowey" <(E-Mail Removed)> wrote in message
> news:C3FBEB75.B1D97%(E-Mail Removed)...
>> On 3/11/08 5:15 AM, in article 91512$47d674c2$18d6b40c$(E-Mail Removed),
>> "amdx" <(E-Mail Removed)> wrote:
>>
>>>
>>> "Dave.H" <(E-Mail Removed)> wrote in message
>>> news:039c2b9f-720f-49b2-ac76-(E-Mail Removed)...
>>>> On Mar 11, 6:05 am, "amdx" <a...@knology.net> wrote:
>>>>
>>>> *and what's this stuff about a D cell on a crystal radio :-)
>>>>
>>>> I got the idea from one of Dave Schmarder's radios, #26
>>>>
>>>> http://www.schmarder.com/radios/crystal/26.htm
>>>
>>> Hi Dave,
>>> My point was, the purists would shudder at the thought of an external
>>> power source on a crystal radio. Now if you extract the power from a
>>> strong
>>> local and use that to amplify a weak signal then your doing good work.
>>> Mike
>>>
>>>
>>
>> The tube isn't being used as an amplifier, it's diode is used as a
>> switchable option to a SS diode. The battery is for it's filament.
>
> Ok then, the purists would shudder at the thought of an external
> power source on a crystal radio. Now if you extract the power from a strong
> local and use that to bias your diode then your doing good work.
> Gees Don, your acting like Phil but without the name calling :-)
> Mike


Geez Mike, why didn't you take time to see what the OP was doing?

If you wish to really be a purist you should insist one should use a coherer
for the detector, or a chunk of galena and a cats-whisker.

I think it's a bit cool to have two different detectors and be able to
switch between them, like in the good old days.