Where get short length of fine enamelled wire in UK?

K

Karen

Guest
Where can I get a small spool of fne enamalled copper wire? I'm in
the UK and want about 25metres of single strand of enamelled wire.

Most big dealers sell no less than 250g/8 oz but that's way too long
for me! These are the sort of diameters.

SWG 40 (.0048) = 36or37 AWG
SWG 38 (.0060) = 34or34 AWG
SWG 36 (.0076) = 32or33 AWG big thick

The wire is for a body-worn covert mic and the wire will be twisted
into a par.

A light-brown low-gloss outer would be ideal for camouflaging the wire
but I suspect it doesn't exist. :-(
 
Karen <noone@nowhere.com> wrote in news:Xns9BC99F6C5E8FB451E7A@news-
3.octanews.net:

Where can I get a small spool of fne enamalled copper wire? I'm in
the UK and want about 25metres of single strand of enamelled wire.

Most big dealers sell no less than 250g/8 oz but that's way too long
for me! These are the sort of diameters.

SWG 40 (.0048) = 36or37 AWG
SWG 38 (.0060) = 34or34 AWG
SWG 36 (.0076) = 32or33 AWG big thick

The wire is for a body-worn covert mic and the wire will be twisted
into a par.

A light-brown low-gloss outer would be ideal for camouflaging the wire
but I suspect it doesn't exist. :-(
Click to expand...
eBay might work. I've found it good for small and unusual finds. Better, for
this, might be salvaged relays, solenoids and small AC or DC motors, tape
head demagnetisers... any kind of electromagnet coil. Colours vary more than
you'll likely find in commercial outlets. I've even seen dark blue, but never
seen it on sale. Salvage is good though, you'll find a wide range of colours
similar to human hair colours, some too bright but some near ideal. And free,
and in useful amounts. A small hacksaw, a screwdriver, and a pair of pliers,
might be all the tools you need to get at them. Getting a look at them is
even easier.
 
On Tue 10Mar 05:40, Lostgallifreyan <no-one@nowhere.net> wrote

Karen <noone@nowhere.com> wrote in
news:Xns9BC99F6C5E8FB451E7A@news- 3.octanews.net:

Where can I get a small spool of fne enamalled copper wire? I'm
in the UK and want about 25metres of single strand of enamelled
wire.

Most big dealers sell no less than 250g/8 oz but that's way too
long for me! These are the sort of diameters.

SWG 40 (.0048) = 36or37 AWG
SWG 38 (.0060) = 34or34 AWG
SWG 36 (.0076) = 32or33 AWG big thick

The wire is for a body-worn covert mic and the wire will be
twisted into a par.

A light-brown low-gloss outer would be ideal for camouflaging
the wire but I suspect it doesn't exist. :-(


eBay might work. I've found it good for small and unusual finds.
Better, for this, might be salvaged relays, solenoids and small
AC or DC motors, tape head demagnetisers... any kind of
electromagnet coil. Colours vary more than you'll likely find in
commercial outlets. I've even seen dark blue, but never seen it
on sale. Salvage is good though, you'll find a wide range of
colours similar to human hair colours, some too bright but some
near ideal. And free, and in useful amounts. A small hacksaw, a
screwdriver, and a pair of pliers, might be all the tools you
need to get at them. Getting a look at them is even easier.
Click to expand...
I'm not really happy about eBay. Salvage might be good but I worry
that I am getting wire with resistence from some transformer.
 
On Wed 11Mar 02:35, Ross Herbert <rherber1@bigpond.net.au> wrote

On Mon, 09 Mar 2009 15:40:18 +1100, Karen <noone@nowhere.com
wrote:

:Where can I get a small spool of fne enamalled copper wire? I'm
:in the UK and want about 25metres of single strand of enamelled
:wire.
:
:Most big dealers sell no less than 250g/8 oz but that's way too
:long for me! These are the sort of diameters.
:
:SWG 40 (.0048) = 36or37 AWG
:SWG 38 (.0060) = 34or34 AWG
:SWG 36 (.0076) = 32or33 AWG big thick
:
:The wire is for a body-worn covert mic and the wire will be
:twisted into a par.
:
:A light-brown low-gloss outer would be ideal for camouflaging the
:wire but I suspect it doesn't exist. :-(


So how do you twist 0.0048" wires into a pair without breaking
it? Even when you do manage it, how do you stop the twisted pair
from breaking due to snagging on clothing while being worn?
Click to expand...

Twisting a pair of SWG 40 wires is not so hard at all. Try it. They
are only a metre long.

You can stick the twisted pair to a garment or to skin every 6 to 8
inches. You can even us a small stitch on a garment of about 3mm
(each wire done separately in a needle). Trouble is the small 3mm
visible section sparkles too much and would be noticed.

If it the wires break when they're removed then that's no big deal
because they can be replaced.

My thinking is that it's a good thing if the pair break relatively
easily. You might get challenged with a question if "that" is a
mic, and in response you could then pull it away, breaking the
wires and display it is unattached. It's not foolproof but might be
better than having no reply.

Anyway, I'm looking for a source that doesn't sell me over a mile
of the stuff in a 250 grams reel.
 
Hi Karen,

I'm sure I can help if you care to contact me directly by e-mail.

- Dave

In article <Xns9BC99F6C5E8FB451E7A@news-3.octanews.net>, Karen
<noone@nowhere.com> writes
Where can I get a small spool of fne enamalled copper wire? I'm in
the UK and want about 25metres of single strand of enamelled wire.

Most big dealers sell no less than 250g/8 oz but that's way too long
for me! These are the sort of diameters.

SWG 40 (.0048) = 36or37 AWG
SWG 38 (.0060) = 34or34 AWG
SWG 36 (.0076) = 32or33 AWG big thick

The wire is for a body-worn covert mic and the wire will be twisted
into a par.

A light-brown low-gloss outer would be ideal for camouflaging the wire
but I suspect it doesn't exist. :-(
Click to expand...
--
David C.Chapman - Chartered Engineer. FIET. (dcchapman@minda.co.uk)
--------------------------------------------------------------------------
CHAPMAN ASSOCIATES is a Consultancy offering practical expertise and
design skills in the fields of counter-surveillance, electronic protection
and security. Visit our Web site at http://www.minda.co.uk
--------------------------------------------------------------------------
 
On Mon, 09 Mar 2009 15:40:18 +1100, Karen <noone@nowhere.com> wrote:

:Where can I get a small spool of fne enamalled copper wire? I'm in
:the UK and want about 25metres of single strand of enamelled wire.
:
:Most big dealers sell no less than 250g/8 oz but that's way too long
:for me! These are the sort of diameters.
:
:SWG 40 (.0048) = 36or37 AWG
:SWG 38 (.0060) = 34or34 AWG
:SWG 36 (.0076) = 32or33 AWG big thick
:
:The wire is for a body-worn covert mic and the wire will be twisted
:into a par.
:
:A light-brown low-gloss outer would be ideal for camouflaging the wire
:but I suspect it doesn't exist. :-(


So how do you twist 0.0048" wires into a pair without breaking it? Even when you
do manage it, how do you stop the twisted pair from breaking due to snagging on
clothing while being worn?
 
Anyway, I'm looking for a source that doesn't sell me over a mile
of the stuff in a 250 grams reel.
Click to expand...
How much does a 250 gram reel cost?

Last time I looked for wire, all the different sizes and colors
were sold in the same size spools with the same weight. So
for tiny wire, you are going to get a lot of it if you measure
length rather than weight. I doubt if any of the normal wire
sources will have anything smaller.

--
These are my opinions, not necessarily my employer's. I hate spam.
 
Karen <noone@nowhere.com> wrote in
news:Xns9BCA9D0E245ED451E7A@204.153.245.22:

I'm not really happy about eBay. Salvage might be good but I worry
that I am getting wire with resistence from some transformer.
Click to expand...
It's copper. :) How much resistance can there be? it will be fine. Whatever
source of copper wire you use, there will be some resistance, but not enough
to be a problem. More important is to use a balanced line input, i.e. a
differential amplifier, so noise picked up on the twisted pair will cancel,
leaving the sound signal you want intact.
 
Karen <noone@nowhere.com> wrote in
news:Xns9BCA9FF4EC305451E7A@204.153.245.20:

Trouble is the small 3mm
visible section sparkles too much and would be noticed.
Click to expand...
once you have made the twisted pair, try getting some matt varnish in a small
brush and running the wire through the bristles. Once it dries it will be
less shiny, especially if you draw it through a gently folded cloth while
it's still tacky, ideally the same cloth you'll be using, so any fibres that
stick to it will help camouflage it.
 
Lostgallifreyan <no-one@nowhere.net> wrote in
news:Xns9BCB9E5CB7923zoodlewurdle@216.196.109.145:

Trouble is the small 3mm
visible section sparkles too much and would be noticed.

once you have made the twisted pair, try getting some matt varnish in a
small brush and running the wire through the bristles. Once it dries it
will be less shiny, especially if you draw it through a gently folded
cloth while it's still tacky, ideally the same cloth you'll be using, so
any fibres that stick to it will help camouflage it.
Click to expand...
While you're at it, twist it with a thin strong thread to give it strength
and further help with camouflage and varnish retention.
 
On Wed 11Mar 15:30, Lostgallifreyan <no-one@nowhere.net> wrote

Karen <noone@nowhere.com> wrote in
news:Xns9BCA9D0E245ED451E7A@204.153.245.22:

I'm not really happy about eBay. Salvage might be good but I
worry that I am getting wire with resistence from some
transformer.


It's copper. :) How much resistance can there be? it will be
fine. Whatever source of copper wire you use, there will be some
resistance, but not enough to be a problem. More important is to
use a balanced line input, i.e. a differential amplifier, so
noise picked up on the twisted pair will cancel, leaving the
sound signal you want intact.
Click to expand...
What I meant was that a transformer may have an impedance of 50K and I
don't want that wire because I assume the wire is made in a way to
give extra resistence.

Good point about the two wires needing to be balanced. I remembered a
discussion which started by saying the twisted pair would have to be
balanced then someone else said try it without. I'll see what happens!

My recorder has unbalanced inputs and I would rather not get some
device to put between amp & mic.
 
On Wed 11Mar 15:34, Lostgallifreyan <no-one@nowhere.net> wrote

Karen <noone@nowhere.com> wrote in
news:Xns9BCA9FF4EC305451E7A@204.153.245.20:

Trouble is the small 3mm
visible section sparkles too much and would be noticed.

once you have made the twisted pair, try getting some matt
varnish in a small brush and running the wire through the
bristles. Once it dries it will be less shiny, especially if you
draw it through a gently folded cloth while it's still tacky,
ideally the same cloth you'll be using, so any fibres that stick
to it will help camouflage it.
Click to expand...

Oh! That is creative.

Not sure how easy it will be to leave a suitable film of varnish or if
the varnish can be flexed when dry but it has to be worth a try. I
wonder if soft-hold hair lacquer is another way to do this.

You seem to have a good feel for what I am trying to do. Have you got
experience of covert recording? :)
 
Karen wrote:
What I meant was that a transformer may have an impedance of 50K and I
don't want that wire because I assume the wire is made in a way to
give extra resistence.
Click to expand...

You are confusing impedance with resistance. The DC resistance of
that 50k winding is much lower.




--
http://improve-usenet.org/index.html

Goggle Groups, and Web TV users must request to be white listed, or I
will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
 
Karen <noone@nowhere.com> wrote in news:Xns9BCBE4A4B3268451E7A@news-
3.octanews.net:

What I meant was that a transformer may have an impedance of 50K and I
don't want that wire because I assume the wire is made in a way to
give extra resistence.
Click to expand...
It's ok, they just wind enough windings on them to get those ratings, bearing
in mind the characteristics of the core as well. The only reason to avoid
transformers is they're sods to unwind. Solenoids, demagnetisers, relay
coils, are all neat bobbins you can unreel wire off as easily as if you'd
bought it ready wrapped, so long as you cut the bobbin free of any
containment without damage.

Re balanced, try it WITH first. :) It's just as easy to build a differential
amp from op-amps as a single input type, you just configure the resistors
differently, and they're all standard circuits. Unless your wires to the mic
are less than about an inch long, you really need that noise cancellation
that a diff amp gives.

Despite your recorder having only unbalanced inputs, you might get away with
it so long as you don't refer to any ground, only to the chassis or local
ground inside it. If you use an electret mic (smaller than dynamic) the FET
in it will put out a voltage high enough to help with signal to noise ratio
even over an unshielded twisted pair. It won't be hi-fi but it will be
useable. You can remove constant noise later with a digital editor too (the
kind that take a noise print, so if you use one, record some noise on its
own as sample).
 
Karen <noone@nowhere.com> wrote in news:Xns9BCBE4AABFBD9451E7A@news-
3.octanews.net:

On Wed 11Mar 15:34, Lostgallifreyan <no-one@nowhere.net> wrote

Karen <noone@nowhere.com> wrote in
news:Xns9BCA9FF4EC305451E7A@204.153.245.20:

Trouble is the small 3mm
visible section sparkles too much and would be noticed.

once you have made the twisted pair, try getting some matt
varnish in a small brush and running the wire through the
bristles. Once it dries it will be less shiny, especially if you
draw it through a gently folded cloth while it's still tacky,
ideally the same cloth you'll be using, so any fibres that stick
to it will help camouflage it.


Oh! That is creative.

Not sure how easy it will be to leave a suitable film of varnish or if
the varnish can be flexed when dry but it has to be worth a try. I
wonder if soft-hold hair lacquer is another way to do this.

You seem to have a good feel for what I am trying to do. Have you got
experience of covert recording? :)
Click to expand...
Nope, but it's an interesting problem. Polyurethane varnish should be ok, it
stays flexible for months.. Soft hold hair laquer I don't know about, but it
does make me think of the smells of such things as opposed to those of
varnishes. It's worth experimenting with stuff that smells like it will be
far less out of place than a woodworking varnish kind of smell, if it's to
stay un-noticed and be used soon after preparation. Irrelevent, maybe, unless
you're going to be in a small unventilated room.
 
My offer to help is STILL available if you care to contact me
directly. I have some very thin TWO-core enamelled wire that will do
the job perfectly for you.

- Dave

--
David C.Chapman - Chartered Engineer. FIET. (dcchapman@minda.co.uk)
--------------------------------------------------------------------------
CHAPMAN ASSOCIATES is a Consultancy offering practical expertise and
design skills in the fields of counter-surveillance, electronic protection
and security. Visit our Web site at http://www.minda.co.uk
--------------------------------------------------------------------------
 
On Thu 12Mar 12:28, David Chapman <dave@minda.co.uk> wrote:
My offer to help is STILL available if you care to contact me
directly. I have some very thin TWO-core enamelled wire that will do
the job perfectly for you.

- Dave
Click to expand...
Hi Dave, sorry I didn't get back to you before. I wasn't sure you were
really serious about letting me have some wire.

Email sent.

K
 
On Thu 12Mar 01:11, Lostgallifreyan <no-one@nowhere.net> wrote:
Karen <noone@nowhere.com> wrote:

What I meant was that a transformer may have an impedance of 50K
and I don't want that wire because I assume the wire is made in a
way to give extra resistence.


[trimmed]

Re balanced, try it WITH first. :) It's just as easy to build a
differential amp from op-amps as a single input type, you just
configure the resistors differently, and they're all standard
circuits. Unless your wires to the mic are less than about an inch
long, you really need that noise cancellation that a diff amp
gives.

Despite your recorder having only unbalanced inputs, you might get
away with it so long as you don't refer to any ground, only to the
chassis or local ground inside it. If you use an electret mic
(smaller than dynamic) the FET in it will put out a voltage high
enough to help with signal to noise ratio even over an unshielded
twisted pair. It won't be hi-fi but it will be useable. You can
remove constant noise later with a digital editor too (the kind
that take a noise print, so if you use one, record some noise on
its own as sample).
Click to expand...

Hello Lostgallifreyan, your post contains a lot of info and much of it
intrigues me. Can I break into parts.

You say "it's just as easy to build a differential amp from op-amps as
a single input type, you just configure the resistors differently".
The mic capsule will be an electret and I was going experiment with (a)
an electret mic with two contacts and (b) an electret mic with three
contacts.

I was just going to put the mic capsule in place and run the two
twisted fine wires to the input of the recorder. In the case of the
three wire capsule I would add a resistor between 2 leads (as advised
by the manufacturer) to convert it to two wire operation.

I wasn't going to build any amplifier! This is a little bit out of my
depth. I was just going to plug the mic. However, now that you have
mentioned amps can you point me in the direction of a circuit or web
page which might show more detail of the sort of thing you mean.

I would like to avoid removing noise because when I have tried that
using an audio editor using a noise sample from a non-speaking part of
the recording, I found the speech quality suffered a bit too much.

As background, one particular three wire capsule I have in mind is the
micro-sized Knowles FG. http://tinyurl.com/bbdzg5 (I am in the UK.)

This FG-23329-P07 capsule is prewired with 3-wires (positive, negative,
output, and also a shield wire from the case. It is in the chart on
page 9 of Knowles's Design Guide:
<www.knowles.com/search/pdf/07-KA-895_designguide_final_v1.pdf>

Thank you or anyone else for any info.

K
 
Karen <noone@nowhere.com> wrote in
news:Xns9BCEAB381467C451E7A@text.news.virginmedia.com:

Hello Lostgallifreyan, your post contains a lot of info and much of it
intrigues me. Can I break into parts.

You say "it's just as easy to build a differential amp from op-amps as
a single input type, you just configure the resistors differently".
The mic capsule will be an electret and I was going experiment with (a)
an electret mic with two contacts and (b) an electret mic with three
contacts.

I was just going to put the mic capsule in place and run the two
twisted fine wires to the input of the recorder. In the case of the
three wire capsule I would add a resistor between 2 leads (as advised
by the manufacturer) to convert it to two wire operation.
Click to expand...
I tried Googling for advantages to be had from 3-terminal electrets, and it
could take hours or days to find out that way, so it might be best to just go
with a 2-terminal scheme by modifying as you describe if needed, for a 3-
terminal capsule. If there WAS any significant advantage to 3 terminals, it
would be a lot easier to find examples than it is now. I couldn't find one at
all that wasn't explaining how to convert to two.

I wasn't going to build any amplifier! This is a little bit out of my
depth. I was just going to plug the mic. However, now that you have
mentioned amps can you point me in the direction of a circuit or web
page which might show more detail of the sort of thing you mean.
Click to expand...
You will need to provide power to the mic capsule somehow, so either
modifying the internal circuit in the recorder, or adding something outside
it. Most times, the second choice is better, unless you really want a
permanent mod to the recorder.

http://www.apogeekits.com/spy_equipment.htm shows a small kit, which might be
the best way to go. That way most of the work is done, but modification is
easy, and you can devise your own housing, for best discretion.

http://users.rcn.com/rhcamp is a good page for info, and likely a way to buy
a built circuit. They're very small.

For circuits for building yourself, http://www.g3vfp.org/files/micpreamp.gif
or http://sound.westhost.com/projects-8a.htm have some ideas.

I would like to avoid removing noise because when I have tried that
using an audio editor using a noise sample from a non-speaking part of
the recording, I found the speech quality suffered a bit too much.
Click to expand...
Takes practise.. :) Ideally, use a small analysis window size, and reduce by
no more than 24 dB unless the noise is VERY constant and smooth, in which
case try for up to 35 dB reduction. As an example, if you get the Sonic
Foundry version 2 noise reduction plugin, set for mode 3 (of 0~3), and tweak
the noise bias in conjunction with the reduction control, it should be easy
to get very clean results. After NR you can apply an 'Aural Exciter' or
smilar tool (Hyperprism do one, as do Aphex) to build on the HF part of the
signal. This is seriously cool, well worth doing, it increases
intelligibility enormously. (I used it on recordings from FM as well as
sounds used in music making).

As background, one particular three wire capsule I have in mind is the
micro-sized Knowles FG. http://tinyurl.com/bbdzg5 (I am in the UK.)

This FG-23329-P07 capsule is prewired with 3-wires (positive, negative,
output, and also a shield wire from the case. It is in the chart on
page 9 of Knowles's Design Guide:
www.knowles.com/search/pdf/07-KA-895_designguide_final_v1.pdf
Click to expand...
Some neat mics shown in that PDF! Not sure which is best, but I remember
reading about a Lavalier mic system using a tiny Panasonic capsule and a
simple preamp. Lavalier is a good key to searching because it implies a long
wire between a tiny capsule and the main amp. Most use a sheilded cable but
twisted pairs do get mentioned.

I think the thing to do is try one of the simpler ideas I liked to, as the
mics aren't balanced, so you can just use a low noise op-amp IC. If you get
too much noise, consider some of the more elaborate ones, especially those
that use a small inductor on the preamp input.
 
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