In article ,
Spehro Pefhany wrote:

You might be able to do it with a vernier caliper.

24 gauge has a diameter of .511 mm or .0020"

30 gauge has a diameter of .255 mm or .001"

Ooops, you're low by a factor of 10:1 in the inch calculations. Just
as well, since a caliper is hardly repeatable to 1 thou, let alone
measuring a diameter of that size with any accuracy.

Yup, I added a zero in there. 24 gauge is 20 mils (.02"), 30 gauge is
half that.

Works out to 50 or 100 turns per inch, close-wound, and the suggestion
to use that method was probably the best and cheapest I've heard.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Which gauge are you using?

British Standard wire gauge (SWG) ?
American wire gauge (AWG) ?
Birmingham wire gauge (BWG) ?

They're all different.

I read in sci.electronics.design that Reg Edwards
wrote (in
) about 'wire size question', on Thu,
7 Apr 2005:
Which gauge are you using?

British Standard wire gauge (SWG) ? American wire gauge (AWG) ?
Birmingham wire gauge (BWG) ?

Malt vinegar gauge - brown and sharp. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

What wire gauge, if one at all, do metricated industrial countries
use?

France, Germany, Russia, China, for example.

I read in sci.electronics.design that Reg Edwards
wrote (in
) about 'wire size question', on Sun,
10 Apr 2005:
What wire gauge, if one at all, do metricated industrial countries
use?

France, Germany, Russia, China, for example.


There is an IEC standard, IEC 60317-0-1, which specifies a range of
metric diameters for enamelled copper winding wires.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

"Reg Edwards" writes:

Which gauge are you using?

British Standard wire gauge (SWG) ?
American wire gauge (AWG) ?
Birmingham wire gauge (BWG) ?
Navy Gauge?

{I recall US Navy had some scheme that was its alone; sizes were
directly proportional to label...}


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Dave Platt" wrote in message
...
Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire
and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

A cautionary note - if it's that critical, then re-using wire which
has alread been wound might not be the best idea. You'd be starting
with wire which had already been bent/flexed, and if you aren't
careful this might put some kinks or irregularities in the winding of
your new coil which might affect its impedance or Q.

I know I can weigh it, provided it's not on a spool or motor winding
already.

My local electrical shop has a wire gauge, but it stops at 18 gauge.

A microscope might work, but ones that have calibrated distance
measuring on the eyepiece are expensive.

You might be able to do it with a vernier caliper.

24 gauge has a diameter of .511 mm or .0020"

30 gauge has a diameter of .255 mm or .001"

Man, are you _way_ off! By an order of magnitude! Put your glass on
and reread the wire tables.

Every 3 gauge numbers corresponds to a 2:1 ratio in wire area (amount
of copper). Every 6 gauge numbers corresponds to a 2:1 ratio in wire
diameter.

--
Dave Platt
AE6EO
Hosting the Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Thu, 07 Apr 2005 17:29:15 -0400, Albert wrote:

Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

I know I can weigh it, provided it's not on a spool or motor winding
already.

My local electrical shop has a wire gauge, but it stops at 18 gauge.

A microscope might work, but ones that have calibrated distance
measuring on the eyepiece are expensive.

Perhaps a milliohm meter might be able to measure the difference in
resistance of a foot of it or so, but that's hardly a standard item
either.

Any suggestions?

Two quick options:

Many kinds of wire have information printed on the insulation.

There are many tables which give the diameter, so machinists verniers
or a mike would do.

Or you could collect a set of samples of known wires and compare. Note
that solid and stranded are a little bit different.

Recycling solid wire from other coils might leave kinks or weak areas
where it was bent before. Insulation integrity matters, too.
Happy trails,
Gary (net.yogi.bear)
--
At the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

Get a nice piece of smooth round rod and tightly wind a little over a lineal
inch of wire closely spaced as possible. Count the turns in one inch and
divide the number of turns into one inch and you'll have a very good
measurement without any cost.

73
Hank WD5JFR

Albert wrote in message ...
Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

I know I can weigh it, provided it's not on a spool or motor winding
already.

My local electrical shop has a wire gauge, but it stops at 18 gauge.

A microscope might work, but ones that have calibrated distance
measuring on the eyepiece are expensive.

Perhaps a milliohm meter might be able to measure the difference in
resistance of a foot of it or so, but that's hardly a standard item
either.

Any suggestions?

Thanks,

A

From: "Henry Kolesnik" on Thurs,Apr 7 2005 10:15 pm

Get a nice piece of smooth round rod and tightly wind a little over a
lineal
inch of wire closely spaced as possible. Count the turns in one inch
and
divide the number of turns into one inch and you'll have a very good
measurement without any cost.

73
Hank WD5JFR

Albert wrote in message
...
Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire
and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

I know I can weigh it, provided it's not on a spool or motor winding
already.

My local electrical shop has a wire gauge, but it stops at 18 gauge.

A microscope might work, but ones that have calibrated distance
measuring on the eyepiece are expensive.

Perhaps a milliohm meter might be able to measure the difference in
resistance of a foot of it or so, but that's hardly a standard item
either.

Any suggestions?

A non-destructive measurement is best. Along about
1946 my middle school (we called it "junior high" back
then) electric shop instructor demonstrated how to use
a mechanical caliper and how NOT to squeeze too hard in
doing so. Soft-drawn copper common to wire is fairly
easy to squash when using a caliper. Using one requires
a VERY light touch on the wire, just enough to be able
to pull it slightly through the caliper jaws. Even so,
pulling on soft-drawn copper wire is going to distort it
slightly so the measurement is going to be on the small
side. Snipping off ten or twenty short lengths, then
measuring the total width and dividing by the number of
lengths will be a bit better in accuracy.

A pocket optical comparator is handy for this and other
uses, especially when trying to get a measurement on
something already mounted with epoxy, varnish, etc. as
in windings of electric motors. While the "100-foot
resistance test" is a practical idea with a roll of
wire, it is hard to do when the wire comes from a
motor or transformer giving its all to the project.

As a practical matter, the wire size in small (such as
HF range) coils won't matter much on either the
inductance or Q tolerance. For example, Dropping from
30 AWG to 32 AWG isn't going to be a disaster in
cylindrical ("solenoidal") or toroidal forms. The
change in inductance will be aligned-out on trimming
in the circuit itself. Q is going to change much more
depending on the material of the coil former and the
presence of nearby conductive objects such as shields.

If a Twenty is too much for a pound or so of new wire
stock, then nobody can afford a Q Meter or inductance
meter to do an accurate measurement. Get with some
friends/acquaintences and share the cost of new stock.

Just some practical thoughts after doing a bit of
winding in my time...