On Thu, 07 Jun 2007 13:11:38 -0700, Andrea wrote:

Thanks Richard.
Do you know if there is a formula to calculare the max power that a
wire can supports?

Hi Andrea,

No. Not off-hand. I use "wire tables" to reference what is called
"fuse current." This is the current that will burn a wire open. For
a 1mm wire, that would be around 50 to 80 Amperes. Your antenna would
have to be a very small loop to encounter that kind of current. Very
small means less than 0.1 wavelength in diameter. You would encounter
other problems long before the wire would melt.

73's
Richard Clark, KB7QHC

Richard Clark wrote in
:

On Thu, 07 Jun 2007 13:11:38 -0700, Andrea wrote:

Thanks Richard.
Do you know if there is a formula to calculare the max power that a
wire can supports?

Hi Andrea,

No. Not off-hand. I use "wire tables" to reference what is called
"fuse current." This is the current that will burn a wire open. For

Are those tables based on the DC resistance or low frequency AC resistance
of the wire?

If so, are they relevant to rating the wire for current handling capacity
at RF where for example skin effect increases the dissipation for a given
current?

Owen

On Fri, 08 Jun 2007 06:27:13 GMT, Owen Duffy wrote:

If so, are they relevant to rating the wire for current handling capacity
at RF where for example skin effect increases the dissipation for a given
current?

Hi Owen,

Really, a 1mm wire is sufficient for a 100W transmitter in a long wire
antenna application. There is no need to elaborate.

73's
Richard Clark, KB7QHC

Richard Clark wrote:

...

Richard Clark, KB7QHC

Richard:

I should think I could probably power a 100 watt light bulb though a 1mm
wire. Perhaps a 150 watt one?

At 200 watts, I'd more than expect the wire to be getting rather warm,
even with enamel insulation and in free space ...

At a KW, I'd expect to be breathing some copper ions/particles!

JS

John Smith I wrote:

[stuff]

In the previous post, 1 mm wire is #18 gauge AWG. (#12 = ~2 mm)

And, every 6 gauge decrease results in a doubling of the wires diameter,
every 3 gauge decrease results in a doubling of the wires cross
section--just as for db in signal levels ...

JS

John Smith I wrote:

Further, I meant to point out that 100% skin depth only occurs to
~17Khz. And, while #18 may be ok for a max of 16 amps when used in
chassis wiring, it is only rated at ~2.3 amps for power transmission ...

Anyone know how many amps commonly flow through a current node on a 1/4
or 1/2 wave ant? Now, that's the real question, isn't it? And, if all
that power is all concentrated in just the skin of the copper, wouldn't
there be a degradation of power handling directly related to frequency?

Regards,
JS

John Smith I wrote:
Anyone know how many amps commonly flow through a current node on a 1/4
or 1/2 wave ant? Now, that's the real question, isn't it?

John, you should be talking about the current anti-node,
i.e. the current maximum, not the current node (minimum).
For a 1/2WL center-fed dipole or a 1/4WL monopole, the
current is maximum at the feedpoint which is easy to
calculate, e.g. 1.414 amps for 100 watts into 50 ohms.
--
73, Cecil http://www.w5dxp.com

On 8 Jun, 11:20, Richard Clark wrote:
On Fri, 08 Jun 2007 06:27:13 GMT, Owen Duffy wrote:
If so, are they relevant to rating the wire for current handling capacity
at RF where for example skin effect increases the dissipation for a given
current?

Hi Owen,

Really, a 1mm wire is sufficient for a 100W transmitter in a long wire
antenna application. There is no need to elaborate.

73's
Richard Clark, KB7QHC

Sorry Owen, you have been censored.

the answer makes prefect sense professor!

On Jun 8, 12:00 pm, art wrote:
On 8 Jun, 11:20, Richard Clark wrote:

On Fri, 08 Jun 2007 06:27:13 GMT, Owen Duffy wrote:
If so, are they relevant to rating the wire for current handling capacity
at RF where for example skin effect increases the dissipation for a given
current?

Hi Owen,

Really, a 1mm wire is sufficient for a 100W transmitter in a long wire
antenna application. There is no need to elaborate.

73's
Richard Clark, KB7QHC

Sorry Owen, you have been censored.