On Tue, 24 Aug 2004 12:48:29 -0700, Roy Lewallen
wrote:

Without going through the numbers in detail, Paul, OH3LWR's analysis
looks sound. However, he neglected one factor. The skin depth is also
inversely proportional to the square root of the permeability. Some
stainless steels are ferromagnetic, with a permeability I'd guess at 100
or more. That reduces the skin depth, and therefore increases the RF
resistance, by at least a factor of 10.

My skin depth figures are base upon a quick web search, so I have no
idea how typical these figures might be or is it likely that the OP
would have a similar wire.

If you do the analysis with
realistic numbers, you'll find that loss can become at least several dB
if the wire is magnetic, and worse with longer (40 or 80 meter) dipole
lengths.

If my original assumptions are correct, the original poster (OP)
should also check the dissipation of each meter of antenna conductor,
since above 1.8 MHz, it appears that the power dissipation per meter
is slightly higher than at 1.8 MHz, thus the wire temperature is
higher (and might even affect the sag of the wire when
transmitting:-).

So my recommendation is to check the wire with a magnet. If it's
magnetic, expect longer antennas to be quiet and broadband (which
amateurs crave) but lossy (which most don't seem to care about).
Non-magnetic stainless isn't likely to produce objectionable loss,
except perhaps at an 80 meter dipole length or longer.

In addition, since the OP had a large quantity of the wire, I would
suggest building a conical dipole antenna from the wire. Not only will
the current (and losses) in each leg be lower, but also the bandwidth
would be larger.

Paul OH3LWR