Ralph Mowery wrote:
"Jimmie" Gfender@carolina dot.rr.dot com wrote in message
.com...
I want to make a 2m Yagi out of stainless steel, partly because of the
corrosion resistance but mostly because I have the materials on hand. Some
of my friends have tried to tell me that the higher ohmic resistance of SS
will make for a poor antenna. Frankly I do see that it would make any
significant difference. While SS has several times the resistance of AL I
figure we are just comparing micro ohms to milliohms.at worst, probably
more
like micro ohm to tens of micro ohms. I am a correct on these assumptions
or
should I listen to my friends.
If you have the materials go ahead and make the antenna. SS is just
harder to work with for most people and weighs more. YOu will loose
some gain but unless you are into very weak signal work it will not be
too noticable.
That's correct - especially the last part.
In typical yagi designs, resistive losses in normal aluminum elements
are on the order of a percent - which is negligible. There are many
grades of SS, of course, but again a typical value might be a few
percent.
In Europe there is a successful range of 'Flexa-Yagis' of very
lightweight construction using elements made from thin, springy SS wire.
These yagis are only about 0.5dB down in gain compared with ali elements
at 144MHz, and maybe 1dB at 432MHz.
A few years down the line, when ali elements may have corroded, the SS
elements may even come out ahead.
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek