In a message dated 11/29/2006 6:20:36 P.M. Greenwich Standard Time,
clive.whelan@btinternet.com writes:
Not sure if it's relevant, but I discovered to my cost when
making a 21Mhz Moxon that typical PVC insulated wire will
exhibit a "velocity factor", and ends up 3 to 4% long. This
may not be very significant for say an 80m dipole, but sure
as hell is for a 21Mhz wire yagi. In the end I used bare
wire.
I don't know your house wire, but almost certainly it is
soft drawn. and WILL stretch under tension. How much and for
how long? Think of a number.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That 3-4% is what I found too when I constructed my 4 el quad for 80. The
"fudge factor came in to play. However, I liked using the insulated wire
since it exhibited no noise from rain static.
Bill K4XS/KH6
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