Hello Martin, I have other equations here: www.w0btu.com/bev_ant_impedance-math.html
Other charts, matching transformer ratios, etc. are on www.w0btu.com/Beverage_antennas.html 73, Mike www.w0btu.com On Wed, Jan 24, 2018 at 5:27 AM, Martin <[email protected]> wrote: > Topbanders, > for the construction of the beverage ( a 2 wire reversible beverage, that > is) from my post a few days ago i wanted to know how to measure or > determine the impedance of the open wire. I stumbled across a very simple > method some of of you might know , some might not. Anyway, here is the > method. It works for coaxial cable or open wire. > You need no fancy measurement gear- rule, pocket calculator and LC meter > will do. For really long runs you might need the help of a tape rule or > even google maps. > > Measure the length of the unknown coaxial cable or open wire (DUT Device > under test) in meters m. > > With both ends open, measure capacitance C of DUT, divide it by it's > length ( C' = C/m) . > > Shorten one end, measure inductance of DUT, divide it by length ( L' = > L/m) . > > Now calculate > > Z= 1000 * squareroot(L'/C') > > Voila. > > It may also help to determine if and where your cable or 2 wire beverage > has an intermittance when you already know it's impedance it had before the > failure. Transform the formula accordingly. > I think it should also help to determine the impedance of the beverage ( > single wire or 2 wire) measured against ground(?). > > > -- > > Ohne CW ist es nur CB.. > > 73, Martin DM4iM > ____ > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
