Topband: Feeding vertical

[Dan Zimmerman N3OX]

A simple L-network should have very modest-value components to match
this thing on 160.  I assume the towers are 1/4 wavelength (280 feet)
at 870KHz.

A very wild guess for the impedance on 1.8MHz based on a 280 foot
radiator 24 inches in "diameter" might be 500-j500.  If so, an L
network to match to 50 ohms would have a 16 microhenry inductor
between antenna feedpoint and ground and a series cap of about 400pF.
Not very hard to come by.

Of course, these values aren't worth much aside from a possible
starting point for experimentation to find a match.  The actual
impedance of the tower on 160m could be all over the place depending
on face width and exact height and so forth.


73,
Dan