Topband: half size flag antenna--NW6S

[Jim & Carolyn Kingsbury]

I am interested in building a half size flag antenna (15 ft by 7 ft) to work on 80, 40 30, & 20meters.  The antenna will be rotatable and will be used to augment my vertical xmit antenna.  My question is what is the value of the termination resistor to optimize this antenna.   I will use 75 ohn feed line coax.  Thanks for any help.  73 Jim Kingsbury  nw6s (at) ARRL.net