BB8R3 Antenna project (posted date: 24'th of December 2015 )
Shortened multiband antenna for urban use There are three bands for the moment 3.6/7.1/10.1 MHz for the PSK digital modes. All three for only one 50 Ohms feed point. The project is intended to extends from three to eight bands all for a very limited deployment area space. BB-8 name was inspired by the funny/weird robot from Star Wars. Below one can try the source code written for the 4NEC2.
CM My BB8R3 antenna - Shortened Inverted Vee three-band fan dipole
CM YO5OUC - Nicolae Crisan
CM Three-band antenna
CM 3.6 MHz/7.1 MHz and 10.1 MHz for PSK digital modes
CM Lenght = 24 m
CM
CM
CM
CE
SY l1=10.9
SY l2=1.5 'distance from the end to the load L
SY alfa=60 'half of the tip angle
SY h=20 'distance from the ground
SY l3=0.3
SY l4=0.2
SY L=106e-6
SY l5=7.2
GW 1 11 -l3/2 0 h -l1*sin(alfa)-l3/2 0 h-l1*cos(alfa) 0.002
GW 2 11 l3/2 0 h l1*sin(alfa)+l3/2 0 h-l1*cos(alfa) 0.002
GW 3 1 -l3/2 0 h l3/2 0 h 0.002
GW 4 1 -l1*sin(alfa)-l3/2 0 h-l1*cos(alfa) -l1*sin(alfa)-l3/2-l4*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa) 0.002
GW 5 1 l1*sin(alfa)+l3/2 0 h-l1*cos(alfa) l1*sin(alfa)+l3/2+l4*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa) 0.002
GW 6 3 -l1*sin(alfa)-l3/2-l4*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa) -l1*sin(alfa)-l3/2-l4*sin(alfa)-l2*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa)-l2*cos(alfa) 0.002
GW 7 3 l1*sin(alfa)+l3/2+l4*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa) l1*sin(alfa)+l3/2+l4*sin(alfa)+l2*sin(alfa) 0 h-l1*cos(alfa)-l4*cos(alfa)-l2*cos(alfa) 0.002
GW 8 9 -l3/2 0 h -l3/2 -l5*sin(alfa)-l3/2 h-l5*cos(alfa) 0.002
GW 9 9 l3/2 0 h l3/2 l5*sin(alfa)-l3/2 h-l5*cos(alfa) 0.002
GE 1
LD 0 4 1 1 6 L 0
LD 0 5 1 1 6 L 0
GN 2 0 0 0 3 0.0001
EK
EX 0 3 1 0 1 0 0
FR 0 0 0 0 10.1 0
EN