SL FM Yagi - Opt Gain
Free Space Symmetric
91.500 MHz
12 6061-T6 wires, inches
rfs = -24.5		; org space = -24.50" 
des = 0.00		; org space = 0.00"
drs1 = 11		; org space = 11.00" 
drs2 = 30.25		; opr space = 30.25" 	
drs3 = 40.5		; add space = 40.50"

dia = .392		; 25/64" = 0.392" for Drv + Ref 
dia2 = .375		; 3/8" = 0.375 for Dr1,Dr2,Dr3

rfl = 31.75		; org = 31.813" - 31.75" 
dr1 = 28.5		; org = 28.133" - 28.50" 
dr2 = 28.25		; org = 28.133" - 28.25" 
dr3 = 28		; new 3rd dir   - 28.00" 

len = 27.75		; drv el half-length; org length = 27.75"
sp = 1.824		; drv el upside spacing: c/b = 1.824"
nsp = -1.46		; drv el downside spacing: c/b = -1.46"

 1   0     -len   nsp   0      len   nsp    dia
 1   0     -len   sp    0      len    sp    dia
 1   0     -len   sp    0     -len   nsp    dia
 1   0      len   sp    0      len   nsp    dia

 1   rfs    -rfl   0    rfs     0.0    0    dia
 1   rfs     0.0   0    rfs     rfl    0    dia 
 1   drs1   -dr1   0    drs1    0.0    0    dia2
 1   drs1    0.0   0    drs1    dr1    0    dia2
 1   drs2   -dr2   0    drs2    0.0    0    dia2
 1   drs2    0.0   0    drs2    dr2    0    dia2 
 1   drs3   -dr3   0    drs3    0.0    0    dia2
 1   drs3    0.0   0    drs3    dr3    0    dia2
 1 source
 Wire 1, center

 This antenna was modeled from visual measurements of the Stellar Labs 4el
 FM Antenna as delivered. When optimized using AO, the final specs;
   9.43 db F/G 
   9.41 db F/B
  300 ohm feed impedance- swr due to match; 293 + j 19 
  SWR = 1.07:1

 To receive the FM station from Los Angeles @ 91.5 Mhz - KUSC FM 

 The antenna has a 300 to 75 stripline transformer built into the feed point
 making the transmission line (RG-6) a better way to send the signal to my
 FM tuner. Add three (3) ferrite line chokes (apx 1100 ohms) at the feed 
 point to further attenuate the common mode signal.  
 
 Where I live F/G is more important than F/B ratio b/c of distance to KUSC's
 xmitter site . . .109 miles. Need all the F/G that I can get!