The Stellar Labs 30-2460 is a four-element Yagi with folded dipole and integral 300Ω balun. The boom length is 1.63 m (64″). The red dot marks the feedpoint.
I modeled the antenna with the AO 9.67 Antenna Optimizer. Calculated performance is for 28 analysis segments per conductor halfwave. Forward gain includes mismatch and conductor losses but excludes balun loss. F/R is the ratio of forward power to that of the worst backlobe in the rear half-plane.
Frequency Impedance SWR Mismatch Conductor Forward F/R
MHz ohms Loss dB Loss dB Gain dBd dB
88 130-j94 2.58 0.94 0.01 4.47 8.33
89 146-j62 2.17 0.63 0.01 4.81 10.38
90 162-j34 1.88 0.43 0.01 4.98 12.17
91 178-j10 1.69 0.30 0.01 5.04 13.38
92 192+j13 1.57 0.22 0.01 5.05 13.94
93 205+j34 1.50 0.18 0.01 5.04 13.90
94 218+j55 1.47 0.16 0.01 5.01 13.50
95 230+j75 1.47 0.16 0.01 4.98 12.93
96 242+j96 1.51 0.18 0.01 4.95 12.32
97 256+j115 1.55 0.21 0.01 4.92 11.71
98 270+j137 1.63 0.26 0.01 4.89 11.15
99 285+j159 1.72 0.31 0.01 4.86 10.64
100 301+j181 1.81 0.38 0.01 4.83 10.16
101 319+j205 1.92 0.45 0.01 4.79 9.72
102 340+j228 2.03 0.54 0.01 4.76 9.32
103 366+j251 2.15 0.62 0.01 4.72 8.94
104 394+j274 2.27 0.71 0.01 4.68 8.61
105 426+j295 2.39 0.80 0.01 4.65 8.30
106 464+j313 2.50 0.88 0.01 4.61 8.05
107 507+j326 2.59 0.95 0.01 4.58 7.84
108 554+j329 2.67 1.00 0.01 4.58 7.71
Stellar Labs 4-Element Yagi Free Space Symmetric 98 MHz 7 6063-T832 wires, mm ab = 46 ; DE distance above boom bb = 37 ; DE distance below boom dep = 629 ; element positions d1p = 1113 d2p = 1630 r = 808 ; element half-lengths de = 705 d1 = 589 d2 = 589 1 0 -r 0 0 r 0 10 1 dep -de -bb dep de -bb 10 1 dep -de ab dep de ab 10 1 dep -de ab dep -de -bb 10 1 dep de ab dep de -bb 10 1 d1p -d1 0 d1p d1 0 10 1 d2p -d2 0 d2p d2 0 10 1 source Wire 2, center
You can improve forward gain a small amount by extending the boom and adding an element. Use one 96″ length of 6063-T5 aluminum angle. Cut a 49¾″ piece for the element. Use the remainder, doubled up side by side, to support it 22″ in front of the last director. Use the same dimensions for ⅜″ or 10 mm tubing.
Joe Comer, AD3P, in Severna Park, Maryland, modified his antenna. The modification improved reception of a favorite but weak station at the low end of the band.
George S. Martins modified this antenna in Sobral, Ceará, Brazil. He has received 600 km aircraft scatter with it.
Zack Schlinder, N8FNR, uses this modified Yagi in Royal Oak, Michigan.
88–108 MHz