DG7YBN / 144 MHz - 70cm / YBN 3+7 SAT
  Last Update Feb. 09th, 2019




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Performance Data and Geometry
Pattern and VSWR


YBN 3+7 SAT  Compact Yagi for Satellite Operation, handheld or on small tripod



A compact Yagi for 145 MHz & 435 MHz satellite operation, to be used handheld or mounted on a small tripod. Design date of issue: 2019.02.09



70 cm and 2 m 3D patterns

 




Performance Data

Specs: with 1/4 inch = 6.35 mm elements @ 144.1 MHz

Gain vs. isotr. Rad.   7.1 dBi
Gain vs. Dipole        5.0 dBD
-3 dB E-plane         68.4 deg.
-3 dB H-plane        122.4 deg.
F/B                  -19.3 dB
F/R                   -8.4 dB
Impedance               50 ohms
VSWR Band Width       < 1:1.2 for 144.5 - 146 MHz
Mechan. Length         910 mm
Electr. Length        0.44 λ at 145.8 MHz


Specs: with 1/4 inch = 6.35 mm elements @ 435 MHz

Gain vs. isotr. Rad.  12.2 dBi
Gain vs. Dipole       10.1 dBD
-3 dB E-plane         43.8 deg.
-3 dB H-plane         51.4 deg.
F/B                  -26.5 dB
F/R                  -20.1 dB
Impedance               50 ohms
VSWR Band Width       < 1:1.2 for 430 - 440 MHz
Mechan. Length         900 mm
Electr. Length        1.31 λ at 435 MHz


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Geometry

Table 1: 2 m section, 6.35 mm elements through a 5/8 inch boom,
formast mount with 280 mm offset on rear boom end:




"Ready to saw and drill" data for mounting elements through boom with BC according SM5BSZ's BC.exe:

This table is only valid for:
Boom shape: square
Boom dim: 5/8 x 5/8 inch
Wall thickn.: 1/6 inch = 1.6 mm
Holes in boom: 8.0 mm
Offset rear: 280 mm
Offset front: 30 mm
 


Note: This does include an SBC of 0 mm








Table 2: 70 cm section, 6.35 mm elements through a 5/8 inch boom,
formast mount with 280 mm offset on rear boom end:




"Ready to saw and drill" data for mounting elements through boom with BC according SM5BSZ's BC.exe:

This table is only valid for:
Boom shape: square
Boom dim: 5/8 x 5/8 inch
Wall thickn.: 1/6 inch = 1.6 mm
Holes in boom: 8.0 mm
Offset rear: 280 mm
Offset front: 30 mm
 


Note: This does include an SBC of 1.74 mm plus a correction for the insulators (v-factor!) of 0.7 mm = 2.44 mm






Sketch of Bent Dipole for 70 cm









Pattern and VSWR Plots

Current distribution Elevation and Azimuth plot at 145.8 MHz

 


VSWR plots - simulated 2 m


Return Loss plot - simulated 2 m





Elevation and Azimuth plot at 435.0 MHz

 


VSWR plots - simulated 70 cm


Return Loss plot - simulated 2 m










73, Hartmut, DG7YBN



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