DG7YBN / 144 MHz / YBN 2-12wz
  Last Update June 20th 2013




.......



Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking
Matching


YBN 2-12wz wideband 12.5 ohms Yagi   with straight dipole

144.0 to 145.6 MHz Wideband Antenna Version (OWA style)

This Yagi has very low back lobes for its length. It may serve as a single powerful antenna for Tropo and EME
or make a quiet contest antenna due to its high F/B. The straight DE may be matched to 50 ohms at feed point with an
improved DK7ZB style 2 x 50 ohms quarter wave line (see end of page).

Parameters are quite similar to the performance the GTV2-12mk2 offers. This Yagi thus may demonstrate that the bent DE
but transformates from low impedance to 50 ohms as an integrated member of the antennas structure.

Current distribution




Performance Data

Gain vs. isotr. Rad.  15.5 dBi
Gain vs. Dipole       13.4 dBD
-3 dB H-plane         31.8 deg.
-3 dB E-plane         34.2 deg.
F/B                  -30.7 dB
F/R                  -28.1 dB
Impedance             12.5 ohms
Mechan. Length        6770 mm
Electr. Length        3.25 λ

Stacking Dist. h-pol.    DL6WU     max. G/T
top-to-bottom           3.54 m      x.xx m
side-by-side            3.80 m      x.xx m
Geometry


        Pos.    Full Length    Full Length     incl. BC
                Free Space     Free Space   on 25x25 Boom

Refl.     0      1031.0         1026.0         1035.9
DE      208       976.0          976.0          985.9
D1      402       979.0          966.0          975.9
D2      694       958.0          942.0          951.9
D3     1236       945.0          928.0          937.9
D4     1886       929.0          910.0          919.9 
D5     2628       919.0          898.0          907.9
D6     3414       908.0          884.0          893.9
D7     4276       899.0          877.0          886.9
D8     5140       891.0          866.0          875.9
D9     5997       887.0          862.0          871.9
D10    6770       869.0          842.0          851.9
 
                ele. 4 mm      ele. 8 mm      ele. 8 mm

4 mm elements insulated through boom BC:
Use DJ9BV BC numbers and nylon rivets on square boom as shown on BC-page
PLUS added Segmentation BC of +2.3 mm as below
				
On Boom BC:				
SegmentationBC = +2.3 mm = (144.6 MHz - 144.2 MHz) * 5.85 mm/MHz
BaseBC (25x25) = +7.6 mm for semi-insulated on boom
Total          = +9.9 mm				
Note: element lengths for Ø 8 mm fit 5/16" too

The Drivers diameter is 10 mm for all examples.
Use EZNEC's Auto-Segmentation at 380 MHz.







Pattern and VSWR Plots

Elevation and Azimuth plot at 144.1 MHz

 


SWR and Return Loss plots - simulated with 4nec2










Downloads

EZNEC file of this Yagi  

EZNEC file of this Yagi as 4 bay using DL6WU distances  









Stacking

   



Stacking Dist.    DL6WU Formula    max. G/T
H-plane               4.21 m        4.45 m
E-plane               4.39 m        4.60 m

Elevation and azimuth plot and data of 4 Yagi bay using DL6WU stacking distances

   


Gain vs. isotr. Rad.  21.47 dBi
Gain vs. Dipole       19.32 dBD
-3 dB H-plane         14.4 deg.
-3 dB E-plane         15.4 deg.
F/B                  -32.6 dB
F/R                  -32.6 dB
T_ant                223.6 K*
G/T                  -2.02 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by H-frame included
*) T_sky = 200 K, T_earth = 1000 K as in VE7BQH G/T table










Matching 12.5 to 50 ohms

Coax line transformer principle and applied concept = the ferrite improved DK7ZB - Match

   

  Attenzione!     Take care when lengthening the cables, measure the right length instead of refering to given v-factors only.
                                      A good choice may be the diam. 5 mm PTFE coax RG-142 B/U: real resonate length (144.1 Mhz) shield-shield is around 345 mm


  Find more information on Phasing & Matching Lines page






73, Hartmut, DG7YBN


Flag Counter