Gain vs. isotr. Rad.  17.6 dBi
Gain vs. Dipole       15.4 dBD
-3 dB E-plane         25.8 deg.
-3 dB H-plane         26.8 deg.
F/B                  -33.5 dB
F/R                  -30.1 dB
Impedance               50 ohms
Mechan. Length        3969 mm incl. 2 x 40 mm stand off
Electr. Length        5.61 λ

VSWR Bandwidth        1:1.08 (as in VE7BQH Antenna Table)

Stacking dist. h-pol.
top-to-bottom         1.51 m or 4.95 ft
side-by-side          1.57 m or 5.14 ft

How many OMs have been looking up this design?



Geometry

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Ø8 mm Elements - On Boom - Dimensions (BC acc. DG7YBN)

Ele. 8.0 mm DE 10 mm Boom 20 x 20 mm

"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for standard insulators as sold by WiMo, Tino's Funkshop, 7arrays, HF-Kits.nl:

Includes an SBC of 1.14 mm

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Ø8 mm Elements - On Boom - Dimensions (BC acc. DG7YBN)

Ele. 8.0 mm DE 10 mm Boom 25 x 25 mm

"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for standard insulators as sold by WiMo, Tino's Funkshop, 7arrays, HF-Kits.nl:

Includes an SBC of 1.14 mm

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Table 2: GTV 70-21n, 4 mm elements through boom:

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"Ready to saw and drill" data for mounting elements through boom with BC according SM5BSZ's BC.exe:
Note: with through Boom BC it is important to stick to the boom end offsets given below!

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Metric Boom 20 x 20 x 2 mm

Boom shape: square Boom dim: 20 x 20 mm Wall thickn.: 2.0 mm Holes in boom: 6.0 mm Offset rear: 40 mm Offset front: 40 mm

Note: with through Boom BC it is important to stick to the boom end offsets given below!

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Metric Boom 25 x 25 x 2 mm

Boom shape: square Boom dim: 25 x 25 mm Wall thickn.: 2.0 mm Holes in boom: 6.0 mm Offset rear: 40 mm Offset front: 40 mm

Note: with through Boom BC it is important to stick to the boom end offsets given below!

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Imperial Boom 1" - El. 4.00 mm

Boom shape: square Boom dim: 1 x 1 inch Wall thickn.: 1.6 mm Holes in boom: 6.0 mm Offset rear: 40 mm Offset front: 40 mm

Note: All the above include a "Segmentation Density Correction" (SBC) of 1.14 mm plus an offset of 0.70 mm per element = 1.84 mm
for compensation of the insulators (7arrays.com ) as shown above in combination with SM5BSZ'S BC.exe values.

Note: with through Boom BC it is important to stick to the boom end offsets given below!

Read abt. the SBC here .

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Imperial Boom 1" - El. 4.763 mm or 3/16 inch

Boom shape: square Boom dim: 1 x 1 inch Wall thickn.: 1.4 mm Holes in boom: 7.7 mm Offset rear: 40 mm Offset front: 40 mm

Note: All the above include a "Segmentation Density Correction" (SBC) of 1.14 mm plus an offset of 0.70 mm per element = 1.84 mm
for compensation of the insulators in combination with SM5BSZ'S BC.exe values.

Note: with through Boom BC it is important to stick to the boom end offsets given below!

Read abt. the SBC here .

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For making of a 'Blade Dipole' which I recommend for elements through boom builds

Sketch of Bent Dipole

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Radiation Pattern and VSWR Plots

Elevation and Azimuth plot at 432.1 MHz (8 mm ele.)

 

Elevation and Azimuth plot at 435 MHz (8 mm ele.)

 

Elevation and Azimuth plot at 439 MHz (8 mm ele.)

 

VSWR and Return Loss plots - simulated with 4nec2

Wide Return Loss plot of 4 mm version - simulated with 4nec2

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This Yagi as XPOL 435 MHz Version



EZ/AZ Plot (4 mm ele.):



h/v-plane offset = 680 mm,
Stacking per DL6WU h/v mean dist. = 1.54 m

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This Yagi with 4 mm elements through a 25 x 25 mm boom Metric Boom 25 x 25 x 2 mm

Boom shape: square Boom dim: 25 x 25 mm Wall thickn.: 2.0 mm Holes in boom: 6.0 mm Offset rear: 40 mm h-plane,720 mm v-plane Offset front: 720 mm h-plane, 40 mm v-plane

Note: with through Boom BC it is important to stick to the boom end offsets given below!

Includes an SBC of 1.84 mm

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Stacking

As on 432 MHz the Y-factor = T_earth / T_sky is so high, I see little chances to
improve an array's RX performance by using "Over Stacking" distances. However, depending on
the level of local QRM it might be worthwhile to try a decreased distance, especially in the H-plane.

Stacking Dist.    DL6WU Formula
H-plane               1.51 m or 4.95 ft
E-plane               1.57 m or 5.14 ft

A 4 Yagi bay

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Elev. Plot

Azim. Plot

4 bay data (8 mm ele.):

Gain vs. isotr. Rad.  23.5 dBi
Gain vs. Dipole       21.3 dBD
-3 dB H-plane, appr.   5.8 deg.
-3 dB E-plane, appr.   5.8 deg.
F/B                  -34.0 dB
F/R                  -30.1 dB
T_ant, total          61.8 K*
G/T                   5.56 dB*

at Tsky = 27 K, Tearth = 1800 K as in newer VE7BQH Antenna Table

3D pattern plot with 4nec2's 3D viewer

Antenna G/T with AGTC lite VBA-version:

at Tsky = 27 K, Tearth = 1800 K as in newer VE7BQH Antenna Table

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Symmetrising 50 to 50 ohms feedline to 432 MHz Bent DE

The principle is similar to the 1/4 Lambda coax. Adding 2 x 1/4 Lambda or a half wave line does not change anything but allows
to form a gentle bow below the boom or until behind the Reflector. Follow practical construction hints on "Building a Yagi" page.

    

  Attenzione!     Take care when lengthening the coax, measure the actual electrical length instead of considering v-factors specified in a catalogue only.
                                      A good choice may be the diam. 5 mm PTFE coax RG-142 B/U: real resonate length (432.2 MHz as 3/4 Lambda) shield-shield is around 348 mm


  Find more information on Phasing & Matching Lines page






73, Hartmut, DG7YBN