Gain vs. isotr. Rad.   6.4 dBi
Gain vs. Dipole        4.2 dBD
-3 dB E-plane         71.2 deg.
-3 dB H-plane        134.0 deg.
F/B                  -10.1 dB
F/R                   -6.4 dB
Impedance               50 ohms
VSWR Band Width       1.06:1 *
Mechan. Length        410 mm plus boom ends offset
Electr. Length        0.19 λ

Stacking Dist. h-pol.
top-to-bottom         1.2 m or 3.9 ft **
side-by-side          xx m or xx ft

*) as in VE7BQH G/T table = at 145.00 MHz
**) needs adapted geometry

Gain vs. isotr. Rad.  10.1 dBi
Gain vs. Dipole        8.0 dBD
-3 dB E-plane         72.4 deg.
-3 dB H-plane         49.0 deg.
F/B                  -21.5 dB
F/R                  -16.8 dB
Impedance               50 ohms
VSWR Band Width       1.17:1 *
Mechan. Length        410 mm plus boom ends offset
Electr. Length        0.19 λ

Stacking Dist. h-pol.
top-to-bottom         1.2 m or 3.9 ft **
side-by-side          xx m or xx ft

*) as in VE7BQH G/T table = at 145.00 MHz

Gain vs. isotr. Rad.  10.2 dBi
Gain vs. Dipole        8.0 dBD
-3 dB E-plane         46.2 deg.
-3 dB H-plane         48.8 deg.
F/B                  -21.1 dB
F/R                  -17.6 dB
Impedance               50 ohms
VSWR Band Width       1.33:1 *
Mechan. Length        2 x 351 mm plus boom end offsets
Electr. Length        0.17 λ

Stacking Dist. h-pol.
top-to-bottom         1.2 m or 3.9 ft **
side-by-side          xx m or xx ft

*) as in VE7BQH G/T table = at 145.00 MHz

 : 

Return Loss (s11) and SWR plots - simulated with 4nec2:

How many VHF operators have been looking up this design since Oct 2021?

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Geometry

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

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This Yagi with 8 mm elements on a 15 x 15 mm boom with standard insulators

Ele. 8.0 mm DE 10 mm Boom 15 x 15 mm

"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for standard insulators as sold by Konni, Nuxcom, WiMo, 7arrays:


Includes an SBC of 2.93 mm

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This Yagi with 8 mm elements on a 20 x 20 mm boom with standard insulators

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 Konni, Nuxcom, WiMo, 7arrays:


Includes an SBC of 2.93 mm

SegmentationBC = +2.93 mm = (144.7 MHz - 144.2 MHz) * 5.85 mm/MHz
BaseBC (20x20) = +3.90 mm for semi-insulated on boom
Total          = +6.83 mm				
Note: element lengths for Ø 8 mm fit 5/16" too

SegmentationBC = +2.93 mm = (144.7 MHz - 144.2 MHz) * 5.85 mm/MHz
BaseBC (20x20) = +3.90 mm for semi-insulated on boom
Add for Ins.   = +1.46 mm
Total          = +8.29 mm				
Note: element lengths for Ø 8 mm fit 5/16" too

The Drivers diameter is 10 mm for all examples.
The EZNEC model is done with Auto-Segmentation at 400 MHz

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This Yagi with 3/8 inch elements on a 1 x 1 inch boom with hydraulic clamps (like Stauff) or SM7DTT insulators

Ele. 3/8 inch or 9.53 mm DE 3/8 inch Boom 1 x 1 inch

"Ready to saw and drill" data for mounting elements on boom with BC according DG7YBN for hydraulic clamps (like Stauff) or SM7DTT insulator:


Includes an SBC of 2.93 mm

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Table 2: GTV 2-6m, 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

This table is only valid for: 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!



Table 3: GTV 2-6m, 4.76 mm elements through boom:

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Imperial Boom 1 x 1 inch x 1.6 mm

This table is only valid for: Boom shape: square Boom dim: 25.4 x 25.4 mm Wall thickn.: 1.6 mm Holes in boom: 7.5 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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Sketch of Bent Dipole

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Pattern and VSWR Plots

Elevation and Azimuth plot at 144.1 MHz

 

RL and SWR plots - simulated

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Downloads

EZNEC file of this Yagi with 8 mm elements  

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xpol Details

Pattern with both sources = dipoles fed

General Hints for tuning xpol Yagis

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(1) Set up the h-plane only
(2) Tune and plot Return Loss

See to make this single plane work fine, only then proceed.

(4) Add v-plane
(5) Replot h-plane
(6) If h-plane is still fine
(7) Mount the Yagi turned by 90 degr. so that freshly added v-plane is in h
(8) Tune and plot v-plane (in h now)

By measuring and trimming the v-plane in position horizontal we eliminate
possible unknown influences v to h mount for the while being. We would not
like to handle two unkowns at a time.

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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!


Table 2: GTV 2-6m xpol, 4 mm elements through boom:

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Metric Boom 20 x 20 x 2 mm

This table is only valid for: Boom shape: square Boom dim: 20 x 20 mm Wall thickn.: 2.0 mm Holes in boom: 6.0 mm Offset rear: 750 / 860 mm Offset front: 150 / 40 mm

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

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Table 3: GTV 2-6m xpol, 4.76 mm elements through boom:

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Imperial Boom 1 x 1 x 1/16 inch

This table is only valid for: Boom shape: square Boom dim: 1 x 1 inch Wall thickn.: 1.6 mm Holes in boom: 7.5 mm Offset rear: 750 / 860 mm Offset front: 150 / 40 mm

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




Table 4: GTV 2-6m xpol, 3/8 inch or 9.53 mm elements on boom with hydraulic clamps (like Stauff) or SM7DTT insulators :

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Imperial Boom 1 x 1 inch

Ele. 3/8 inch or 9.53 mm DE 3/8 inch Boom dim: 1 x 1 inch Offset rear: 750 / 860 mm Offset front: 150 / 40 mm

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

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Stacking

Stacking Dist.    DL6WU Formula
E-plane               2.65 m or 8.7 ft
H-plane               2.19 m or 7.2 ft

Plot and data of 2 vertically stacked GTV 2-6m using DL6WU stacking distances

Antenna View & Elevation Pattern

Plot and data of 4 vertically stacked GTV 2-6m using DL6WU stacking distances

Antenna View, Elevation & Azimuth Pattern

Plot and data of 4 bay of GTV 2-6m using DL6WU stacking distances

Elevation & Azimuth Pattern

AGTC_lite screenshot (Traditional Temps: Tsky = 200 K, Tearth = 1000 K)

AGTC_lite screenshot (Redefined Temps: Tsky = 287 K, Tearth = 5126 K acc. ITU)

Gain vs. isotr. Rad.  17.9 dBi
Gain vs. Dipole       15.7 dBD
-3 dB H-plane         25.2 deg.
-3 dB E-plane         20.6 deg.
F/B                  -33.0 dB
F/R                  -23.4 dB
T_los                  3.5 K
T_ant                498.6 K*  (236.1 K)
G/T                  -9.10 dB* (-5.85 K)

Theoretical numbers, no phasing line losses
nor imperfections caused by H-frame included
*) T_sky = 287 K, T_earth = 5126 K as in VE7BQH G/T table


16 x GTV 2-6m xpol ... 23.4 dBi: click to enlarge

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146.5 MHz DATV Version of the GTV 2-6m

This is a scaled to 146.5 MHz version of the GTV 2-6m.

Element lengths and positions are adapted to 146.5 MHz.

Hence the Pattern is same as for the 144 MHz Version

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This Yagi with 8 mm elements on a 20 x 20 mm boom with standard insulators

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 Konni, Nuxcom, WiMo, 7arrays:


Includes an SBC of 3.04 mm

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This Yagi with 8 mm elements through a 25 x 25 x 1.5 mm boom

Ele. 8.0 mm DE 10.0 mm Boom 25 x 25 x 1.5 mm

"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!

This table is only valid for:
Boom shape: square
Boom dim: 25 x 25 mm
Wall thickn.: 1.5 mm
Holes in boom: 10.0 mm
Offset rear: 40 mm
Offset front: 40 mm

Includes an SBC of 3.04 mm

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Stacking Info 146.5 MHz DATV Version

Stacking Dist. h-pol.
top-to-bottom     2.16 m or 7.1 ft
side-by-side      2.61 m or 8.55 ft

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73, Hartmut, DG7YBN