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 YBN 705m
A 0.5 m 432 MHz blue print of the YBN 25m 50 ohms
high F/B direct feed 144 MHz Low Noise Yagi 3D Plot
 YBN 7014wz
Tune up your 19 ele. Tonna!A design based on the hardware of the F9FT,
turning it into a 14 ele. OWL with cleaner pattern, +0.3 dB gain and SWR less than 1.2 from 430 to 440 MHz Azimuth Plot
 GTV 702w
A 0.14 m GTV useful for portable operation and up to the satellit band
and handheld activities of any kind Elevation Plot
 GTV 703w
A 0.21 m GTV useful for portable operation and up to the satellit band
and lower noise stacks of any kind Elevation Plot
 GTV 704m
A 0.34 m GTV useful for portable operation up to the satellit band
and lower noise stacks of any kind Elevation Plot
 GTV 707n
A 1.1 m 432 MHz blue print of the low impedance, yet 50 ohms
direct feed 144 MHz Low Noise Yagi introduced in Dubus 1/2013 Elevation Plot
 GTV 708n
A 1.3 m 432 MHz GTV with high gain but low backlobe volume. Makes
a very compact 4 Yagi bay for QRP EME or contesting.
Elevation Plot
 GTV 709w
A 1.44 m GTV ment to be useful as a vertical stack for contesting
or be an ideal small size portable Yagi Elevation Plot
 GTV 7011w
A 2.01 m GTV ment to be useful as a vertical stack for contesting
or be an ideal small size portable Yagi or minimum size EME 4 bay Elevation Plot
 GTV 7014m
2.9 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7017m
3.7 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7019m
4.2 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7023m
5.3 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7025m
5.9 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7030m
7.3 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7034w
8.5 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot
 GTV 7046w
12.0 m version of the low impedance, yet 50 ohms
direct feed Low Noise Yagi with bent DE introduced in Dubus 1/2013 Elevation Plot

....... 
Performance Data and Geometry
Pattern and VSWR
Download as File
Stacking
Stagger Stacked 4 Bay
Matching
GTV 709w Yagi with bent Driven Element
EME + SSB band to FM up to 436 MHz. With marginal degradation it can be used even in the
satellite band section (max. VSWR 440 MHz ~ 1.5). Its VSWR is flat well below 1.1 from 430 to 436 MHz.
This Yagi has very low back lobes for its length. It may serve as single antenna for portable
use and certainly make a useful 4 x vertical stack. It makes a quiet contest antenna due to its
high F/B. The bent DE (K6STI style) transforms from approx. 17 ohms to 50 ohms at feed point.
4 x vertical 'stagger stack' of GTV 709w built by Mathias, DJ5QX: Click on images to enlarge
Look up the effect of stagger stacking for this bay simulated with CST Software
GTV 709w built by Mathias, DJ5QX
and his plots with HP8753C, precalibrated with HPCalkit, thru 10 m of EcoFlex 10, final 200 mm of RG316
dismissed by applying port extension: Return Loss, S11 and Z = R + jX as Smith Chart.
We find 2 chartlines for antenna beaming at different angles for judging the influence of the home 'test range'.
And Sheet Metal Dipole the other way round:
GTV 709w built by Kazuo, 7L1TIG, see his website for details and VSWR plot
Photo: with kind permission of Kazuo, 7L1TIG
Current distribution
3D Pattern
Performance Data
Specs: with 4 mm elements @ 432.1 MHz
Gain vs. isotr. Rad. 13.5 dBi
Gain vs. Dipole 11.4 dBD
3 dB Eplane 40.4 deg.
3 dB Hplane 45.8 deg.
F/B 30.0 dB
F/R 25.5 dB
Impedance 50 ohms
Mechan. Length 1438 mm incl. 2 x 30 mm stand off
Electr. Length 1.99 λ
Stacking dist. hpol.
toptobottom 0.89 m or 2.92 ft
sidebyside 1.00 m or 3.29 ft
How many OMs have been looking up this design?
Geometry
Ø8 mm Elements  On Boom  Dimensions (BC acc. DG7YBN)
Actual BC for on a 20 x 20 mm Boom with standard insulators is 7.5 mm, SBC is 1.46 mm,
total length to add is 8.96 mm ~ 9.0 mm
Refl DE(b) DE(a) D1 D2 D3 D4 D5 D6 D7
Pos. 0 82.7 104.5 151 247 428 641 884 1145 1378
NEC 1/2 ele. 164.5 (161.7) (33.5) 154.5 151.0 145.0 141.5 137.0 133.0 126.5
Boom 20x20 mm 338.0 (332.4) (67.0) 318.0 311.0 299.0 292.0 283.0 275.0 262.0
Bent Dipole: DE(a) is the inner straight length and pos. on boom, DE(b) is position of tips and span width when bent
<= NEC Geometry for 4 mm ele. insulated through boom excluding BC
Ø4 mm Elements  Through Boom  Dimensions (BC acc. SM5BSZ's BC.exe)
EZNEC wire table for Ø 4 mm elements
The model uses EZNEC's AutoSegmentation at 1050 MHz.
The DE's is 10 mm for all examples.
Using a 'Blade Dipole' is recommended with elements through boom
A simple symmetrising section may be made from a 3 x 1/4 Lambda line grounded at the far end with
Nflangebushing and an aluminium plate and ferrite core added as close as possible to the DE,
see below.
Table 1: GTV 709w, 4 mm elements through boom:
"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: 20 x 20 mm
Wall thickn.: 2.0 mm
Holes in boom: 6.0 mm
Offset rear: 30 mm
Offset front: 30 mm
Note:
This does include a "Segmentation Density Correction" (SBC) of 1.46 mm.
Which does not include any correction for the insulators, which is around 0.7 mm depending on
the very insulator properties and is still to be added to the length of each element as fix offset.
Read abt. the SBC here .
Table 2: GTV 709w, 4 mm elements through boom,
formast mount with 380 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: 20 x 20 mm
Wall thickn.: 2.0 mm
Holes in boom: 6.0 mm
Offset rear: 380 mm
Offset front: 30 mm
Note:
This does include an SBC of 1.46 mm plus a correction for the insulators (vfactor!) of 0.7 mm
The CVS file for the Yagi Element Configuration Tool for own variations:
You can find the CSV file containing the set of data for this design in the download section.
Import that into my Yagi Element Configuration Tool and do your own adaption.
Building hints:
For building hints see the GTV 7019
For fastening elements through boom
For making of a 'Blade Dipole' which I recommend for elements through boom builds
Radiation Pattern and VSWR Plots
Elevation and Azimuth plot at 432.1 MHz
SWR and Return Loss plots  simulated with 4nec2
Gain, F/B and F/R 431 to 434 MHz
Radiation Pattern 430 to 440 MHz, Elevation Pattern
Downloads
EZNEC file of this Yagi with Ø 4 mm ele.
EZNEC file of this Yagi with Ø 8 mm ele.
CSV file for the Yagi Element Configuration Tool with 4 mm elements
Stacking
As on 432 MHz the Yfactor = 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 Hplane.
Stacking Dist. DL6WU Formula
Hplane 1.00 m
Eplane 0.89 m
A vertical 4 Yagi stack
Elevation plot and data of 4 Yagi bay using DL6WU stacking distances
Gain vs. isotr. Rad. 19.36 dBi
Gain vs. Dipole 17.21 dBD
3 dB Hplane, appr. 40.8 deg.
3 dB Eplane, appr. 10.0 deg.
F/B 29.4 dB
F/R 28.8 dB
T_ant 30.3 K*
G/T 4.54 dB*
Theoretical numbers  these do not include phasing line losses
nor imperfections caused by Hframes or mast poles etc.
*) T_sky = 20 K, T_earth = 350 K as in VE7BQH G/T table
Screenshot of TANT for this 4 Yagi stack
A vertical 6 Yagi stack
21.1 dBi at a HPBW of 40 degr. on less than 4.5 m of height on pole
Stagger Stacked 4 x GTV 709w
Stacking distance is acc. DL6WU = 890 mm + 70 mm = 960 mm each
Gain vs. isotr. Rad. 19.51 dBi
Gain vs. Dipole 17.36 dBD
F/B 47.4 dB
F/R 32.1 dB
Inner Yagis are displaced in forward direction by 169 mm and fed at 90 degr
Free Space Elevation Pattern
Simulated at 3.0 m over perfect ground  4nec2's 3D viewer  structure and pattern
Simulated at 3.0 m over perfect ground  Azimuth Pattern
View the effect of Stagger Stacking on a 4 x vert. bay of 4 GTV 709w simulated with CST EM Software (tnx Mathias, DJ5QX!)
• Conventional Stack at DL6WU distances.
These are nonnormalised cartesian plots: At 20 dB of forward gain a 10 dB (mark 1, 2) on rear lobe means 30 dB of F/B.
• Stagger stacked as described above
Read more about Stagger stacking here
and here
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 vfactors specified in a catalogue only.
A good choice may be the diam. 5 mm PTFE coax RG142 B/U: real resonate length (432.2 MHz as 3/4 Lambda) shieldshield is around 348 mm
Find more information on Phasing & Matching Lines page
73, Hartmut, DG7YBN

