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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
Matching
GTV 7017m Yagi with bent Driven Element
EME + SSB to mid of band Longyagi
This Yagi has very low back lobes for its length. It may serve as single antenna for Tropo or make quiet 4 Yagi EME array.
It also makes a quiet contest antenna due to its very high F/B and clean rear pattern. The bent DE (K6STI style) transforms from approx. 17 ohms to 50 ohms at feed point.
Read about it in Practical Wireless, issue Febr. 2018
20171202: M6 license holder M6EBQ does EME with 10 W out into a single GTV 7017 element Yagi
Another one for the history book: This seems the very first moon bounce contact by an M6 license holder
using but his (her) ten watt and a single Yagi.
M6 Licenses are restricted to 10 W out. We have seen an M6 EME contact before using a 4 bay of LFA Hybrid Yagis by Boban, YU7XL.
However this time a sole GTV 7017n did the job. On the other side DL7APV, meanwhile equipped with 16 x 9 wl DJ9BV for hpol
and 8 x GTV 7011w for vpol could even give a 22 dB report via WSJT giving "tnx QSO 22".
Congratulations to Dorothy, M6EBQ and Bernd, DL7APV ... and also Thomas, M0ABA for building the fine Yagi
And this QSO received at DG7YBN on single GTV 7019m
Another first built by Thomas, M0ABA: GTV 7017m ready for the ARRL EME Contest
Final Blade Dipole shape (on left) and adjustable experimenters blade to find the shape needed (on right), far right: simple elevation mount by M0ABA
Boom is 1 x 1 inch, elements 4.0 mm, insulators by 7arrays.
How Thomas, M0ABA feeds these Yagis: self engineered coax hardline stub, the base plates are sawn from kitchen plastic boards(!)
A smart idea to access plastic sheets in the right thickness in small quantites at a reasonable price.
Feasible Return Loss: > 50 dB at 432.8 MHz
And this how the Yagi performs:
WSJT Screenshot QSO NC1I <> MX0CNS with GTV 7017m and 60 W at Feed
2017.11.03: DL7APV <> EME with single GTVV7017m and just 10 W at feed
2017.11.04: 8 Yagi station ON4GG received with single GTVV7017m during ARRL EME Contests 2nd leg
2017.11.04: 4 x 21 ele. Tonna station FR5DN received with single GTVV7017m during ARRL EME Contests 2nd leg
Current distribution
Performance Data
Specs: with 8 mm elements @ 432.1 MHz
Gain vs. isotr. Rad. 17.3 dBi
Gain vs. Dipole 15.1 dBD
3 dB Eplane 26.6 deg.
3 dB Hplane 27.8 deg.
F/B 38.3 dB
F/R 31.5 dB
Impedance 50 ohms
Mechan. Length 3628 mm
Electr. Length 5.23 λ
Stacking Dist. hpol.
toptobottom 1.51 m or 4.95 ft
sidebyside 1.44 m or 4.74 ft
Geometry
The Drivers diameter is 10 mm for all examples.
Use EZNEC's AutoSegmentation at 1050 MHz.
A simple symmetrising member may be made from a 3 x 1/4 Lambda line grounded at the far side with
Nflangebushing and an aluminium plate and ferrite added as close as possible to the DE, see below.
How many OMs have been looking up this design?
Geometry for 8 mm elements
Using a large calliper gauge to control lenghts to the 10th of a millimeter is a must.
Geometry for 4 mm elements
"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: 1 x 1 inch
Wall thickn.: 1/8 inch (3.175 mm)
Holes in boom: 6.0 mm
Offset rear: 40 mm
Offset front: 40 mm
Note:
This includes a "Segmentation Density Correction" (SBC) of 0.90 mm plus an offset of 0.70 mm per element = 1.60 mm.
for compensation of the insulators shown with the GTV 7019m website. Note: Other insulators will need slightly other offset,
with their length being probably the most important parameter for this. Thus I advise to cut other plastic insulators
to 7 mm each to match at least the length of the pilot insulators.
Read abt. the SBC here .
Using a large calliper gauge to control lenghts to the 10th of a millimeter is a must.
Pattern and VSWR Plots
Elevation and Azimuth plot at 432.1 MHz
SWR and Return Loss plots  simulated with 4nec2
Downloads
EZNEC file of this Yagi with 4 mm elements
EZNEC file of this Yagi with 8 mm elements
Stacking
As on the 432 MHz Band the Yfactor = T_earth / T_sky is that high I see little chances in
bettering an array's RX performance by using "Over Stacking" distances. However, depending
the level of local QRM it might be worthwhile to try less distance, especially in Hplane.
Stacking Dist. DL6WU Formula
Hplane 1.44 m
Eplane 1.51 m
Elevation and azimuth plot and data of 4 Yagi bay using DL6WU stacking distances
AGTC_lite screenshot of this Yagi with 8 mm elements
Gain vs. isotr. Rad. 23.20 dBi
Gain vs. Dipole 21.05 dBD
F/B 33.6 dB
F/R 32.8 dB
T_ant 28.5 K*
G/T 8.65 dB*
Theoretical numbers, no phasing line losses
nor imperfections caused by Hframe included
*) T_sky = 20 K, T_earth = 350 K as in VE7BQH G/T table
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 right length instead of refering to given vfactors 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

