yagi uda meshcore polska 869,620mhz

obecnie w testach użyto aluminiowej rurki 8mm, a jako dipola i direktorów przewodu miedzianego o średnicy 2mm (przewód zasilający) Obliczenia zrobione na kalkulatorze, baloon będzie zrobiony ze 114mm przewodu. dla dipola nie prostego balon w kształcie litery U dla najpopularniejszego przewodu koło 114mm przewodu w izolacji z ekranem. i jedną stronę tego przewodu lutujemy do gorącej żyły i do jednego wyjścia naszego dipolu, a drugą końcówkę do drugiego końca dipolu. wszystkie masy łączymy ze sobą

z balonem SWR mocno poza zakresem, po podłączeniu masy do bomu jest bardzo dobrze SWR.

to ważne żeby boom podłączyć do masy, nikt tego nie podaje, a jak mierzyłem fabryczne anteny yagi to bom był zawsze wpięty do masy (ekranu)

do prostego balon to 1/4 długości fali * współczynnik skrócenia. dla Tri-Lan 240 jest to 0,253450,81 = 69,9mm

VK5DJ's YAGI CALCULATOR

Yagi design frequency =869.62 MHz
Wavelength =345 mm
Parasitic elements fastened to a non-metallic or separated from boom
Folded dipole fully insulated from boom
Director/reflector diam =2 mm
Radiator diam =2 mm

REFLECTOR
167.9 mm long at boom position = 30 mm (IT = 80.0 mm)

RADIATOR
Single dipole 162.0 mm tip to tip, spaced 68.9 mm from reflector at boom posn 98.9 mm (IT = 77.0 mm)
Folded dipole 165.2 mm tip to tip, spaced 68.9 mm from reflector at boom posn 98.9 mm (IT = 78.5 mm)

DIRECTORS
Dir Length Spaced Boom position IT Gain Gain
(no.) (mm) (mm) (mm) (mm) (dBd) (dBi)
1 150.2 25.9 124.8 71.0 4.8 6.9
2 148.6 62.1 186.9 70.5 6.5 8.6
3 147.0 74.1 261.0 69.5 7.8 9.9
4 145.6 86.2 347.2 69.0 8.9 11.0
5 144.2 96.5 443.7 68.0 9.8 11.9
6 143.0 103.4 547.1 67.5 10.5 12.7
7 141.9 108.6 655.7 67.0 11.2 13.3
8 140.8 113.8 769.5 66.5 11.7 13.9

COMMENTS
The abbreviation "IT" means "Insert To", it is the construction distance from the element tip to the edge of the boom for through boom mounting

Spacings measured centre to centre from previous element
Tolerance for element lengths is +/- 1 mm

Boom position is the mounting point for each element as measured from the rear of the boom and includes the 30 mm overhang.The total boom length is 799 mm including two ends of 30 mm and 30 mm

The ACTIVE boom length is 739 mm is the length used in gain calculations (see manual)

The beam's estimated 3dB beamwidth is 41 deg

FOLDED DIPOLE CONSTRUCTION
Measurements are taken from the inside of bends
Folded dipole length measured tip to tip = 165mm
Total rod length =360mm
Centre of rod=180mm
Distance BC=CD=65mm
Distance HI=GF=60mm
Distance HA=GE=88mm
Distance HB=GD=115mm
Distance HC=GC=180mm
Gap at HG=10mm
Bend diameter BI=DF=35mm

If the folded dipole is considered as a flat plane (see ARRL Antenna Handbook) then its resonant frequency is less than the flat plane algorithm's range of 10:1

MATERIALS GUIDE for purchase. Allow extra, do NOT use these figures for cutting
NO allowance for saw cuts or purchased lengths resulting in waste

1. Length used by directors and reflector 1329.2mm of round 2mm rod
2. Length used by single dipole 162.0mm or folded dipole 360.4 mm of round 2mm rod
3. Length used for boom 799.5 mm allowing for overhangs of 30 mm and 30 mm of 8 mm diameter round stock