Yagi design frequency =859,00 MHz Wavelength =349 mm Parasitic elements fastened to a non-metallic or separated from boom Folded dipole fully insulated from boom Director/reflector diam =4 mm Radiator diam =8 mm REFLECTOR 169,1 mm long at boom position = 30 mm (IT = 72,0 mm) RADIATOR Single dipole 159,2 mm tip to tip, spaced 70 mm from reflector at boom posn 100 mm (IT = 67,0 mm) Folded dipole 162,4 mm tip to tip, spaced 70 mm from reflector at boom posn 100 mm (IT = 68,5 mm) DIRECTORS Dir Length Spaced Boom position IT Gain Gain (no.) (mm) (mm) (mm) (mm) (dBd) (dBi) 1 147,2 26,2 126,0 61,0 4,8 6,9 2 145,3 62,8 188,8 60,0 6,5 8,6 3 143,5 75,0 263,8 59,5 7,8 9,9 4 141,9 87,3 351,1 58,5 8,9 11,0 5 140,4 97,7 448,8 57,5 9,8 11,9 6 139,0 104,7 553,5 57,0 10,5 12,7 7 137,7 109,9 663,4 56,5 11,2 13,3 8 136,5 115,2 778,6 55,5 11,7 13,9 9 135,3 120,4 899,0 55,0 12,2 14,4 10 134,3 125,6 1024,7 54,5 12,7 14,9 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 1055 mm including two overhangs of 30 mm The beam's estimated 3dB beamwidth is 37 deg A half wave 4:1 balun uses 0,75 velocity factor RG-6 (foam PE) and is 131 mm long plus leads FOLDED DIPOLE CONSTRUCTION Measurements are taken from the inside of bends Folded dipole length measured tip to tip = 162mm Total rod length =355mm Centre of rod=177mm Distance BC=CD=64mm Distance HI=GF=59mm Distance HA=GE=86mm Distance HB=GD=114mm Distance HC=GC=177mm 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 1570mm of round 4mm rod 2) Length used by single dipole 159mm or folded dipole 355mm of round 8mm rod 3) Length used for boom 1055mm (allows for 30mm each end) round stock 25mm diameter