***de 9 Mexico 2 Ocean David Yesterday***
"Work active at 10m, 20m, 30m, 40m, 80m & also 2m band..all band worked at FM, SSB & PSK31 also CW modes..hpe can see u down the log & highly appreciated to work with me at the band"
"I'm worked seriously at 10m, 20m & 40m on my HF mobile station right now, please do not hesitate to answer if u hear my call, i'm always calling CQ DX during mobile"

Saturday, December 4, 2010

Dual Band Trap Dipole 40/17

Due on the unforeseen circumstances, i have to bring down my Tribander Trap Dipole (40/20/10) & change to new one..do this Dipole with patient today, really give me very nice VSWR, which is value 1:1 from 7.000mhz to 7.090mhz..very happy with this result..waiting for RST from any stations soon..the theoretically on 40m (7.000mhz) really impressed (no tuner) & on 17m (18.150mhz) the VSWR is 1.6:1 & still ok..traps design using Coaxial Trap Design to get the resonant on 17m..now ready to hunting on 17m..hi hi..hope to see you soon at 17m band..

Coaxial Trap Design software

RF Choke 1:1 'ugly balun'

View inside Trap



RF Choke 1:1 'ugly balun' in action

Dipole on the air

lovely Tribander Trap Dipole

Formula Calculations as follow :

A = 72 / Mhz (72/18.150 = 3.96m)
B = 72 / Mhz x 0.83 (72 / 7.100 x 0.83 = 8.41m)
C = B - A (8.41 - 3.96 = 4.45m)
Trap Design = 5turns RG58 on 40mm dia. pvc pipe

VSWR on 7.043mhz = 1:1, 7.130mhz = 1.2:1

73/88 de 9M2ODY

1 comment: