***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 12, 2009

Tribander Dipole - Homebrew again

Today i have time to make this antenna again..after DAL convinced me to make this antenna..i make 2sets..1set already booked from our member from northern of peninsular Malaysia..got another set readymade open for any kind of members want to try this antenna..after completed, tested with swr meter..the results at 40m & 20m are 1:1.7, at 10m is 1:2..so, at 40m & 20m band no need tuner because 1:1.7 are still acceptable to use..for 10m need to use tuner..this idea coming because of the area, in certain extend, our area doesn't sufficient, so this is the suit antenna..one more thing is Portable antenna..this antenna design purposely for those want to set up Portable station like at village, trip field day etc..

2sets of Tribanders Trap Dipole

Close-up

Feeding Point

Close-up

Thank to all members give support either direct or indrectly..

73 from 9M2ODY

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1 comment:

  1. AnonymousDecember 19, 2009 at 3:02 PM

    Hello Ody, 9M2ODY,

    Congratulation for having shortened antenna like this. In small space, indeed we need short extent. Longer the radiator, efficiency (gain) would be higher, and vice versa: shorter the radiator, efficiency (gain) would be lower. I have better idea: for limited space, You could make linear loaded antenna which gain between halfwave dipole and trap dipole. Idea of linear loaded antenna is not to cut radiator length and compensate it with loading coil, but to fold whole halfwave so total extent not too long.

    About SWR, it is important to make SWR (PSWR) shows exactly 1.0, means your antenna impedance matches with transmitter impedance. If SWR more than 1.0, then there should be portion of power reflected back from antenna to transmitter. Use of antenna tuner should be avoided. There are several antenna impedance matching systems could be utilized, eg. gamma match, transformer balun, etc..

    Impedance of antenna which is shorter than it supposed to be is R-jX (capacitive character), then impedance matcher should be in R+jX (inductive character).

    Vice versa, impedance of antenna which is longer than it supposed to be is R+jX (inductive character), then impedance matcher should be in R-jX (capacitive character).

    Thank You for beautiful QSO today. Hope to hear You again soon.

    Sincerely Yours, Roosdiarto Rooskandar, ST., YG1CRR

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