KO4YAW Read Bulletin

Message 21540 in TECH.WW

From: G8MNY
Date: Tue, 28 Apr 26 06:41:00 Z
Newsgroups: TECH.WW
Subject: 4m 5/8 Vertical
Message-ID: <58302_GB7CIP>
Path: N2MH4|N3HYM|W0ARP|VK2RZ|GB7CIP

R:260428/0647Z 30678@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260428/0647Z 3385@N3HYM.#FRDK.MD.USA.NOAM BPQ6.0.24
R:260428/0646Z 38203@W0ARP.#NCO.CO.USA.NOAM LinBPQ6.0.25
R:260428/0646Z 14671@VK2RZ.#SYD.NSW.AUS.OC LinBPQ6.0.25
R:260428/0641Z @:GB7CIP.#32.GBR.EURO #:58302 [Caterham Surrey GBR]

From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

From: ANDY G6OHM@GB7HOL.#22.GBR.EU                    (new Nov 04)

             FIVE-EIGHTHS VERTICAL FOR 4M
             ============================
THE ANTENNA IS BASED ON A DESIGN FROM THE ARRL HANDBOOK.
THE ANTENNA IS MADE FROM AN OLD CB ANTENNA.
THIS ARTICLE WAS TAKEN FROM THE 4M NEWSLETTER WRITTEN BY G7RSD.
                 __
                 ||
                 ||
                 ||
                 || 
                 ||                     |    |
                 ||                     |    |
                 ||                     |    |
            ^    ||                    B|____|
LENGTH TO TOP    ||                      |//|   7 TURNS 16 SWG
 OF COIL       > ||                      |//|   COPPER WIRE ON 22MM
  2680MM         ||                      |//| < DIA GRP TUBING.
                 ||                      |//|   10 MM BETWEEN TURNS,
                 ||                      |//|   APROX.
                 ||                      |//|   LENGTH OF GRP TUBE
                 ||                      |//|   130 MM.
                 ||                      |//|  COILS SELF TAPPED ONTO
                |  |                     |//|  ALLI TUBING EACH END.
                |  |               _____B|//|
                |  |               I    |----|< RUN COPPER WIRE TO
                |  |               I    |    |  UHF SOCKET.SELF TAP
                |  |              MMM***|    |  BRACKET TO ALI TUBE
                |  |              MMM  *|    |
                |__|                    |    |
                 ||
                 || < COIL
                 ||
                 ||
                 ||           CIRCULAR GROUND PLANE 270 MM DIA.6mm ROD.
             I---||           GROUND PLANE MADE IN A SPIRAL .THE FREE END
       //////I//////////////  IS JOINED BY A SHORTING BAR TO THE BOTTOM
             I  |--|B///////  ROD JUST PASSED WHERE THE ROD COMES OUT
           MMM**|  |          OFF THE BOTTOM ALI SECTION.THE BOTTOM ALI
           MMM *|  |          SECTION LENGTH IS 400MM.
               *|  |          YOU WILL NEED AN ADJUSTMENT AT THE FREE END
        ///-----|  |          OF THE GROUND PLANE TO HELP VSWR.
        ///-----|  |
        ///     |  |
        ///     |  |
        ///     |  | < 400 MM              270 MM DIA CIRCLE
        ///_____|  |                      ...................
        ///_____|__|                      .                 .
        ///                               .                 .
        ///                               .       00        .
        ///                               .        I        .
        ///                               .        I        .
        ///                               .        IIIIIIIII.
                                          .............//...
                                                         ^
                                            // INDICATE SHORTING BAR &
                                            EXTRA PIECE FOR ADJUSTMENT

         LENGTH OF ROD TO MAKE CIRCULAR GROUND PLANE IS 1070MM

73 - ANDY, G6OHM @ GB7HOL


Why Don't U send an interesting bul?

73 De John G8MNY @ GB7CIP




← Return to Bulletin List