Posts by St2nh

    Because I have no hardware to check for the SWR, I tried many different kind of antennas ,looking for the best performance.

    I home-browed many kind of antenna for the uplink, eg, patch antenna a helical antenna with flat matching strip etc. the performance was poor.


    The last one I was built is a helical antenna with a triangle strip. the perform is much better comparing to other antennas .

    My signal report jumps to 58-59 !!.


    I built it around an empty toothpast pump tube :-)

    D=4 cm.

    Space between turns 28 mm.

    Number of turn 3.

    The strip is right angle trangle 71mm*17mm one corner attached to to the SMA pin on flat Alu reflector - dimention 12 cm * 12cm .

    The tube clued by epoxy at the front side ,plus the nozzle of the tube pass throught a hole at the center of the reflector.

    Dish =1 meter.


    Here are the links I was used.


    http://f5ad.free.fr/Liens_coup…A3FYM%20Helice%202300.htm


    https://www.qsl.net/oh4jzj/13cmhelixframe.htm









    73 de Nader / st2nh

    Thanks DD0KP Heiner & DD1US Mattias.


    Other question!!


    I got EDUP mode EP-AB003 wifi amp.

    Since out of the box ,It’s never got hot or improve my signal ?!!!

    I did some modifications to increase the power . Fixi a jumper as in the photo...

    The result is only heat but no improvement in power !!


    Pin 4&5 jointed in permanent tx mode.

    Current constant during tx or rx mode.

    Any advice or it’s a dead amp??



    Vy 73