Newbie needs advice on patch feed

  • Hi there,

    i am new to frequencies like these , coming from the other end of the ham radio spectrum , DC for most people here .

    I greatly failed with my first attempt to build an antenna not made of wire at least 40m long, hi. I built the patch feed antenna, probably with the wrong dimensions. My question is: Can i use the dimensions given by G0MJW in this thread and not drill a 22mm hole ( won't need it) . Instead, i would use a screw and nut in the center for adjusting the distance between reflector and patch. Can i do that? Will the dimensions be the same? Thanks.

    73, Martin

  • Thanks Remco.

    Is this proven? My first antenna was according to the dimensions K3TZ gave, but was well below 2.4 Ghz, at least 800Mhz. Maybe i made a mistake somewhere.

    Is the diameter of the reflector critical? The design by 7N... says 100mm, K3TZ says 4inch (101,6mm).

  • Ok, i re-built the Antenna. If i'm lucky, DJ8LC has some spare time for the measurements. Lets see. Actually , i was not 800Mhz low, but about 180 Mhz and the match was no good.

  • dm4im I have no experience with the 'plain' K3TZ patch, so I can't help you directly. However, I made 10 dual band patches and they matched fine. So, why don't you build one according to the 'dual band philosophy' and spare yourself an extra dish?

  • Today DJ8LC and me measured the re-built antenna according to .The match was a lot better and closer to the desired frequency. I didn't fix the patch to the reflector but only glued 2 spacers on the patch so i could rotate the patch while measuring. The place of the spacers have a great impact on the match. We rotated the patch until we got a return loss about 20dB on 2400Mhz. Then we placed the antenna in it's final box and measured again. 26dB.... Done!

    The antenna is placed in the lid of the box, the box presses the antenna down to the lid when screwed on. Now i need to seal the hole where the n-socket protrudes the lid. see some pictures and a HowTo

    Now desperately waiting for the transverter from LZ-Land. 73, Martin

  • Hallo....

    this is the simple patch i used for my tests until now... (K3TZ design)...

    build in a 60cm PF Dish and working nice...

    can read my ssb signal with 0.5W (easy) and worked on FT8 in QSO down to 0.1W tested decodes 0.05 and 0.025W (QRA64) .... so i think not much is wrong here in this design...

    EASY and very CHEAP to build!

    73 de michael dg0opk