Other SOTA sites: SOTAwatch | SOTA Home | Database | Video | Photos | Shop | Mapping | FAQs | Facebook | Contact SOTA

SOTA Vertical Antenna for 40-30-20m


#21

Hi, if the buildung volume (140 mm in all directions) is sufficient, I can very much recommend this one:

The bigger models are also good.

73 de Martin, DK3IT

Edit: Great to see @N4CCB printing my antenna design - I learned a lot from your videos!


#22

Actually, the picture is mine, I’m printing your designs! Although, for my needs I’ll need to tweak your design because my masts have a larger diameter than yours. I had to give credit to N4CCB because he got me over the intellectual hurdle of taking on 3D printing. I also learned a lot from his videos, and asked if he’d make me a part from his portable hexbeam. He responded by saying just buy a printer. I wouldn’t do it for $1000, however $200 is low enough to draw me in. Now that I have it, it’s a bit of a game changer for homebrewing.


#23

One of you guys should start selling those coil forms if we could all agree on a mast size :grinning:

I like Martin’s idea of placing the coil about 2M above the ground

very cool work all you 3D printers!

73, Barry N1EU


#24

Hi Barry,
thanks - two comments:

As for the mast size: That is the crux of this design - it must fit tightly to the mast at the appropriate height above ground. You can use rubber bands to make it stay at the desired position with rubber bands if the mast is smaller. A more elegant solution would be a set of adaptors that match the mast diameter to the antenna coil diameter.

As for the coil position higher above the ground: I tried that, but the gains in performance where insignificant, and the loss in ease of handling were severe. So I abandoned that idea. I think that resonant elevated counterpoises make for a much bigger effect than the position of the coil.

73 de Martin, DK3IT