I just printed a Moxon Antenna and want to wire it. The Antenna wiring has a blank space and I'm not sure how to wire this place. From picture bellow I got that I need to connect a coax shield to top's one arm and conductor to another.

But both arms has 17mm space where I can't fit the wire. What is this space? When I just insert wire to as shown at the picture wire will not be connected to coax cable, is it okay?

Moxon Antenna

my type

  • 1
    $\begingroup$ Plastic in close proximity to the antenna affects the element length slightly. If you have changed the amount of plastic in the design from someone's original, you may need to reduce the element lengths, for this you need a network analyser. If it has already been tuned for this much plastic then it should be fine. $\endgroup$
    – tomnexus
    Feb 23 at 17:03
  • $\begingroup$ @tomnexus, I agree with your comment, but would like to add there are many different plastics, each with it's own dielectric coefficient. (capacitance generating capacity) Many plastics(or fiberglass) have negligible impact. The network analyzer helps with the spacer selection and ground and some aspects of near field refection influences. $\endgroup$
    – user23328
    Feb 25 at 4:03
  • $\begingroup$ @strom true there are many plastics with different characteristics, glass fill and black carbon have the biggest effect. What I really meant was - if this is scaled down from an HF antenna with no plastic, then it will definitely not work with that much plastic around it (any kind). It will be pulled 5 or 10% lower in frequency, more than its bandwidth. But if someone has designed the wire+plastic to work well together, then it will be fine. (and even if you change from PLA to ABS etc). $\endgroup$
    – tomnexus
    Feb 25 at 5:40
  • $\begingroup$ I understand black carbon as both graphite and "carbon fiber" have partial conductivity leading to inductance, glass fill would have the opposite effect . At a 17 mm spacing, The effects of any parasitic capacitance or inductance introduced may reduce bandwidth, but not enough to hinder proper function (SWR) in the operating range. $\endgroup$
    – user23328
    Feb 25 at 6:20

1 Answer 1


There is no connection in the 17mm space. The wire that sits in the 46x249x46 space is simply a "reflector", and has no connection to the other wires, which are considered the "driven" elements (driven by the connection to your two conductors coming from your transmitter).


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