24-05-2024, 12:23 AM
Hi there,
I'm slowly building up some DIY test gear - if I build a thing for use at work, I try to build a spare for myself at the same time.
Next on my list is a biconical antenna. We want to do some EMC testing on some gear, and although we could buy or hire one the idea of just making the thing is pretty appealing. I've now got a couple of LISNs via github->kicad->china for the same reason. They've already been handy in finding conducted EMI, which was nice.
I found the original drawings in MIL-STD-461A (from 1968, when they included useful detail in standards!), and it seems fairly straightforward - particularly in this brave new world of just sending a .stp file away and getting back cnc'd aluminium for the bases and caps.
The only part I'm slightly less confident about is the balun, though it looks like passing coax through a few toroids might do the trick, or perhaps wrapping it about a ferrite core. I base this on a commercially available biconical referring to using a 'modified guanella' balun.
Has anyone built one and had a bad time? Anything to avoid or things to know?
Cheers,
Scott
I'm slowly building up some DIY test gear - if I build a thing for use at work, I try to build a spare for myself at the same time.
Next on my list is a biconical antenna. We want to do some EMC testing on some gear, and although we could buy or hire one the idea of just making the thing is pretty appealing. I've now got a couple of LISNs via github->kicad->china for the same reason. They've already been handy in finding conducted EMI, which was nice.
I found the original drawings in MIL-STD-461A (from 1968, when they included useful detail in standards!), and it seems fairly straightforward - particularly in this brave new world of just sending a .stp file away and getting back cnc'd aluminium for the bases and caps.
The only part I'm slightly less confident about is the balun, though it looks like passing coax through a few toroids might do the trick, or perhaps wrapping it about a ferrite core. I base this on a commercially available biconical referring to using a 'modified guanella' balun.
Has anyone built one and had a bad time? Anything to avoid or things to know?
Cheers,
Scott