Ben AI6YRAug 8, 2023
My #hambrella receives fine on 20m! HA! #hamradio #project #hf #antenna
Show threadJohn MacFarlaneAug 8, 2023

@ai6yr @ai6yr what do you do to measure the antenna efficiency- VSWR? How did it do?

Curious to the directionality too.

Show threadBen AI6YRAug 8, 2023
@JohnLMacFarlane @ai6yr I ran an MFJ analyzer on this, as well as a NanoVNA. It's <2.0 SWR on 70cm and 2m, and it is <4.0 SWR on 15m (where it transmits). SWR is too high to transmit on 20m but it receives fine. My suspicion is that the large metallic surface has it acting a lot like a discone.
Show threadJohn MacFarlane
@ai6yr @ai6yr The antenna modelling software is pretty good these days, have you tried modelling it? Might give you some ideas.
Aug 8, 2023 at 2:31pmWeb
Show threadBen AI6YRAug 8, 2023
@JohnLMacFarlane @ai6yr Yeah, maybe throw some approximation of that into EZNEC and see what it spits out