In November I set up the Asymmetrical Hatted Vertical Dipole (AHVD) for the CQ-Worldwide-CW contest. I could only set for one band so I choose 10 meters (hereafter known as the AHVD/10m) to complement the 43 Foot vertical.

The AHVD performed reasonably well and was the go to antenna for ten meter contacts. I constantly switched back and forth between the 43 foot and the AHVD/10m. It really isn’t remarkable news a dedicated 10m vertical dipole beats a 43 Footer at 10m, but at least I now have A/B comparisons to confirm the theory.

Note, the AHVD was indeed better than the 43 Footer, but not by all that much. The difference appeared to be 1/2 to 1 S unit… not much at all.

Next I participated in the Ten-Meter RTTY contest last weekend with good success. Again comparisons between the AHVD and 43 Foot suggest the AHVD wins by a small, but consistent margin.

This morning an ice storm hit Virginia and the AHVD gained its share of ice along with everything else in my yard.

AHVD and Ice

AHVD with Ice

It certainly is a sight isn’t it. I wondered how the antenna would stand up to the ice load mechanically, but finally remembered the AHVD with the 10m dimensions has a lot of overlapping aluminum resulting in a ultra strong assembly. Those using the AHVD for 20m should evaluate if they should take the antenna down during ice storms.

After I took the photograph, I sat down in the shack to see if it still worked. I didn’t have a VNA handy to measure SWR, but did pay attention to the IC-746 SWR meter for some clues. It was indeed a little different than before, but the very wide bandwidth of the antenna design preserved good antenna behavior.

I made a few contacts on 10m to check things out. The band was somewhat active so I had no trouble earning a few QSOs with 100 watts or so into the AHVD including this one with W7GVW in Montana. He was using a Hexbeam pointing east. I heard him 59 and he heard me 58. Eventually QRM covered my transmission to him even though his signal remained consistently strong. It was a nice long chat while it lasted.

So the AHVD seems to work well enough with an ice load. I really wish I had a VNA handy though as I have long wondered how ice really affects antenna parameters. Next time perhaps.

73
John

About John Huggins

John is an electrical engineer working in astronomy and aerospace including 33 years in antenna/RF design with experience modeling, manufacturing and measuring past, present and new antenna concepts.

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