In sci.electronics.repair, on Wed, 11 Oct 2017 08:07:50 -0700 (PDT),
wrote:

On Wednesday, October 11, 2017 at 2:46:30 AM UTC-5, Andy Burns wrote:
micky wrote:

The antenna that came on my 2005 Toyota is about 16" long and the top
ten inches have a wire coiled around in it, like the snake on a
caduceus. Does this wire do anything or is it just to impress people?

https://en.wikipedia.org/wiki/Helical_antenna

Actually, I don't believe that is the purpose. I think I've read that on automotive antennas, the winding is simply a means to reduce wind induced oscillation and noise.

Terry

Well, either one is a good reason and I'm glad to hear that there is a
reason.

It's triply important to me to reduce wind noise becausethe car is a
convertible, and I'd hear any noise it made, but I should mention that
this is my 8th convertible over 50 years and all the other ones had
standard antennas, usually in the front** but sometimes in the rear, and
I never heard any noise from them. I used to drive on the highway at
75 or even 80, but noise was the reason I dropped my max to 65. Noise
seemed to increase sharply over 65mph. So I do notice this, but it
wasn't noise from the antenna. It was wind in general, and it applied/s
whether the top was up or down. (although later cars have had a top
liner, and maybe they would be tolerable above 65mph.) The previous
car, also a Solara, a 2000, had a standard electrically retractable
antenna, also in the right rear fender, and no noise that I've noticed.

So maybe Toyota says it will be more quiet but it's just a gimmick. If
so, that would just be my second choice, "to impress people".

I still have the previous car until I get the new one repaired if
necessary and inspected, so if I can, I will take out both the old and
new ones and go 80 for a while and see if I can hear a difference. The
old one needs a lot of work but it's still as quiet as it ever was, as
the new one is.

**One or more GM cars didn't have the round antenna that deliquents used
to break off. It's cross-section was shaped like a football. At the
very least, it prevented the antenna's use for zip guns. Another was
just a wire, not telescoping, not retracting. No one ever broke my
antenna however, and the fad seems to have gone away. The custom of
slashing tops and tires of cars whose owner one doesn't know and even
when not trying to steal eanything seems to have also disappeared.