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Author Topic: Paint on a yagi  (Read 931 times)

KK4GMU

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Paint on a yagi
« on: July 24, 2022, 01:47:39 PM »

A separate "stealth yagi" topic to satisfy my HOA:

I read that if an antenna is to be painted to help it become stealthier, it should be painted with a "non-metallic" paint.

Does that same advice apply to a metallic antenna?  It's already metal.  It's counter-intuitive to believe that a 0.2mm of metallic paint can adversely affect the performance of an already metallic antenna.

What is the best advice regarding painting a yagi?
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K6AER

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Re: Paint on a yagi,
« Reply #1 on: July 24, 2022, 07:34:12 PM »

I have had SteppIR antennas for over 20 years . After ten years the color is gone from the fiber glass poles and I will just paint the antenna with acrylic paint. The tuning lengths don't change.

As far as painting an antenna to make it stealth, it never works.
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K0UA

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Re: Paint on a yagi
« Reply #2 on: July 24, 2022, 08:49:48 PM »

I have painted mine with clear Krylon for years. Just to help prevent corrosion. I have painted the fiberglass portion of my ancient Hustler G6 2 meter antenna with gray paint to keep it from delaminating. Doesn't hurt a thing.
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73  James K0UA

W0RW

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Re: Paint on a yagi
« Reply #3 on: July 25, 2022, 05:42:44 AM »

i always paint my T Hunt yagis black.
It keeps the jammers from seeing it until it is too late.
i paint my base antennas green to blend in with the trees.
Paul   w0rw
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WB6BYU

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Re: Paint on a yagi
« Reply #4 on: July 25, 2022, 09:51:41 AM »

Metalic paint may make a difference if it creates a short across an
insulator, or creates a shield on the outside of the fiberglass tube
that protects a VHF/UHF antenna.

But the "metalic" paints I've seen aren't actually conductive,
they just have sparkles of metal in them.  It might produce
some dielectric loading effects in certain cases that would
shift the resonant frequency slightly, but otherwise I doubt
it would make much difference.


Probably isn't the best choice for making the antenna less
obvious, but I don't know the background color scheme of
your house...

WA3SKN

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Re: Paint on a yagi
« Reply #5 on: July 25, 2022, 11:47:16 AM »

The real question is... "is the paint conductive?".
Say you have a plumber's delight constructed yagi... metal elements with metal boom and connected.  It will do no harm to put conductive paint on the parts.
Now if you have insulated parts and you put conductive paint on you might have a problem.
Make a test patch with the paint and let it dry, then measure the DC resistance with an ohmmeter.  As long as the resistance is at least 10 times the impedance you are bridging you should be OK.
But paint rarely "hides" an antenna. So you should ask "do I have to?" when painting antennas.
Remember it is messy to get off!

-Mike.
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W1RKW

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Re: Paint on a yagi
« Reply #6 on: July 25, 2022, 12:40:58 PM »

think red and white AM radio tower.
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W1VT

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Re: Paint on a yagi
« Reply #7 on: July 26, 2022, 07:00:50 AM »

I recall getting a report that Rustoleum camo paint caused a high SWR about a year ago.
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K1KIM

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Re: Paint on a yagi
« Reply #8 on: July 26, 2022, 07:40:19 AM »

"Metallic" paint on a "metal"antenna has no effect other than to change the color.

I think the jury is out on whether it affects the radiation of a fiberglass antenna (which is just a metal antenna on a fiberglass sleeve).

The only way I have seen paint to be conductive is to make my own to shield the cavities on an electric guitar. That paint I make of carbon powder and clear lacquer. Heavy on the carbon!
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GEORGEMINK

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Re: Paint on a yagi
« Reply #9 on: December 11, 2022, 06:09:35 AM »

I'm living under a restrictive HOA and have been inclined to keep everything in the attic. But I just purchased a Moonraker GPA-80 and have it mounted over a 5 gallon concrete filled bucket on a removable PVC pipe in my back yard. I thought at 20' and without any traps that the skinny little antenna would not be noticeable but even with my 6' privacy fence it stands out pretty bad from the road. I think mainly because it's shinny, even at night the street lights reflect off of it.

So, I'm going to paint it with some flat paint. Just wondering who hear has had any experience with trying to "Camo" their antenna and how did it work out? what color did you use? I have several cans of camo colored paint already in FDE, Dark Brown, and Olive Drab. Black has been mentioned too. 
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W6IBU

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Re: Paint on a yagi
« Reply #10 on: December 11, 2022, 08:29:37 AM »

If you're worried about conductivity, test the paint in a microwave for a bit and see if it gets hot.  I've heard that works.

73, Paul, W6IBU
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WB6BYU

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Re: Paint on a yagi
« Reply #11 on: December 11, 2022, 08:41:36 AM »

Generally I’d use black, but if the background
neighbors will see it against is mostly trees,
then a brown/green paint job might work.

The wire HF antenna on my roof is #26 brown /
green insulated hookup wire.  When hams come
to visit I walk them right under it and tell them
to look up.  It is very difficult to see from the
road unless the sunlight glints on it, or it
has a coating of frost or snow.

W7CXC

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Re: Paint on a yagi
« Reply #12 on: December 11, 2022, 08:48:37 AM »

Flat battle ship grey is quite effective. (Krylon)
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K5LXP

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Re: Paint on a yagi
« Reply #13 on: December 11, 2022, 11:20:39 AM »

I painted a vertical flat black for a guy that had it set up in an HOA.  It was literally impossible to see from the street, it vanished against the vegetation and structures.  But a yagi up in the sky is pretty hard to hide.  There are some commercial verticals that come with a sky-blue radome I've seen but that's like the fake evergreen tree cell phone antennas.  Might be less visually "offensive" but there's no hiding an antenna on a mast or tower.

Mark K5LXP
Albuquerque, NM
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K5TED

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Re: Paint on a yagi
« Reply #14 on: December 11, 2022, 11:24:55 AM »

I use self etching spray primer on my aluminum and white fiberglass verticals. It's a flat gray/green, and in mostly invisible from a block away. Not conductive to any extent that would affect the antenna performance that I can tell.

https://painttopics.com/what-is-self-etching-primer/
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