Decals (or keeping your link antenna paint free)

There are many vendors with web sites who offer custom vinyl self-adhesive labels such as the AREDN labels we offer. You can easily specify the size you want an upload the graphic. Small quantities are not overly expensive. Haven't looked into decals, but I expect that they are just as readily available.

There's Brother P-touch labelmakers and some of their tapes are for indoor and outdoor use.  The labels look to be all plastic and maybe not absorb RF.  You could test this by putting some of the tape with something printed on it in a microwave (along with a cup of coffee as a dummy load) and see if the label survives or not. Assuming success, you could make the label say "Do Not Paint, Microwave Antenna". 

I use the Brother P-Touch "Cable Labels" on all of my outdoor AREDN Gear and Ethernet cables on the towers.  So far so good - 1.5 years + and no sign of degredation.  If you aren't aware, the PTouchDirect.com store.  Here is a link to the tape:

http://www.ptouchdirect.com/ptouch/tz631.html

Last time I bought some, I got another one free for every one that I bought.  Not a bad price considering the prices of the stuff from the office supply places.  I think I bought my labelmaker for around $10. (A $50 value).  Wish I got a commission on this stuff, or at least owned stock in the company!

Probably not RF conductive, but there are places you can place the labels that aren't in the way of the antenna panels.

T.D.



 

I ran the microwave oven test on some black on white tape, nothing happened.  Not even warm.  Which would imply that it won't absorb our RF energy.  A thin extra layer of dielectric on an outdoor antenna that's inside a plastic pipe probably won't impact the antenna's SWR and such to any significant degree.

dk & df, dielectric constant and dissipation factor. 

Unless a conductor is fully embedded in the dielectric then the idea is effective dielectric constant. The further away or the more air/vacuum is around that conductor the closer to the dk is to vacuum ==1. 

Low df minimizes loss. Think of df as conductivity so high df or conductivity you do not want. Very low values compared to metals is the cause of excessive loss on a radome. 

So testing in a microwave oven as described is a pretty good indicator of conductivity. Hopefully we are not over simplifying (versus over engineering and complicating), but if it doesn't melt or smoke you are probably good. But, I would still put the strip to the side versus in the center. Two on the sides versus one in the center. Obviously no technical data for that, just me.

-Jeff W9NIZ

I just painted the rounded face of a Ubiquiti 5G Sector antenna with grey Krylon spray paint. Only after painting the antenna with two thin coats did I read the ingredients and notice the paint contains titanium dioxide. I can't find information online, and was wondering if anyone here has had any negative effects from painting an antenna with this extremely-prevalent element? The RF does have to penetrate the paint, and my concern is that the paint will attenuate the signal. Any insights? Facts are preferred but experienced opinions are welcomed.

ALSO: I intend to finish the antenna with a small coat of Dupli-Color Acrylic Lacquer ClearCoat to further protect the paint. Any issues there?

Thanks,

Thomas, KM4TBQ