Enclosing the Pixel Loop Antenna (aka: DX Engineering RF-PRO-1B Active Magnetic Loop Antenna)

W9AT

With several other FlexRadio users using active magnetic loop antennas, I wanted to ask the group for thoughts on covering/housing such an antenna (3ish feet in diameter) on a rotator.  Envision this enclosure atop a building, on a short mast, or even sitting within a few feet of the ground.

A radar unit radome-type of enclosure is just one example.  A wooden box (no metal at all) is another idea.

Knowing that metal close to my loop has had a significant impact on performance, I brainstormed non-metallic housings that are “rf-transparent”.   (I realize that precipitation on the outside of the housing would also have an impact, but I can envision no way to stop the rain from sticking—except maybe spinning at high speed, but I digress).  After dropping the inflatable “balloon” housing idea <grin>, I pretty much was left with ideas involving wood and/or fiberglass.  Design-wise, I’m sure it could be conceived if needed to blend in better than the bulbous white sphere that “radome” brings to mind.

 Questions for the group:

1.       Has anyone built or otherwise obtained an enclosure for their active magnetic loop on a rotator (other than inside an attic:  too much metal around for me)?

2.       What are your thoughts/suggestions on “rf-transparent” materials for an enclosure?  (e.g.  at HF, is wood really rf-transparent?  Other materials?)

The experience and imagination of the group is valuable.

Thank you for the time of your consideration and any reply! 

Mark W9AT

KY6LA_Howard

Question;,,,WHY? You understand that any encloute will increase the wind load

W9AT

Reasonable question, Howard. 

a.  Aesthetics
b.  Protection from the elements (including snow/ice build-up)

As this would be within 10' of the ground or based atop a building (becomes part of the building), wind load is less important than with other deployment scenarios like a tall mast/tower).

KY6LA_Howard

It's not very big

Ian1

Mark There is no reason other then change the looks for such a project. My 2 cents says focus your efforts elsewhere. Ian

Steve K9ZW

@Mark W9AT

It would seem that most any enclosure with a limited amount of metal would suffice.  Participated professionally in the design-build of a completely RF transparent but conventional appearance commercial building in your metroplex (testing facility) and if the building envelope couldn't use non-metallic components the designers used extremely limited amounts of aluminum and stainless.

Listening to discussions whether the copper content of modern treated lumber changes the wood's RF permeability I couldn't come away with any conclusions. 

Yet as the Pixel Loop user reports indicate successful operation in wood stick framed structures, it would seem there would be a lot of pre-engineered structures that could be used. 

Seems the trick would be to not massively shield it with metal, at least in the directions you hope to listen to.

I've considered moving my Pixel Loop and rotor to a shed, thinking I'd purchase one of those injection-molded plastic ones.  A few years back we put a repeater in one, and it has held up very well while looking like just another part of the "domestic landscape" rather than industrial.

73

Steve K9ZW

Mark NS9N

I have had my loop up for years about 4 feet off the ground in Chicago winters. Never thought about enclosing it. Great lawn art the way it is. I would also agree spend your time other places.

W9AT

Thanks for the time in reading and thoughtfully replying Steve. 

Mark W9AT

Andrew VK5CV

Mark,
Here is my loop on the chimney of a California Bungalow.
TV type rotator. Though I rarely need to rotate it.
No snow here though with South Australia being just like California.

Andrew VK5CV

Steve K9ZW

Guys, living in the upper (USA) Midwest is a bit more adventurous for weather. Some QTH photos: During a season Winter Cold will get at least-20F/-30c, High Winds will hit 60mph/100kph, and snow on the ground will reach 40in/1m. We get real summers too with 100+F/40c temps, tornadoes occasionally and lots of thunderstorms in season. True four season weather. You shelter what you don't have to leave out, especially if it has moving parts, rotates or is something less than MilSpec build quality. These are not extremes, as I've been snowmobiling at -40F/-40c with -100 wind chills and our neighbors to the Canadian north would have considered my conditions a heat wave. 73 Steve K9ZW

Steve K9ZW

I should have added the snow can drift car high, and the deep cold can stick for weeks and weeks. But the sky is fantastic. Sometimes the Aurora shows and winter sports, hunting and ice fishing are seasonal treats. It ends up so awesome - hard to explain. Truth is, living here even becomes hard to explain to one living here when you're in the midst of an emergency repair at -25. That is until you live away and can't wait to get back. 73 Steve K9ZW

AB9UU

I have had mine up on roof several years in Chicago.  I did have to replace the amplifier on it recently as it died.  Perhaps, enclosing the amp would have prevented or delayed the demise but I am unsure.

N0AZZ

My Pixel Loop "original one" not DXE has been up for over 6 yrs. with a Radio Shack rotor and never had a single issue with it other than ice buildup and any enclosure would have the same problem. I agree with work on other areas instead.