{"id":28483,"date":"2017-09-26T07:00:08","date_gmt":"2017-09-26T11:00:08","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=28483"},"modified":"2017-09-25T20:48:49","modified_gmt":"2017-09-26T00:48:49","slug":"a-review-of-the-w4op-portable-magnetic-loop-antenna","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2017\/09\/a-review-of-the-w4op-portable-magnetic-loop-antenna\/","title":{"rendered":"A review of the W4OP portable magnetic loop antenna"},"content":{"rendered":"

The following review first appeared in the August 2017 issue of The Spectrum Monitor<\/a> magazine.<\/em><\/p>\n

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The W4OP Magnetic Loop Antenna (Photo Credit: LnR Precision)<\/p><\/div>\n

What can one say about portable antennas? They\u2019re up, they\u2019re down, they\u2019re basic in design: \u00a0they either work for an intended purpose or they don\u2019t. \u00a0But, I wondered, could they provide their service easily and conveniently, even in the field?<\/span><\/p>\n

Last year, I decided to purchase a portable field antenna, and at the Dayton Hamvention I became the owner of the three-band (40\/20\/10) EFT Trail-Friendly antenna from LnR Precision<\/a>.<\/span><\/p>\n

Then, I caught a bug: the National Parks on the Air (NPOTA) bug. And, wow, I caught it in a bad way…! Having activated seven sites during the 2016 Dayton Hamvention with my buddy Eric McFadden (WD8RIF)<\/a>, I found NPOTA the perfect excuse to play radio outdoors. Last year, from August to December, I activated all but that initial seven of my ninety-one NPOTA park activations. All of these activations were QRP and all of them were \u201cfield\u201d activations; meaning, I set up my field antenna each time; <\/span>no activations were made with a mobile (vehicle) HF installation. <\/span><\/i>\u00a0And I made 85% of all of my activations using LNR\u2019s EFT Trail-Friendly antenna.<\/span><\/p>\n

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The EFT Trail-Friendly antenna is incredibly compact and quite easy to deploy.<\/p><\/div>\n

The EFT Trail-Friendly antenna is end-fed and requires some sort of support system to raise the end of the 33\u2019 radiator. Most of the time, I simply hung the lightweight EFT from a sturdy tree branch. On a few occasions, I hung the end on a 31\u2019 or 22\u2019 fiberglass telescoping pole. I was altogether pleased with its performance; indeed, I can\u2019t recommend it enough for someone who wishes to have a simple, roll-up, resonant antenna for QRP field work. But it does have one limitation: it requires that source of external support, which I worried could undermine some NPOTA activations.<\/span><\/p>\n

In December 2016, my buddy Eric (WD8RIF) and I organized a mini NPOTA DXpedition in Ohio. \u00a0I decided that en route to Ohio, I\u2019d make a run through West Virginia and activate some relatively rare parks along West Virginia\u2019s mighty river gorges. <\/span><\/p>\n

Eric had made the same activation run earlier that year, and had advised me that when I seek permission to activate these parks, I would be asked to apply for and pay at least one, sometimes more, \u201cspecial use permit\u201d fees merely to drape the lightweight EFT antenna over a tree branch or to stake a fiberglass support pole in the ground. Even if my equipment is less invasive in the great outdoors than the poles and stakes of a basic pup tent, I understood US park trees and shrubs can be delicate, rare, or endangered, and even park soil can be, for example, geologically or archaeologically sensitive, so of course I didn\u2019t want a mere antenna to bring about any harm\u2013\u2013however minor\u2013\u2013to the parks I was enjoying. <\/span><\/p>\n

Eric had simplified this step by strapping a fiberglass pole antenna to his vehicle, thus avoiding either penetrating the ground or using park vegetation as a support. \u00a0So as not to potentially harm sensitive park environs, nor be obliged to hop through time-consuming (and expensive) administrative hoops, I decided I would adopt an option similar to Eric: I would use a portable antenna that could stand on its own, thus not requiring external support from park property. <\/span><\/p>\n

Enter the W4OP magnetic loop antenna<\/span><\/h2>\n

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LnR precision had only a few weeks before announced their new portable, self-supporting, magnetic loop antenna: the W4OP loop<\/a>\u00a0($329.99 US). <\/span><\/p>\n

I contacted LnR in November to tell them about my upcoming December NPOTA DXpedition, and inquired whether they thought the W4OP loop would be a good fit? They responded by sending me a loaner unit to both use and review. After all, what better way to evaluate an antenna than by using it in the field? \u00a0I said I\u2019d be happy to give it a test drive. <\/span><\/p>\n

The W4OP loop arrived in early December, about one week before my trip. <\/span><\/p>\n

Contents of the loop package are straightforward:<\/span><\/p>\n