![]() ![]() So I modified my objectives to create a QRP magnetic loop that, while bulkier than a Miracle Whip, would blow it away in terms of performance yet still be easily portable and usable in all the same situations except walkabout operation. Also, the voltages present across the tuning capacitor, even at QRP power levels, are high enough that a good air-spaced variable capacitor needs to be used, increasing the size and weight of the antenna. The efficiency of a magnetic loop drops steeply as the size of the loop decreases, and you quickly reach the point at which efficiency is so poor that the telescopic whip radiates a better signal. I soon learned that making a magnetic loop the size of a Miracle Whip would be impractical. So began my first experiments with what evolved into the Wonder Loop. My experience with the MFJ magnetic loop led me to be very impressed with this type of antenna, and I wondered whether a better type of "miracle" antenna could be made using the magnetic loop principle. These antennas are small and very portable, but you pay for this with a considerable penalty in efficiency. The idea for the Wonder Loop first came to me after I had tested small portable whip antennas such as the ATX Walkabout, Miracle Whip and Wonder Wand. In its first couple of days of testing the G4ILO Wonder Loop sent a 2 watt signal all the way from northern England to Western Australia. In good conditions the Wonder Loop should genuinely be capable of worldwide communication using low power, particularly if CW or PSK31 is used. Performance is within an S-point or two of a dipole and better than many of the antennas often used in temporary or compromise locations. It needs no supporting mast, and no counterpoises or ground connections are required. The Wonder Loop is the perfect antenna for picnic table or hotel room operation, or for home station use where outside antennas are not permitted and attic antennas not possible. When disassembled the antenna easily fits in a suitcase or backpack. It is designed for portability, and can be assembled or disassembled in about a minute. On a scale of 1 to 5, this kit is rated at 2 depending on your experience.The G4ILO Wonder Loop is an inexpensive, easy to make magnetic loop antenna that covers five HF bands, 40m through 15m. The device can be tied down on the connection end with the hole provided. Depending on the gauge wire you opt to use, the radiating element may be stored wrapped around the device for storage and transportation. A BNC female connector is supplied for connection to your radio. The user supplies the 1/2λ wire for attachment to the captive S.S. Our tests have been favorable for ≤2.0 SWR or better for the entire band, except 80m, which can be optimized for the upper or lower portion of the band. It is designed to use without a tuner and give an SWR of ≤1.2 for any portion of the band after optimizing the driven element. The SWR is further broadened and lowered across 80m-10m with a high voltage capacitor on the primary of the transformer using band specific radiator lengths. The high impedance, half wave wire is matched to your 50 ohm feed point by an integral impedance matching toroid transformer, and rated is at 20 watts. Your feed line is essentially the counterpoise, so a separate one is not needed. ![]() It is designed as a highly portable wire antenna, easily set up as an inverted V, horizontal, sloper, or in the case of higher frequencies, a vertical radiator. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. Any you see there are counterfeit and contain very substandard toroids. We do not sell on AliExpress, eBay, Walmart, or Amazon, even if it uses our name and logo. This product is sold only on this website. QRPGuys Portable No Tune Half Wave Antenna – $30 ![]()
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