The PreciseLOOP EXPRESS Magnetic Loop Antenna (MLA) is a lower cost model that includes just the basics but with the same high quality and performance.
The Express Magnetic Loop Antenna (MLA) is a convenient, lightweight antenna, which can be deployed quickly and is ideal for use in places where HOA restrictions make full size wire antennas impossible, or where there just is not enough room to erect a conventional antenna. Many operators favor the MLA for field day and SOTA operations. When designed and constructed properly, a MLA can perform as well or even better than a dipole antenna. A MLA is a very simple antenna. It is just an inductor formed by a wire loop and capacitor tuned to resonance. How well this antenna works depends on several factors: The PreciseLOOP EXPRESS is optimized for portable operations featuring greater power handling capability (45W PEP), a precision 6:1 reduction dial with calibrated dial marking, a high surface area 38″ LMR400 radiation loop and copper tube induction loop. Included in the package are the LMR400 radiator loop, copper coupling loop, HG-1 tuner, three section PVC mast and basic bag. (not included are the tripod and adaptor, cables, and premium embroidered padded carrying bag).
Check this video from Greg VA7BC
Low Loss Tuner
The tuner is the heart of any MLA. The capacitor must be very low loss with high Q. It must have sufficient high voltage rating to handle the designed power. The PreciseLOOP HG-1 features a custom dual stator high Q air variable capacitor driven by a 6:1 reduction dial along with calibrated dial markings.
High Quality Components
The components are mounted on a high quality PCB. This insures ideal impedance match, low losses, and repeatability. Included is an accessory port on the bottom of the PreciseLOOP HG-1 case. Each component is HIPOT tested to ensure you get constant and reliable performance.
|SWR/RL||14 MHz: 1.01 / 41.09 dB,
29 MHz: 1.14 / 23.40 dB
|LOOP CURRENT||14 MHz @ 10 W: 3.0 A.
29 MHz @ 10 W: 2.8 A
|BW (2.5 SWR)||14 MHz: 43.1 kHz,
29 MH: 321 kHz
|RADIATION CURRENT||14 MHz @ 10 W: 1.11 A,
29 MHz @ 10 W: 2.46 A;
|IMPEDANCE||14 MHz: 59.17 Ω,
29 MHz: 56.85 Ω
|LOSS CURRENT||14 MHz @ 10 W: 1.89 A,
29 MHz @ 10 W: 330 mA;
|INDUCTION LOOP||Copper tube 26”
|POWER RADIATION||14 MHz @ 10 W: 3.70 W,
29 MHz @ 10 W: 8.8 W;
|RADIATION LOOP||Low loss LMR 400 120”||EFFICIENCY %||14 MHz @ 10 W – 37% -4.3 dB
29 MHz @ 10 W – 88% -.5 dB
|SURFACE AREA||75.0 sq. in||GAIN||14 MHz @ 10 W: 1.5dBi (3-7 *dBd), 29 MHz @ 10 W: 1.5dBi (3-7 *dBd) * versus Dipole at 12’|
|TUNING CAPACITOR||Air variable dual stator||MAX POWER||45W PEP (SSB)|
|TUNING METHOD||6:1 calibrated dial||Mast||3 feet 6” PVC 1” diameter|
|QUALITY FACTOR (Q)||14 MHz: 339,
29 MHz: 90.4
|Weight with bag||4 lb.; Included items: 10′ Radiator, Induction Loop, tuner, Bag|
|RADIATION RESISTANCE (Rrad)||14 MHz @ 10 W: .074 Ω,
29 MHz @ 10 W: 1.36 Ω
|Speciﬁcations based actual measurements and/or computer models. All products are calibrated and tested to meet or exceed published speciﬁcations. PreciseRF warrants its products to be free from defects in material and workmanship for one (1) year from the date of purchase. If you need support or service for your PreciseRF product, whether the product is under warranty or otherwise, please contact PreciseRF and arrange for a return or repair authorization. Manufacture’s Suggested Retail Price (MSRP). Prices and speciﬁcations subject to change without notice. (c) 2018 all rights reserved preciseRF|
Speciﬁcations based actual measurements and/or computer models. All products are calibrated and tested to meet or exceed published speciﬁcations. PreciseRF warrants its products to be free from defects in material and workmanship for one (1) year from the date of purchase. If you need support or service for your PreciseRF product, whether the product is under warranty or otherwise, please contact PreciseRF and arrange for a return or repair authorization. Manufacture’s Suggested Retail Price (MSRP). Prices and speciﬁcations subject to change without notice. (c) 2018 all rights reserved preciseRF
Warren, KC9IL –
A well-built antenna, effective, and a delight to use.
I operate quite a bit of portable HF with my Elecraft KX-3. I already have the Super Antenna and a home brew 53 foot end fed with a 9:1 Unun. Both of these are good, workable antennas. However, there are times when I don’t have the time to set up either of these antennas, don’t want to have wires around where people can walk into them or trip on them, or when there aren’t any trees around. I have read a lot recently and seen demonstrations of magnetic loop antennas, so I started to investigate them. I had narrowed it down to the PreciseRF loops and the AlexLoop. I had a number of questions, and both Alex (PY1AHD) and Roger (W1RMS) were very helpful and responsive to my queries. Hats off to both of them!
My plans were to operate fixed portable (sitting at a table) as opposed to pedestrian portable (walking around). This had me leaning towards the PreciseRF offerings. I initially was looking at the Deluxe model, but already had a few tripods lying around, as well as a number of laptop computer bags, so I skipped the deluxe package with the small tripod and the deluxe carrying case. And I saved about $150 in the process by purchasing the Express package for $299. I did pick up the tripod adapter for $20 and made my own 12 foot cable.
The antenna arrived almost a week ahead of schedule. I had it assembled and on the air on my driveway in less than 10 minutes. Now I can deploy it in two minutes since I leave it assembled.
The entire antenna is nicely manufactured and has a good quality feel. The tuner is very smooth with its 6:1 Vernier dial. I can almost always get the SWR under 2:1 just by listening to band noise. It is a quick adjustment to hit the Tune button and get it down the rest of the way to 1.5:1 or less. The tuner covers from 40 meters all the way to the CW portion of 10 meters. The tuner box hits the wall around 28.300, above which the SWR starts to rise, but is still usable for most of the band, perhaps with the exception of the repeater part of the band.
I have done a number of on-the-air A-B comparisons between the PreciseLOOP and the Super Antenna and the End fed and have found the following:
1)The Loop is pretty comparable to the Super Antenna on all bands (40-10). Sometimes it’s an S-unit or so better, sometimes less. I attribute the parity on 40 meters to the fact that the Super Antenna is so physically short on 7 MHz.
2)The Loop is also pretty comparable to the 53 foot End fed (up in a tree) on all bands except 40 meters. Since the Loop is so physically small on 7 MHz, I’m not surprised that it can’t quite keep up with a 53 foot piece of wire. Nonetheless, it still performs quite well on 40, especially given how it improves the S/N ratio. It is still a very workable antenna on 40 meters.
All in all, I give the PreciseLoop a two thumbs review. A great performer and value.