| K5KWG |
Rating:  |
2017-09-28 | |
| Best mag loop and easy to tune |
Time Owned: 0 to 3 months. |
Been a ham 56 years. Used lots of xmit and receive loops. This is by far the best. Easy to tune to 1:1 and it works. I run 5 watts from an 817 and most of my cw and digi calls are answered even at 5 watts. The remote tuner version is a must. Band or frequency moves in less than a minute. Stores in a 16 x 16 x 4 box and assembles in 3 minutes. For portable qrp ops this will be very hard to beat. I use a speaker tripod and the unit bolts to the quick platform that came with it in seconds , no holes to drill.
One of my best purchases in ham radio. |
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| K5ACL |
Rating: |
2017-05-31 | |
| Great loop antenna |
Time Owned: 0 to 3 months. |
This is my second mag loop antenna. I primarily operate SSB & digital modes. The W4OP loop has been my primary 'testing' antenna so to speak, due to its easy deployment, and excellent QRM rejection broadside the antenna. There's just something about being able to setup an antenna on a table top that's extremely convenient! That's where an antenna like this shines - rapid deployments so you can get on the air in a jiffy!
I'm able to fine tune this loop better than I was able to fine tune my other mag loop from a different vendor. They both use a 6:1 reduction drive - but the tuning on this thing is very finicky - almost so much that just applying simple pressure on the dial changes the SWR (I find this to be true on just about all of the bands, more so on the lower - though a high Q is always good). The coupling loop is adjustable which is probably the biggest advantage with this loop, since efficiency is absolutely critical on a loop.
My SWR curves are much sharper on the W4OP vs my previous loop, in some cases I've almost been able to achieve a perfect match on 20m and up, depending on how much I want to fiddle with the antenna. I haven't noticed as much of a capacitive effect while tuning with my hand with the W4OP loop that I did with my previous as some other users have mentioned, which definitely helps with tuning.
Parking on one frequency with this thing is ideal - I can't imagine trying to band hop, or search and pounce with this loop. I also found that the frequency indicator marks on the front aren't exactly in line with where I'm at, but that's no biggie at all, it gets me in the general area, I use noise level to rough tune, then an analyzer to fine tune (if needed).
My only gripes with the loop are that I wish it were a bit sturdier. I'm fearful of placing the coupling loop inside my bagpack because it's very easy to bend, so I'm not sure how this loop would hold up to the rigors of serious field use, but with my type of operating, it was a perfect balance between quality, efficieny & cost. The heliax is a nice addition and helps to keep the loops shape, but I've found that it's not the most portable, I may try to self solder a piece of LMR 400 for portable use. I also would have liked for holes on the tripod adapter plate so that you don't have to remove the tripod adapter plate to place the feet back on the antenna (would also provide additional protection for the antenna by allowing the metal plate to stay on the bottom at all times).
Could I notice the efficiency bump on this loop vs my previous? A tad... Is that a correct technical ham term, a tad? lol. Signals sounded a bit louder, and my received & sent digital reports were a bit better on this loop than my previous.
Pricey? Yes... maybe a tad cheaper than others currently - All in all a great product. I'm a ham with only a few years experience, and I've tried DIY loops, but nothing that would ever be as portable, durable or as efficient as this guy. |
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| NM8R |
Rating: |
2017-04-08 | |
| Efficient, Small Footprint, Rapid Deployment |
Time Owned: 6 to 12 months. |
My W4OP loop has opened up an entirely new world of QRP portable operation. For efficient, small footprint, rapid deployment use it is the ticket.
Mine replaced a 31' telescoping pole vertical w/TV tripod, radials and loading coil, that I made up for NPOTA use. That setup performed well, but was not exactly portable - it required my Jeep to get it to the site. It was a chore to deploy in every aspect.
By contrast, the W4OP loop breaks down & rolls up compactly enough, that in combination with my FT-817, my wife and I can backpack it in on our fat bikes along the North Country Trail. Setup of the entire station is fast.
The support solution is easy: I use a medium duty air cushion 'light tripod' that was $32 on Amazon. It supports the loop well, and is small enough that it can be strapped to my backpack.
This loop also has much lower profile than some verticals. That may matter to some users.
The tuning is very sharp thus the vernier drive is handy. Learn to read the dial markings to get in the ballpark. The reason for the razor sharp peak is the Q of the loop is very high. (That is a good thing. A loop that peaks broadly is lossy.) Someday I will put it on my VNA to measure it.
A word about tuning - I taught my beautiful assistant, N8HGM, to tune by ear. She can scoot in and peak the tuning, then scurry her little self out in no time. For safety don't transmit, even at QRP levels, while someone is close to the loop.
It's well made. The ex-engineer in me forced me to open the tuning box to scope things out. Nothing made me wince - construction very much met my approval.
We also highly recommend Helinox camp chairs. Compact, easy to pack in, comfy.
Scott
NM8R |
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| KD5KC |
Rating: |
2017-01-08 | |
| Used many Mag-Loops, this one is the best yet! |
Time Owned: 6 to 12 months. |
Right from the start, let's be clear about this. A Magnetic Loop Antenna is not going to equal a dipole hung a half-wave above ground or a good Yagi or Quad on a tower. However, you aren't likely to get a Yagi or Quad and a tower portable, and even getting a dipole up 1/2-wavelength isn't always possible.
Also - I am not employed by any loop manufacturer, nor do I make any kind of profit on the sale of any mag-loop product in any way. I have become friendly with a couple of loop manufacturers over time, and likely I am equally hated by a few others. I am no scientist, I do not have a bench full of test equipment. But I do have a log with thousands of contacts made while portable or Pedestrian Mobile. And I can tell quality from cheap junk. In a 60 month period I was atop 120 different summits operating portable, that's 2 summits a month. And have the log entries to prove it.
I have been operating Portable, Pedestrian Mobile and SOTA for about 7 years now, with thousands of QSOs in the log. I really value an antenna that covers as many bands as the radio has. I dislike being limited to 1 band or mode simply because that is all the antenna can handle. In all this time I have had the opportunity to use or operate alongside many different portable antennas. My favorite antenna for maximum portable efficiency is the 88' Cebik Doublet. If you want a good signal on many bands, this is it. I have successfully used the Cebik Doublet from 80m through 6m. However, it is time-consuming to set up, needs to be hung high, and needs a tuner. My next best choice would be an End Fed Half-Wave Antenna (EFHWA). I built one that covers 40m-30m-20m-17m-15m, this was accomplished by connecting or disconnecting various wire segments for each band. It too has good efficiency, but also has the disadvantage of needing to be hung high and needing a tuner. Where I live, trees are not available much, and are usually the stunted desert shrubs. Carrying around a Jackite-Pole or other mast just makes more weight and more work. I have done it, but it usually needs a helper and guys to keep it up. On high summits, you want to set up and pack out quick, especially if clouds begin to form.
I have either owned or borrowed just about every reasonable portable antenna you can imagine. The Yaesu ATAS-25 and Icom AH-703 portable antennas are cute, but not very efficient. The Super Antennas MP1 is a little better but still in the cute category. Perhaps the best of the verticals is the Buddi-Pole. I have tried them all at one point or another. In fact I can see my Buddi-Pole is still here, on the shelf in the black carry-bag, covered in Dust. I guess I should sell it if it is collecting dust. I eventually built my own Pedestrian Mobile antenna to cover 40m - 6m. All the verticals suffered from two problems for me. #1 - they were very finicky to tune, requiring a lot of time (15 minutes is a lot of time on a summit), and they needed radials that always seemed to be underfoot and getting tangled. I thought all of this was just part of being an efficient portable station, and I suffered along with the various difficulties for a long time.
In the spring of 2011 I was planning my usual trip to Germany, and I was discussing my antenna options with other local hams on 80m. I wanted to keep it light-weight, small, easy to set up, and not something difficult to transport on an airliner. Someone had an Alex-Loop for sale, and he sent it to me for a trial run. My first thought was "Snake Oil". But in just a few contacts made on 40m and 20m I sent him the money. I was convinced. Weight was under 3 pounds, it fit in my backpack, and I could go from dropping the pack on the ground to calling CQ in under 5 minutes. Best of all, it worked 40m through 10m. It wasn't as efficient as the Cebik Doublet or the EFHWA, but over time it has proven to be equal to or better than the many verticals in efficiency, and certainly easier to set up and tune. I typically have 5 to 15 QSOs in the log before my friends with verticals are tuned and ready to go. And switching bands is a 15 second operation on the loop, not so easy on the verticals.
Since 2012 I have had the opportunity to use myself or to operate beside a number of other antennas. In September of 2014 I had the opportunity to activate a summit with another ham who didn't want to pay the price for the Alex-Loop. He got the Alpha-Loop because it was cheaper. This was the model with the 8-segment aluminum loop that you had to assemble with screws and nuts. The comparison wasn't pretty. The Alpha-Loop assembly was time consuming, and the Alpha-Loop was 1 to 2 S-units below the Alex-Loop on both transmit and receive. Because of the way the loop was designed, the SWR was not stable, constantly jumping from 1:1 to 2:1 when the wind blew. And speaking of wind, the Alpha-Loop blew over twice. The second time it blew over it was badly damaged and AFAIK has never been used since. The supplied tripod was insufficient for the antenna. He later bought an Alex-Loop.
Sometime later a visiting ham did a local summit with me. He had the Chameleon Antennas CHA loop. The results were about the same, the CHA-Loop was 1 to 2 S-units down from the Alex-Loop on both transmit and receive. In my opinion it was designed and built better than the Alpha-Loop, but it was at least 3 dB below the Alex-Loop, and not nearly as portable/backpack friendly. Reading the sales info of the CHA-Loop is amusing to comical. Any student of the mag-loop antenna can see through the claims and smile. And look up Aluminum Oxide (AL2O3). There is a really good reason for not making the main loop out of aluminum parts that you assemble and disassemble. You cannot prevent aluminum oxide except under water or in space, and it is not a good thing in a Mag-Loop antenna.
In late 2015 I was given another new Alpha-Loop. This was a new design, using coax for the loop. Then antenna was well thought out from the standpoint of fast assembly and dis-assembly. But it had a different problem. It was more or less permanently mounted to a little desk-top tripod. The places where I operate don't usually have a bench or table available, and the places that do are often aluminum picnic benches, not wood. Setting it on the ground was very inefficient. So this antenna was already not optimized for my uses. I played with it a few times, and I decided that it was slightly worse overall than the original Alpha-Loop design. After playing with it for several more weeks, I put it away. Since it was given to me, I eventually passed it on to a young boy who is interested in ham radio. He uses it as an RX antenna presently, but he is talking about getting his General license this summer. For a 10 year old on a budget, it is a good starter antenna. I expect he'll outgrow it quickly once he starts transmitting.
All of the above is useful background information. The point is that I have much ON-THE-AIR experience with a number of antennas.
Enter the W4OP-Loop antenna. I have run in to Dale-W4OP a few times. He was best known among the portable antennas for PAR End-Fedz antennas. I contacted him a few times discussing the 3-band model, it only worked 40m-20m-10m. I even asked him if there could perhaps be a 60m-30m-15m version built. My portable radios are all capable of at least 40m through 15m, and some 160m through 6m or more. I was not satisfied with the limited bands, and the answers Dale provided caused me to search for other products. By all accounts the End-Fedz work very well. But they didn't meet my needs. Dale also designed some special mobile antennas a few decades ago that I still gladly run on my jeep to this day. So when I learned W4OP was working on a mag-loop I was excited, and bought one of the first ones available.
When the W4OP-Loop arrived, I immediately unpacked it and gave it a really good look. The workmanship was impressive, and the attention to detail was quite visible. Some money could have been saved in various ways at the sacrifice of strength or efficiency. But those savings were ignored and the better parts were chosen over the cost savings. The first time I used the W4OP-Loop was in my back yard. I set the loop on top the dog house and connected my Yaesu FT-817ND to it. I found a guy calling CQ on 20m and I replied. I gave him a 5-9 or a little better, he gave me a 5-7 with light QSB. I was impressed. We chatted for a while, I didn't mention QRP-portable until he asked. When I told him I was standing in my backyard with a 5-watt SSB radio hung around my neck and a portable loop antenna on top the dog house, he didn't believe it. I got my wife to snap a photo with my cell and I E-mailed it to him. WOW!
Over the next several months I used the W4OP loop in several operations. In particular I participated in several NPOTA operations using it, with several hundred QSOs logged total. I have used it on all bands 40m through 10m. I have as of writing this not tried it on 60m. In October an opportunity to operate SOTA in a new state came up. It was a very cool and wet operation on Pilot Knob in SW Missouri. The antenna performed very well even in the rain with a few dozen QSOs logged in an hour. However, while packing it up to hike down the summit, I somehow broke the antenna. IT WAS MY FAULT. When I got back to the motel, I E-mailed W4OP and explained what I broke. His reply was simple. Send it, we'll fix it. So when I arrived home I mailed it off. I had to leave for Germany a week later, and wished I had it for the trip to Europe. I had to settle for the Alex-Loop. When I arrived back home, I found that Dale had not only fixed what I broke, but he applied all the upgrades to the antenna to bring it up to the latest version. All at no cost to me. I have since used the antenna in several more operations, and it has performed flawlessly. One of the upgrades made it even more portable, making the supporting mast from three shorter segments rather than two long ones that stuck out of my backpack.
I would highly recommend the W4OP-Loop for anyone living in an antenna-restricted situation. In the yard, on a balcony, or even in the house by a window, it will almost certainly out-perform a random wire below the roof-line. And the loop has other properties valuable to the indoor operator, like broadband noise rejection due to the hi-Q of the tuned circuit. Wrap the main loop in pretty plastic flowers in the spring and summer, in fall-colored plastic leaves in the fall, and in plastic pine branches for winter, and call it a seasonal home decoration. No one would ever suspect it was a HAM RADIO ANTENNA!
The bottom line is this. If I have a significant hike and climb coming, I may decide to use the Alex-Loop for its smaller size, lighter weight and better packing. But if I can see my way beyond the extra weight and size, I will take the W4OP-Loop because it is by far the more efficient antenna. If something happened to my W4OP-Loop today, I would certainly buy another ASAP. It is currently my #1 portable antenna.
Vy73 -- Mike -- KD5KC.
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| K2WO |
Rating: |
2016-11-16 | |
| This is The One! |
Time Owned: 0 to 3 months. |
OK, portable loop antennas like this are not the best antennas for portable operation, but they definitely serve their purpose when you need to set up quickly and when other better antenna options are not available. I have owned the AlexLoop, the Alpha Loop and now have the PAR W4OP Loop antenna. Both the AlexLoop and the Alpha Loop antennas are decent performers and work OK. The AlexLoop is especially nice because of the carrying case and the versatile design. Out of the case, you still need to come up with a way to mount it. As provided, no tripod or mount is provided. The Alpha Loop does come with a tripod and case which makes it easy to set up and put on a table. Both the AlexLoop and the Alpha Loop perform OK on 20 through 10 Meters. Tuning with the Alpha Loop is a little easier than the AlexLoop, but this is not a game changer.
Now, let's take a look at the PAR Loop. The main loop is made of LMR-400, which is not as flexible as the others, but provides for better efficiency (which is a godsend in one of these miniature antennas). The smaller loop is made of brass and has a matching network (mine is not potted, but I understand the latest version is. I may look into that). It also is attached to the mast with a clamp that allows it to move up/down, also providing for greater efficiency. The matching network, with variable capacitor has a 6:1 Vernier drive, which allows for very precise tuning. It also comes with a 2 piece mast (I understand it is now 3 piece) and 4 "feet" that allow for easily placing the antenna on a table. A spring-loaded clamp is also provided for clamping to an available post, table, etc. I purchased the optional Tripod mount, which allows the antenna to be easily mounted to any photo tripod (GREAT!). Quality of all materials is top notch. All built to the high standards of all PAR products (I own several). Performance on 10-20 meters is great and slight ly better on 20 in my opinion when compared to the competition. On 40 and 30 Meters, in my opinion, the PAR stands head and shoulders above the competitors. The PAR also has provision to operate on 60 Meters, although I haven't tried it there. For traveling, I found a large bag at a local surplus store that fits the PAR loop perfectly.
I have been very pleased with the PAR Loop and I can recommend it strongly. It is American made and the owner/engineer/designer, Dale Parfitt, stands behind his products. He knows what he is doing and there is sound engineering in all of his antennas. Oh, and did I mention that his pricing is VERY competitive when compared to the other antennas mentioned? |
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| W7BV |
Rating: |
2016-10-03 | |
| Update - new modifications |
Time Owned: 3 to 6 months. |
This is an update to my initial review (August 9, 2016) of the Par Electronics W4OP Magnetic Loop. Since then, Dale has provided me with updates mentioned in my initial review – a three piece mast that now screws into the top of the tuning box and a stiffer coupling loop together with a potted matching circuit board. Together these modifications have significantly improved the portability as well as durability of the original W4OP mag loop. As indicated previously, “on the air” performance has been excellent with higher efficiencies than other currently available coax loop antennas having smaller loops. It should be noted that production of the W4OP Loop now has been assumed by LNR Precision. It is my understanding that the modifications mentioned in this review will be incorporated in the current production run. A 6 meter option also will be available.
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Earlier 5-star review posted by W7BV on 2016-08-09
The PAR Electronics W4OP Magnetic Loop made its debut in Dayton in May at the LNR Booth and currently is advertised on the PAR Electronics web site. I fully agree with the review by K3OQ that it is well made, as well as easy to assemble and tune. It has a number of design features that set it aside from other commercially available loops. First, the loop is 47” in diameter and made from Andrews 3/8” flexible heliax coax resulting in higher efficiency especially on 30 and 40 meters and better retention of shape when deployed. Yet, it still rolls up into a 14” coil for storage and transport. Second, the coupling loop is a hybrid design with a matching network and is adjustable in its relation to the main loop to minimize SWR. Four stabilizing feet are provided which can be attached to the tuning box to enhance stability when set on a table. A large, strong plastic clamp also is provide to permit clamping of the tuning box to a table or a porch railing. An optional tripod adaptor that attaches to the bottom of the tuning box also is available. All of these supports have been tried here and work very well. During the past weekend, a number of CW QSOs on 20 and 40 meters were made using this antenna sitting on a table on my back porch and fed with 5-10 watts from by KX2 xcvr. Even with poor band conditions QSOs from Tucson, AZ were easily made with Hawaii, South America, and the East Coast. “On the air” performance was excellent. Initially, the antenna was meant for backyard or park operation where waterproofing and smaller footprint were not a concern. However, for many of us, there is need for a few improvements to enhance set-up and portability. First, the loop support mast should be made with three pieces of ½” aluminum tube rather than two to reduce storage length. Second, the mast should have a ¼”-20 stud and attach to a female socket on the tuning box for ease of “take down “ and storage. Currently, the mast is attached to the top of the tuning box by a ¼”-20 screw that is passed through the box lid which requires opening the lid of the box. I added a nut to the outside of the box so as to easily remove the mast but that leaves the screw sticking up and needing to be covered with a plastic or rubber cap to avoid damage to surrounding objects/persons while in storage/transport. Finally, the matching circuit board on the coupling loop should be “potted” or somehow made weather resistant. Dale tells me all of the above mast modifications are in the works and how to weatherproof of the matching network is being evaluated. In short, the new W4OP Loop Antenna is a great one!
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| KB2NAT |
Rating: |
2016-08-30 | |
| No Gimmicks or surprises |
Time Owned: 0 to 3 months. |
I’ve had my W4OP mag loop for nearly two weeks now, enough time to give an initial (and first) review. To be fair, I’ve only been able to use the loop inside and I’ve compared it with a Miracle Whip Antenna and my 135’ semi-NVIS antenna that is stealthily stuck in some trees away from view and RF interference.
Our house is gravid with RF. Sources include the electric stove & washer/dryer that turns the entire wiring system into a hash house of ECM. That is a caveat for many of us. The mag loop, however, hasn’t been that effective vs. the noise but I also don't currently have the option of being able to null out band noise..
I researched mag loops for several months. I checked everything from the $1500 loop that looked like a submarine/tank part to the MFJ loops. Some were absurdly costly and the MFJ tends to arrive in kit form and I’m not into rebuilding and they didn’t respond to my email. The only thing I needed to do with the W4OP loop was to adjust the support holder that supports the top of the loop, It is held by two small loop ties and is supposed to be in the loop’s mid point. Mine wasn’t. 2-3 minutes if furious work corrected the problem by simply twisting and sliding the ties over.
The only other loop in its class might be the Chameleon F loop Plus. They seem to be a good company with a good product. But the W4OP loop is larger and more efficient, though how much of that is audible is another question. It looks impressively enormous sitting on a desk top, though.
Dale Parfitt, the designer of the loop, answered my questions and took time to explain things before I bought the loop which is a always a plus. LNR Precision is now the company who is responsible for producing them.
When my loop survived arrived (USPS stands for “Unusually Slow Partial Post)”) it was well packed in an 18”X4” box. Everything was in protective padding. Five minutes put it together. The feeder loop was bent (easily straightened—hmm?), and Dale told me that a stronger feeder loop was being designed for protection from heavy-handed hams. He should have mentioned the USPS.
The main loop is about 44-45” (not 47” as you might read on line—no biggie) and everything looked good and well thought out. The tuning knob operates a front vernier dial and is very easy to tune. There is no capacitance effect. Once adjusted, it doesn’t change when I remove my hand.
Also in the offing is a decal for the front to help rough tuning, but I made my own. Tuning is easier than I thought. Yes, tuning is very sharp on the lower freqs and that’s good because, unlike Star Trek, I want all the Q I can get. Still, though, tuning down there is easy. A very low SWR is obtainable by removing surrounding antennas, metal statues, etc. and ensuring that the feeder loop is very close to the main loop.
It is sensitive to surroundings On 40 meters, there’s too much RF to really take advantage of the loops qualities although I can adjust its angularity for minimum noise. Still, it’s not comparable to the outside antenna. At 20 meters, things improve dramatically where it’s only a few s-units below. Obviously, the M-Whip is significantly below the performance of the other antennas.
Interestingly, sitting on my desk, the loop hears minimally through the noise on 40 meters, yet oddly enough, I could hit Florida SSB the other evening on 40 meters with 15 watts…not great, but it was there. It transmits surprisingly well. I will be going through the circuit breakers soon to isolate the issues (I may end up working on battery power) of RF noise.
I give this a 5 because it is all that it is supposed to be. When we move into a condo, it will hopefully have to deal with less full-spectrum noise transmissions and be more effective in a lanai, and I should have the ability to use its ability to null some RF out.
The pros: transmits well, becomes very competitive with exterior antennas at higher frequencies, is well made and easy to tune, transports easily and is well priced, very efficient.
The cons: a receptacle for a camera tripod would be a nice addition to be built into the bottom of the unit, somewhat low power rating (15w SSB/CW)—I would have paid more for a more rugged capacitor. |
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| K3OQ |
Rating: |
2016-07-16 | |
| Absolute joy to use |
Time Owned: 0 to 3 months. |
After being happy with and using an Alpha loop for several months, I heard that W4OP was produce a similar product. I was one of the first to purchase one, and I have to admit that while I was very happy with the Alpha Loop, I am even more happy with this antenna. To me, using hardline for the larger loop made it easier to assemble, and the veneer tuning made it much easier to tune.
I used this antenna running QRP for an hour or so in the RAC contest, using a Flex-1500 and it felt as though I was running more power. If I heard a station, I could work the station. During the IARU contest, I had 3 or so hours to spare, so I drug out the LNR Precision LD-5 and hooked it up to the W4OP Loop. For QRP levels worked just under 30 QSO's and this time had some DX QSOs.
Since I have only had the Alpha and this Loop, comparing the two is fairly easy. I found that I could tune the W4OP Loop easier and quicker when I needed to change bands or QSY to another part of the band. I may be wrong, but I seem to have bee heard a little better on the W4OP loop than the Alpha.
If fact I am getting currently preparing to participate in the NAQP RTTY Contest using the loop and the LD-5. So hope to see folks on the bands later today.
I highly recommend this antenna for anyone who is like me, in antenna restricted communities. So long as you manage your expectations appropriately, I think this antenna will surprise you.
GL es 73,
Jeff (K3OQ) |
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