| KC0PUZ |
Rating:  |
2014-06-12 | |
| RF burns and light construction |
Time Owned: 3 to 6 months. |
The AlexLoop provides good signal reports and as the Rating category of "2" on eHam states the Alex Loop "Needs help". The first step in tuning this loop is to listen for the loudest RF from the audio. To attain the lowest SWR, you must transmit and turn the knob at the high voltage point on this antenna. I've been watching a friend use this antenna since Christmas, and while observing him tune the loop while transmitting with minimal power, he received RF burns on two different occasions.
Did you see that metal shaft coming directly out of the center and connecting with metal gears to the knob you grab hold of, which by the way has a metal tap screw that carries the power that will give an RF Burn? The more I look at this image, I then realize the variable air capacitor is ganged in series. Does this lower the efficiency of the variable air capacitor? Also, see that little metal bracket in the bottom left side of the matching box in the shape of a C? That comes from the ground side of the capacitor, which then encompasses the shaft. Does this couple the inductance of the capacitor?
Then I realized that the Alex Loop doesn't even bond the feed points of their antenna to the outer shield of the antenna! What in the world is going in here? Only the inner coax and not the coaxial braid is being used for the actual physical connection of the loop? Surely this can't be! Does this mean the wire used as the active element is shielded from performing as well as many of the competitors whose active tuning elements are fully exposed (ref. MFJ Loop and the Alpha Loop)?
Just saying, the Alex Loop seems to work, but everyone should be aware of any products short-comings before buying it. So, while I'm on this subject...the Alex Loop uses a very cheap black plastic box where the MFJ plastic is a little better, though the Alpha Loop plastic is an outdoor UL rated high voltage enclosure.
As far as RF burns coming from the MFJ loop, you remote tune it, so it ain't going to happen. The closest thing to the AlexLoop seems to be the Alpha Loop and they use a nylon shaft between the knob you touch and their capacitor. Also, both MFJ and Alpha seem to agree that a single variable air capacitor that isn't ganged in series is the proper physical design. |
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| KD8OPI |
Rating: |
2014-05-18 | |
| Its awesome. Believe it! |
Time Owned: 0 to 3 months. |
It looks like it can't work. Its isn't big, there aren't any coils, it doesn't weigh much, there isn't a fancy website, a 300 page book on how to use it, or hundreds of dollars of accessories. You don't put it up very high, there aren't any guy wires, and there is no microchip. The man who builds it doesn't have a team of people with him at Hamvention; just someone who appears to be his wife. He doesn't even have his own booth. What he does have though, is a write up in QST and 49 reviews on this site that say his antenna is great. Make that 50 now.
I bought this gem at Hamvention 2014 two days ago and put it up this evening after it stopped raining for the first time in 5 days here in Dayton. I spent a whopping $2.50 or so in materials to build the AD5X camera tripod mount (its functional). I take the AlexLoop on my deck, it takes <5 minutes to assemble and stick it on the tripod its about 4 feet off the deck, 8 feet off the ground.
Moment of truth. I turn on the 817nd, and tune the antenna. Nothing to it. Peak the receive, fine tune the SWR on xmit (I get no SWR on the "meter" on the 817), it takes 30 seconds with about 20 khz of bandwidth around the tuned frequency with no readable SWR.
Boom. Here come the signals. I can spin the mount easily with one hand from my lounge chair. Ah direction! I hear a Puerto Rician station starting to call CQ on 15 M SSB. I spin the plane of the loop SE/NW. I answer. QSO made, 5/3 me, 5/5 him. Yup, almost 2000 miles, my first contact with the AlexLoop. I tune up, hear a Japan station coming in nicely. I answer, no QSO - but hey come on there's only so much 5 watts and a loop can do! I mosey down to 20M and break through two odd pile ups in Mississippi and and in South Dakota. I pack it in, Game of Thrones is coming on, but I'm in awe of this marvel.
I own the Buddipole, and I have an S9 31' vertical with 32 radials, and I have an Alpha-Delta 5 band fan dipole. The AlexLoop is just easier, lighter, and dare I say better than all of these options I have from my deck when I want to play on the radio in the summertime.
Comparison to the Buddipole is most appropriate. The Buddipole does not suck , it is a solid antenna. But, its shortcomings are that it is much more difficult to set up and tune than the AlexLoop, with similar results at QRP power levels. I gave up tuning the Buddipole a long time ago with the coils, and used a tuner with it. I've also spent a pretty penny replacing telescoping elements on the B-pole, because I had it up 15 feet and it fell or my guy wire didnt got pulled out of the ground. When would I use the Buddipole now that I have the AlexLoop? If I ever go on a DX pedition, and have a day to set up guy a tripod mast and want to run >20 watts. Or if I want to build the 10M 2 element Yagi. I won't use it for QRP fun, there is no need. Forget about a Buddystick config or my S9 31' vertical, the AlexLoop has them beat - you cant beat the ability to peak and null with the direction the AlexLoop gives you compared with verticals.
Listen, if you want to have fun with a small, directional, effective antenna that is a snap to tune which you can mount on a simple camera tripod get this one. It really works, and works very well. Looks can be deceiving.
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| PA3CWQ |
Rating: |
2014-05-17 | |
| 5/5 |
Time Owned: 6 to 12 months. |
| It gives me a lot of fun working QRP in digital mode like JT65HF during my Holiday’s and also from my QTH of course. In May I was in Spain near Moraira Costa Blanca in JM08BR. I am always traveling with my qrp-rig, the Yeasu FT-817 (with a little accu) and my Alex loop. This loop gives me a lot of fun, only a little bag in my suitcase and I am qrv from 10 to 40 meter. I was calling cq on 14.076 MHz with 5 watt and John VK7XX was coming back for me. That gives me a lot of fun. |
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| AD0DQ |
Rating: |
2014-05-15 | |
| Best Portable Antenna |
Time Owned: 6 to 12 months. |
| I bought this unit without recognizing that it has a 25 watt power output limitation. When I discovered I was limited to 25 watts out, I was really upset about that (but that was my fault, not AlexLoop). But we had a special event (W0O -- Frankenstein MO) and I took my Alex Loop and worked PSK from Frankenstein, MO. I set the unit out in the yard, ran 25 feet of RG58U to it, tuned it with an MFJ259, and went to work on 20 meters. I made dozens of contacts on 20 meters from Florida to Seattle with band conditions that were less than optimum. I did that on 25 watts, and felt like I had better performance from the loop than I would likely have had from a dipole or some other temporary or portable 20 meter antenna. I would recommend this antenna for anyone who needs a portable and functional QRP antenna, with the understanding that you need to stay below 25 watts. |
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| K7RNO |
Rating: |
2013-11-24 | |
| A gem of a portable antenna! |
Time Owned: 0 to 3 months. |
Below are tons of reviews with QSO reports, so I'll spare you with that.
What I feel the need to address are these points:
1. Even if your rig has an ATU built in, resist the temptation to use it. You would do yourself a disservice. Your ATU will not and cannot tune the actual loop. You must tune the loop with its integrated tuner or you will leave power on the table! I put my ATU on bypass.
2. To get a solid mount, you want to have a base with the proper outer diameter to JUST fit inside the black pipe. The super lightweight (i.e., super flimsy!) Vivitar tripod's center column is too thin and needs an adapter that you can build with something in your junk box. Be creative, and duct tape is only one solution.
For better support, consider a heavier (i.e., more stable) tripod with a thicker column that might just fit out of the box. But for hiking, that light Vivitar thingie is hard to beat.
3. To speed up tuning from band to band even more, I use a modified knob with a 360° scale, which I calibrated to know the values for the individual bands. In my case, particularly the 17m sweet spot is often nearly impossible to hear, so calibration helps a lot. I posted an image here:
http://groups.yahoo.com/neo/groups/KX3/photos/albums/292559262/lightbox/173537466
The +/- column on my labels shows the bandwidth in kHz above and below the tuned f that I found doesn’t require retuning.
4. Follow Alex's recommendation to fine-tune the loop with just your fingertips. This way you avoid your fingers influencing the capacitor and detuning it some when you withdraw your hand.
5. This antenna is a blast! There will always be more efficient and less compromised ones, but none of those are as quickly set up and as versatile. Well done, Alex!
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| ON6KE |
Rating: |
2013-11-22 | |
| I must be MAD! |
Time Owned: 0 to 3 months. |
Hi everyone,
I must be MAD, totally bunkers, gaga, I ordered a Walkham loop this morning, 385 US$ shipping included, PLUS 21% if Belgian customs sees fit to add tax to it!
I sure hope the loop works extremely well.
By the way did anyone notice that there are 2 language errors on the English version of the tuning unit?
'recIEve' and 'trasmit'. |
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| KJ4FUU |
Rating: |
2013-11-13 | |
| Works even better than expected |
Time Owned: 0 to 3 months. |
This antenna is easy to set up and take down, and gives me a little bit of directional capability also. I've taken it out to the back yard for a couple of weekends, and had some success reaching some state QSO parties and special event stations.
My first time out the takedown speed became a major plus, because it started to rain. I quickly disconnected the radio and put it in the waterproof box. The Alexloop easily came down within 5 minutes, giving me time to haul everything inside before it started pouring down hard.
Tuning, even without an antenna analyzer, is simple.
I would recommend the Alexloop to anyone who likes to operate portable, or is restricted by the HOA from putting up a full-sized antenna. |
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| WW4MSK |
Rating: |
2013-11-06 | |
| Great QRP portable antenna |
Time Owned: 0 to 3 months. |
I've been using with decent success end fed wire antennas for portable and maritime mobile QRP with my KX3. In my search for another type of antenna to use, I came across various YouTube videos of people using magnetic loop antennas. It seemed to fit what I needed, something lightweight, easy to deploy/takedown and work on most bands I use.
From order to delivery took a little more than a week from Brazil to the USA. Alex provided a tracking number and once clearing US customs arrived nicely packaged. I had my radio ready to go on the deck outside, and from unboxing to first contact was less than 5 minutes. Not bad for being completely unfamiliar with the antenna, and I now could have it set up within a minute or two.
First contacts were from Georgia to the midwest on 20 meters, psk31 and 5 watts. Good signal reports were received and I then hunted for some DX. Reached Venezuela, Brazil and the Canary Islands quickly. I did not have much time to work it more, and plans are to find out what it can do in a true portable situation.
In closing, I was skeptical at first and put quite a bit of faith in the number of great reviews for the AlexLoop. Early in the use of the antenna I have found all prior reviews to be accurate description of the performance of this antenna. I'll do a follow-up review in 6 months as that should be enough time for more portable & maritime mobile operations. |
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| EA3HSO |
Rating: |
2013-10-28 | |
| Big antenna performance! |
Time Owned: 0 to 3 months. |
Bought mine about a month ago and didn't have time to go out and test it.
So yesterday, at the end on the WW CQ contest, I set up on my deck with FT817nd with internal batteries (2.5w) and the Alex Loop.
In an hour full of strong signal pileups I managed to work 2 us stations (W4RM - 6533.6 km, KA2EYH - 4399.8) and stations from the Canary Islands, Latvia, Cyprus, Romania and Bulgaria.
All in the middle of a lot of screaming big signals.
Directivity is not brutal but enough to feel some gain difference.
Tuner circuit works great and is really easy to get used to.
Tuning is really sharp, but after some use it's easy to find the sweet spot by ear.
Sets up in 30 seconds, stores in about the same time.
Still need to do some testing in the mountains, but its performance in the middle of urban Barcelona blew my mind.
And without the hassle of radials...
I thing my other portable antennas are going to see some dust. In the closet!
73. |
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| N0BOF |
Rating: |
2013-10-27 | |
| Simply Amazing! |
Time Owned: 0 to 3 months. |
I'm usually not a contest participant but I chose the CQ World Wide DX SSB contest to check out the Alexloop. This was the first time I had it out of the nicely made case. The setup took about 5 minutes and I was hooked up to my KX3. Tuning was as simple as turning a knob and listening. With no more than 5 watts of power, I made contacts with dozens of stateside stations (including Alaska & Hi)and the following DX....Aland Islands, Poland, Ukraine, Russia, Germany, Estonia, Scotland, Canada, Azores, Latvia.
This was all done sitting in a recliner, with the Alexloop next to me on a tripod, in my daughters first floor apt surrounded by numerous commercial buildings. All I can say is yes, this thing works as advertised! I think I found my new SOTA antenna. |
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