Sunday, April 21, 2013

The Alexloop vs my attic dipole

The new Alexloop antenna
Just over 2 weeks ago I placed an order for the Alexloop,  For some time I have been debating what antenna to use when I was out and about with my KX3. I looked at the Miracle whip, Par end fedz antennas and the Alexloop. For my needs it boiled down to the Alexloop. I did have a miracle whip in the past and it is a great antenna but just not worth the money for the performance you get. The Alexloop was ordered and arrived within a week and a half!! I was very impressed with the reviews online and the testimonials at Eham. . The antenna comes in a very well made carry case that can be taken into the field with all parts contained for your setup......well almost all parts...a tripod is one of the recommend ways to setup the antenna for field work. There are other ways it can be deployed including holding it by hand (not as young as I used to be so this method my not work for me). You can clamp it to a pic-nick table or attach it to a chair....just for starters.  The unit cost's 299.00 and I will say this is not cheap but it's very well made and portable as well. The case that holds the unit is about 1.5 by 1 foot in total. I also want to add that the case is very well made with a shoulder strap and carry handle.

A quality case

So lets get to the nuts and bolts.....how does it work....sure anyone can say anything about their antenna but the proof is in the radio waves!!
Antenna location..cat standing guard

I wanted to do a comparison between my attic dipole which is the Alpha Delta DX-EE up about 30 feet in the attic and the Alexloop set up in my XYL's office just opposite my radio room. Let me state that this is not a comparison to see which antenna preforms better as that is not a fair comparison....but I wanted to see how well the loop did compared to my attic dipole. The Alexloop was mounted on a tripod....well ty-wrapped to it as the the Alexloop would not fit over the tripod center pole section. This is something I will have to work out later. Each of these antennas have their disadvantages....the dipole is in the attic, this means a wooden roof above, rafters all over and insulation below. The Alexloop is in a second floor room, it's a small loop antenna and very close to the ceiling. So really both antenna are far from ideal when it comes to location.
Temp tripod mount
For the rig I used my Elecraft KX3 (as this is the rig I will be using when in the parks, backyard and where ever else I decide to go!) The power output was set to 5 watts and the bands I chose were 20m and 40m. The plan was to run coax from the Alexloop to a 2 position antenna switch and switch between the two antennas. The Alexloop did not seem to take a liking to the added coax. I was not able to get the SWR down below 2. Once I used the length of coax that came with the loop (about 10 feet) all was well. This just meant I was going to have to connect and disconnect the KX3 from one antenna to the other for the comparison. I was calling  CQ on 14.060 and 7.020 on the attic dipole and call CQ on 14.050 and 7.032 on the Alexloop and check out the Reverse beacon network to see who was picking up the CQ call. Not sure if the conditions were not all that great but both on 20m and 40m the attic dipole just got hits in the U.S as did the Alexloop. There was one big surprise when the Alexloop had a hit with OL5Q (along with the attic dipole) I was very impressed that a loop antenna in a bedroom was able to get a report from OL5Q!!
My overall impressions of the Alexloop are as follows:
1. Shipping was fantastic, this antenna got here from South America faster than products I have ordered from the U.S.
2. The support is great, I had a question about the loop when it arrived and it was answered within 30 minutes!!!!
3. This unit is quality quality quality from the carry case to antenna!!
4. The tuning was a cinch, turn for peak noise and then transmit and tune for lowest SWR....takes about 20 seconds!
14.060, 7.032 Alexloop
5. Assembly is done in 4 minutes for a first timer and I imagine with practice I can cut that time in half.
6. Antenna foot print is very low profile and can be used vertical or horizontal.
7. The SWR on 20m and 40m (only bands used so far) was 1.4 at 14.060 and 1.7 at 7.032.
The bottom line is I am very very impressed with this antenna and I will be taking it to the field and updating the blog on how it does.  Up to this point would I recommend this antenna.......dam right I would it's support is excellent, quality of the product is way above par and so far the results have been very impressive.
 

16 comments:

  1. Keep us " in the loop" ... so to speak...

    73bob

    ReplyDelete
    Replies
    1. Not to throw you a "loop" but you can count on it!!
      Mike

      Delete
  2. I'm thinking of the portable QRP version for a balcony , so will be interested in on-the-air results. 73 Dick

    ReplyDelete
    Replies
    1. Good afternoon Dick, so far the only testing that has been done up to this point is RBN test. Just today I looked at the bandwidth on each band as well and will be posting the results on the blog later today.
      Mike

      Delete
  3. Hello Mike, I think it's a lot of money for a loop you can probabely make yourself. Although quality is outstanding and there is a nice case with it. Not shure if the price is including the tripod? I would love to test such a loop. I hope you can make many contacts with it. 73, Bas

    ReplyDelete
    Replies
    1. Hello Bas, The price does not include the tripod I had to provide that myself.....but with my XYL being a photographer that was not a problem. Yes the price is up there but then again I was not keen on making one myself. What I have noticed is lots of things in this hobby can be pricey.
      Mike

      Delete
    2. Bas,

      You can buy the tripod for $10. I have an AlexLoop as well and it is a very impressive antenna and very portable. Also low profile for expeditions to city parks or mountain tops.

      72,

      Mike AD5A

      Delete
    3. Good evening Mike, thanks for the info. I am looking forward to getting out and about with the loop this summer.
      Mike

      Delete
  4. Hi Mike, I have watched the youtube videos about the Alexloop. Looks very nice. And when you don't jump up and down the band, tuning is no real problem. I am curious how you are doing with this loop. 73 Paul

    ReplyDelete
    Replies
    1. Hi Paul nice to hear from you....today I did some bandwidth tests with the loop and it's not to bad. I will be posting them on the blog I hope today sometime.
      Mike

      Delete
  5. Mike, nice comparison of your antennas. I tried to compare the snr of the rbn and had the impression that the loop was always several db below. Is that right? More figures would be helpful.

    Background - I worked for years only with a magnetic loop under the roof. It worked OK, but I was always happy when I had the chance to work with a normal wire :-)

    ReplyDelete
    Replies
    1. Good afternoon Hajo, yes the loop was several db below but the loop is in a bedroom not a very ideal location. I am working on the bandwidth of the loop at the moment. Once I get the loop outdoors maybe on the deck I can maybe get better results.
      Mike

      Delete
  6. Hello Mike, which of the two frequencies did you use for the loop? For OL5Q the difference in SNR was not that large. 11 dB vs 7 dB.
    Good to see that the loop is working well.
    There are many "things" that will influence the test. I should say, just use the loop and see what is possible. Good luck and have fun. 73, Bert

    ReplyDelete
  7. Good evening Bert great to hear from you, the loop was 14.050 and 7.032.
    Mike

    ReplyDelete
  8. Hi Mike,
    After receiving my Alex Loop earlier this week I am into evaluation. Interesting enough I came across your blog this week as well, great find. On the KX3 do you use the ATU with the A Loop? I see comments about the front and back of the loop. How would describe the front? I also want to add some length of coax. I did find the loop well constructed with one slight problem, the top clamp does not fit over the top of the mast. I added a plastic piece that slides into the top of mast and allows the clamp to fit, 5 min. fix. Now on to some performance comparisons.
    73 K7KKI
    Dale

    ReplyDelete
    Replies
    1. Good afternoon Dale, I do not use the tuner on the KX3 as I found it will lower the SWR on that frequency you are on BUT as soon as you move to another part of the band the antenna will not tune properly. I have added some extra coax via an SO-239 female to female connector. You have to use trial and error with the length of coax. I found that some lengths to not agree with the Alexloop and it is very hard to get a low SWR.
      Mike

      Delete