Thursday, November 7, 2013

Learning more about the Alexloop

What turning the loop can do
As times goes on and I use the Alexloop more and more I am coming to realize that this antenna may not be a bad choice for my condo antenna. The loop is small and I thought may not preform that well, stacked up against my Alpha Delta DX-EE dipole antenna yes it does not far very well. BUT for limited space, fast to assemble and take down and stealth the Alexloop is a great contender. Recently I have been only using the Alexloop indoors and either on the main floor or my second floor shack. The power has been set to 5 watts and as was said in my previous posts I was able to get into Europe with some decent reports. This weekend using the loop antenna along side my K3 (Up to this point I have only been using my KX3) they seem to get along very well. The tuning of the antenna has been made easier because of the P3 and external monitor. I am able to tune to peak noise using the band scope or otherwise known as the Elecraft P3. Peaking the noise level this way has almost netted me a perfect SWR on all bands. There was only a very minor self tune I had to do in order to get the SWR flat.

Man made noise on the band
I did notice on 30m today there was lots of man made interference and by simply rotating the loop most if not all the interference was eliminated. As well after rotating the loop the signals I was listening to were still there. That to me can be a great bonus once in the city of Toronto and the interference problem may increase and by turning the loop I may be able to rid myself of some of it. I also wanted to know what the loops receive bandwidth would look like on the P3 and I am please to say that's it's great. As for transmitting I have found the loop has to be re tuned anywhere from 10 to 25 Khz depending on the band. This was a good learning weekend for me regarding the Alexloop. I have been toying with the idea of the MFJ magnetic loop as you can tune it from your desk. I have tried to add some extra length to the Alexloops coax and have had some good and bad results with tuning the loop for best SWR. I have noticed as well that when tuning the loop your body has an affect on the SWR as well. You may see a great SWR but once you have moved back to  your radio the SWR goes from your tuned 1.2 to 1 to 2.2 to 1. This is not the case all the time but has happened now and then.
A nice bandwidth with the loop
One other element I wanted to try this weekend was Skimmer, there was a contest on and I wanted to see how well it did. The results were very pleasing and I was able to see how Skimmer can help me. I have played with Skimmer in the past and just could not get it working but I stuck with it this time and am pleased with the results.
Skimmer showing the picture

4 comments:

  1. Hi Mike, I think the loop does an excellent job. Because you do not have another antenna at the moment you will explore this one. Avoiding man made noise with a loop is indeed very good. Did you try horizontal polarisation as well with the loop? 73 Paul

    ReplyDelete
    Replies
    1. Good evening Paul, I have not tried the loop in the horizontal position yet but have to somehow configure the tripod to support it that way.
      Mike

      Delete
  2. Just a note to those who may not be familiar with the MFJ loop. It will operate with 100 Watts.

    ReplyDelete
    Replies
    1. Good morning Dave, true that.....but as for the Alexloop it's a low power loop. As for the MFJ loop I will just be able to use it for QRP operation only.
      Mike

      Delete