NEW CHA F-LOOP 2.0 from Chameleon Antenna is NOW AVAILABLE!

Discussion in 'Amateur Radio News' started by KI6TRA, Apr 30, 2017.

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  1. WB0ZRD

    WB0ZRD XML Subscriber QRZ Page

    Small loop antennas work pretty well for what they are. People just need to realize what they are buying, with the smaller voltage rated tuning capacitor you get smaller RF power handling capability. If you want big power you need a big capacitor. All loops have pretty darn narrow usable bandwidth which means if you spin the dial on your rig very far at all you will need to tweek the tuning on the loop. The smaller you go in loop diameter and the diameter of material the loop is made of means less efficiency. These are good antennas, I have one that I use when out RV camping. Small and easy to take along, I also have a Hustler mobile antenna mounted on the rig, most of the time the loop performs better than the Hustler, but it is more fiddly to keep it tuned. Just my two cents worth coming from someone who has been building and experimenting with loops for awhile.
     
    AK5B likes this.
  2. WU3U

    WU3U Premium Subscriber QRZ Page

    I have the new CHA P Loop 2.0 and really like it. I have nothing to do with this company but I will say that I had the Alpha loop first and there is a night and day difference in the quality between the two. What sold me on switching was the better quality design and materials along with the power compensator that allows you to do either 60 or 65 watts SSB, can't remember the exact number. I've only had it a few weeks and haven't tried the power compensator yet.

    I've made a bunch of QRP contacts with it, mainly stateside being that the bands have been so so lately but the funny thing is that I've never told people that I'm working QRP. A couple of times I had to repeat my call but for the most part the exchanges have been no different than using the radio in the shack. In the shack I can usually work any station that I can hear but the loop isn't quite that way. You'll make a lot of contacts but not every one that you can hear.

    I've found that it's almost a necessity to run the antenna into a splitter and then send one side of the splitter to the radio and the other side to an antenna analyzer. It takes a little while to get used to how touchy the tuning knob is, even with the reduction drive. A fairly small movement can make the difference between 12:1 SWR and 1.2:1 but you get used to it and can quickly dial up a good SWR.

    I've only had one time that I set it up and didn't make a contact. I went in the house and turned the radio on and realized that the noise level was pretty high so is suspect that was probably the issue being that 5 watts doesn't cut through the noise very well. The sharp null in tuning seems to make the loop antenna a lot quieter than my long wire.

    Are these worth the money? That's still very debatable. It works very well but I could have built something for less but I also feel there is something to be said for the engineering time and getting something that's probably constructed a little better that I would have done delivered right to my door ready to use. I'm not sorry that I spent the money.
     
    K3SX, WD4IGX, OH8STN and 1 other person like this.
  3. KY5U

    KY5U Premium Subscriber QRZ Page

    The new B.C. antenna.
    crack.jpg
    A true case of form over function....
     
  4. KD6JUI

    KD6JUI Ham Member QRZ Page

    These antennas operate best within a certain range of frequencies. With the size of this one being on the small size, I wouldn't expect much in terms of antenna efficiency on the lower bands, 40 meters and below. Also, I have heard that some of these antennas (not sure about this one) have problems with -- when you bring your hand up to make a knob adjustment -- it will throw the SWR off -- like it's "touchy" !
     
    AK5B likes this.
  5. WU3U

    WU3U Premium Subscriber QRZ Page

    As mentioned above it can be touchy but you get used to it. Depending on where and how you set it up it can work as you have described it. Some days I can pull my hand away and the SWR stays rock solid, other days pulling your hand away may change the SWR a little. When that happens I just very slightly raise the SWR on either side of the null and then pull my hand away and watch the analyzer. You can pretty easily find a point that when you pull your hand away the SWR drops to a prefect level. Many times I can get in the 1.1x:1 or 1.2x:1. Not a big deal.

    It seems like with the loops that use LMR400, how you deploy the antenna really makes a difference in how low you can get the SWR. I think with the model shown above with the aluminum loop, that probably makes things a lot more stable. With mine having LMR400 I've found that you need to have it as close to a perfect circle as possible. I also look at it from the side to make sure that the LMR400 is even with the side of the capacitor and that one side of the loop isn't forwards or backwards in relation to the capacitor box. Once you have it setup, it's stays fine. Probably the most important thing is that you have to have the coupling loop at the top connected very tightly and lined up very well below the main loop.
     
    Last edited: May 1, 2017
    AK5B likes this.
  6. AK5B

    AK5B Ham Member QRZ Page

    As a strong proponent of STLs (small [electromagnetic] transmitting loops) I am glad to see that this manufacturer is trying to step up the game by using a solid aluminum element (albeit in two pieces which isn't so good) and the construction quality appears to be on the better side than most/all of the other commercial loops out there (with two major exceptions; the high-end Cirro Mazzoni STLs from Italy and VE3UK's TIG-welded loops from Canada).

    On the other hand, I am again saddened by the erroneous claims that the manufacturer makes about their "magnetic field" properties and efficiency which may well give rise to false expectations to many new or unaware hams in the process.

    Indeed, small transmitting loops that are well-made with the best construction practices can give surprisingly good performance and are a godsend for us that live in HOA situations or must operate portable---but everything comes at a price and not necessarily that price is paid in dollars or Euros or what-have-you. One cannot cheat the laws of physics!

    To get optimum performance one must use a vacuum variable capacitor and a continuous radiating element with as few soldered or welded connections as possible. Using any less than these optimum methods results in that the efficiency and transmitting performance will suffer greatly.

    The main radiating element should also have as large of an O.D. as feasible and also be close to 1/10th wavelength diameter as possible, too---which is beginning to get large at 20M and below, e.g., 5 feet for 20M and about double that for 40M; I use a 7-foot loop for 40M that can handle 600 watts and even then, it just begins to cut the mustard when conditions are good. Yes, I know, dx and reliable regional contacts can still be made with 3-foot loops on 40 meters and above---but it gets more and more difficult the more compromises one makes.

    I also realize that this Chameleon doesn't pretend to be ideal or optimum in the true sense of the word and that the targeted market is probably the low-power digital crowd where something like JT65 can get through on a wet shoestring---but I still think prospective users of any STL design do their homework before plunking down lots of hard-earned money for a compromised commercial version that almost purports to be the Holy Grail.

    I do hope that buyers of this antenna achieve good results and that the company continues to make further improvements in its designs---but with a finicky antenna design to begin with that is a task often better achieved by someone willing to invest time and resources in building in his own once a good understanding of how and why that they work---and what it takes to achieve good results is fully comprehended.

    For those not familiar with STLs and possibly wonder what I am going on about---please read Leigh Turner's (VK5KLT) excellent 32-page treatise for a fuller exploration of this fascinating antenna here:
    https://www.nonstopsystems.com/radio/pdf-ant/article-antenna-mag-loop-2.pdf
     
  7. OH8STN

    OH8STN Ham Member QRZ Page

    I don't have the F-Loop 2.0 yet, but like all the gear I review, I'm looking forward to taking it apart to see what it's all about.
    The original F-Loop (and I imagine this one too) is set up like a modular system. You've got a basic kit which was 60?/40-10m. Add the double loop kit (which was included in the original) to get 80m. There is also the F-Loop plus (included all of the basic kit, double loop for 80m) aluminum radiator kit. I have the original F-Loop plus in the attic above my shack on the remote tuner rotator which works well for me.

    The breakdown size of the basic F-Loop is pretty good. I only take the basic or double F-Loop to the field, although I did do RaDAR Challenge April 2016 mobile with the plus model. It's also self-supporting to sit on a table, bench, desk or can be tripod mounted if needed.
    The thing is, it's designed in the way that considered how the operator would work with it. So imho, usability was engineered into the design. Looking at the math, there could be better performing loops, either homebrew or commercial, but nothing easy to setup and work with. Definitely the F-Loop is the most well thought out loop I've worked with.
    The specs written in this thread seem to be meant for those familiar with the F-Loop philosophy, and can be confusing for those new to it. I think more effort focusing on the philosophy, options and specs, minimising the long marketing text, would help people understand the methodology.

    My hope for the updated F-Loop is even smaller breakdown size, and perhaps the various main and coupling loop options like the latest P-Loop 2.0.

    I've done some amazing work with the original F Loop, and I can't wait to get the update.
    Hope this helps.

    Julian
     
  8. N8NN

    N8NN XML Subscriber QRZ Page

    According to the specs, I can improve my signal by one to two s-units by using a 1/4-wave vertical. Portability comes at a price. If a loop is the only way to get on the air, the CHA F-LOOP 2.0 is a solution. Being limited to 10 watts CW and an antenna one or two s-units below a vertical is a real challenge to "being on the air".
     
  9. W4OP

    W4OP Ham Member QRZ Page

    Please tell us why is the H field better than a non-magnetic loop antenna? In free space all antennas have an E/H ratio of 377 Ohms. Do your antennas not follow this?
    What does Q resonance of 17KHz mean? Is this the 2:1, 3:1, -3dB bandwidth? Your statement tells us nothing. I would also challenge the phrase of "most efficient". I know of another commercial loop that is less expensive, extremely well built and has higher efficiency.

    Dale W4OP
     
    Last edited: May 2, 2017
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  10. K4WBF

    K4WBF Premium Subscriber QRZ Page

    I have the first version of it and absolutely love mine. These are great for restricted community's and apartments. The RTR add-on is a great addition for remote tune and turning.
     
    OH8STN likes this.

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