Chameleon DIY Magnetic Loop Starter kit First Build

Discussion in 'Amateur Radio News' started by OH8STN, Feb 19, 2017.

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  1. OH8STN

    OH8STN Ham Member QRZ Page

    Hello operators
    starter-kit.jpg For those interested in the DIY Magnetic Loop Starter Kit from Chameleon, this is my first build video using that kit. The video details two different models of a man portable magnetic loop antenna.
    • The first is a 40-10M single turn loop based on the Chameleon P-LOOP.
    • The second is a 80, 60, 40M, double turn loop with switched capacitor to quickly convert between 80, 60, 40M and 40-10M.
    You can watch the video here.


    Amongst my build goals was a desire to build a practical field deployable magnetic loop antenna, which would fit easily into my skipulk or backpack. I certainly could have build a larger more efficient system, but only at the expense of mobility. The design is heavily based on aspects of the Chameleon P-LOOP and Alexloop man-portable loops.

    I hope my video helps other beginners get started with their Chameleon Magnetic Loop starter kit, and would love to see builds from other operators who have also chosen to use this starter kit.

    73 de oh8stn
     
    W5KV, AA8GK, W7GST and 5 others like this.
  2. K5TED

    K5TED Ham Member QRZ Page

    You paid $99 plus shipping for a $20 capacitor, some UHF connectors and a piece of feedline.
     
    AD5KO likes this.
  3. VA7UO

    VA7UO Ham Member QRZ Page

    Yeah that's it be condescending and rude.. What is wrong with you?
    Maybe he is getting into the radio side of things on HF..Myself, V/U and microwaves, it's comments like yours that throw people off.
     
    N1PRH, AA8GK, W7GST and 8 others like this.
  4. VA6ERO

    VA6ERO Ham Member QRZ Page

    nice guy shows how to assemble loop and grumpy old ham jumps on him.
    sure hate to have k5ted,s life.not too good i think??
     
    W7GST, K0PIR and OH8STN like this.
  5. K7LZR

    K7LZR Ham Member QRZ Page

    Very good, and perhaps this will inspire some folks to try their hand at building a small loop :).
     
    N1PRH, K3RW, AA8GK and 2 others like this.
  6. F4HPX

    F4HPX XML Subscriber QRZ Page

    if this costs 99$ it's still more interesting than finished product Chameleon is selling and you have some fun bulding it and understanding how this is working.
    I have a commercial version and not fully tested yet but I would not expect miracles on 40 or 80 (with extension).
    Surely it does tune and possibly receives pretty well, but taking into account loop size and loop thickness the transmitting performance will be quite bad
    If already topped at 20 to 25W PEP you will get probably 2-5W equivalent radiating on 80m comparing to the dipole.
    But it shall work well on higher bands 15-12-10 -I had good experience on 10m with FT817ND so 5W out.
    The only issue is the propagation getting worse on these bands recently.

    You can still experiment with longer loop and thicker one using copper or aluminium tubing with higher diameter - performance will increase on lower bands.
    But capacitor will have some limits both for power/voltage and frequency range coverage.
    For QRP shall be still fine.

    73 Thomas
     
    N1PRH, OH8STN, AD5KO and 1 other person like this.
  7. KI6TRA

    KI6TRA Ham Member QRZ Page

    A dipole will almost always be more efficient than a magnetic loop...but you need to be able to deploy it first. I wonder how many QSO's people can do with a 40M dipole deployed in their living room:



    That was from a customer few months ago:

    "Just for fun… F-loop (standard) from Aug 28. Indoors. 5 watts. I’m a newly upgraded HAM to hf and really enjoying it. Your antennas are good stuff! Cheers, Mark"

    [​IMG]

    A more powerful magnetic loop will be released in few weeks from now:

    http://us3.campaign-archive1.com/?u=e1cdcbe4da58e8277f75bd6b9&id=cdf412e790&e=[UNIQID]

    Carl
     
    W7GST, OH8STN and K0PIR like this.
  8. KF5FEI

    KF5FEI Ham Member QRZ Page

    FYI for those wanting to build their own QRP mag loop -- Midnight Science and several other vendors sell the dual-section 365 pF caps and the reduction drives. Typical price is $20-22 for the cap, $11 or so for the reduction drive, and $3 or so for the reduction drive bracket.
     
    K3RW, W7GST, K2MOB and 2 others like this.
  9. F4HPX

    F4HPX XML Subscriber QRZ Page

    Agreed
    not much space in living room for a dipole
    In US homes are often made from wood so you can use it possibly inside.
    I tried it in Lisbon in 20 something storey hotel - concrete and steel
    Did not work for me even close to the window. Ended by putting 30 feet of thin wire outside on small fishing rod because I could slightly open the window. The staff did not see that despite the hotel was lit entirely from outside...

    What can stop us to make a QSO done!
     
    OH8STN likes this.
  10. K2EIR

    K2EIR Ham Member QRZ Page

    OH8STN, Thank you for posting publicly accessible videos. I've seen a number of your loop videos and find them interesting. I was glad to watch them. I encourage you to keep up the good work!

    Attention K5TED:

    Anyone who has to order parts these days knows that it often means going to multiple vendors each with its own shipping charge, typically $9 per order stateside. A capacitor such as shown may cost $20 to $25 and the knob, vernier, and mounting plate $20 or more. ( sub total so far $45 + $18 shipping). While LMR 400 can be had for $0.65 per foot, sometimes you can't buy limited lengths alone. A 12 foot or 16 foot prepared jumper may have connectors on it and will be in the $20 range. ( Add $20 + $9). Oh, and don't PL-259 and SO-239's sell for about $5 - $7 each depending on quality? Didn't I see 5 of them? So one approaches $99 very quickly.

    ****

    Although loops may be less efficient than a dipole, the radiation pattern may be more favorable for distance, especially if the antenna must be height limited to just a few feet above ground, and that is why many choose to employ them. They also may yield noise reduction on receive.
     
    W6TUS, K3RW and OH8STN like this.

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