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6 Meter/50mhz Magnetic Loop For FT-8 And More

Discussion in 'Amateur Radio News' started by KJ4YZI, Dec 8, 2017.

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  1. KJ4YZI

    KJ4YZI Ham Member QRZ Page

    Here is a 6 meter magnetic loop that I purchased from Bob, VE3UK. It is precision CNC made and developed by Bob himself. All aluminum, at 18 inches and 1.5 pounds, anyone can store this, use this and move this with no problem. I can't wait until 6 meters opens back up again. Super easy to tune, operates 50-54mhz at 100+ watts and can be assembled with a screwdriver and 5 minutes of your time. Check out the video for more details.

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    Attached Files:

    KK4CCA, AC7DD, NF3R and 6 others like this.
  2. KK5JY

    KK5JY Ham Member QRZ Page

    Nice metalwork on your antenna. What does it have to do with FT8?

    Fixed-tune STLs are fine as long as they are indoors. When installed outdoors (or in attic spaces), the heat/cool cycles will cause the center frequency to drift, as the metal expands and contracts. It would be interesting to see how much this antenna drifts over the temperature range of a typical US city. Maybe you could test that in another video sometime?
    AK5B likes this.
  3. NU4R

    NU4R XML Subscriber QRZ Page

  4. W1YW

    W1YW Ham Member QRZ Page

    What does this have to do with FT8?? Also, there is no ham allocation at 50 milliHertz....
    MW1CFN and VE6MRV like this.
  5. W5LMM

    W5LMM Platinum Subscriber Platinum Subscriber QRZ Page

    He said FT-8 AND MORE. Nice video, interesting antenna, thanks!
    Don't know why you people always have to attack.
    WD0CCC, KB2HSH, AC9LV and 19 others like this.
  6. AD5NL

    AD5NL Ham Member QRZ Page

    I like the idea of buy-to-learn in the video.

    I bought a W2LI mag loop a few months ago. This is a mag-loop that is being sold (I believe) as a club fundraiser for a group in New Jersey.

    The stock loop is made of LMR400 and is about 9 feet, and tunes 17 (barely), 20, 30 and 40 (barely). What is neat is that the loop connects to the capacitor using standard SO-239/PL-259 hardware, and the LMR400 coax is supported by PVC (easily got at the local Hardware Big Box Store).

    Naturally, I have made extensive mods. And learned A LOT about mag loops in the process.

    I documented some of them on reddit (/r/RTLSDR) recently. My first mod was to use 26 feet (I think I put 28 in my reddit post, but 26 - 28 feet should have roughly the same effect). With the "big ass" loop attached to the capacitor, I was able to tune 40 (really good), 60 (good) and 80 (OK).

    I also added some binding posts to throw on fixed capacitors in series and/or parallel, which allows me to tune down to 160 (really lossy but better than hamstick, around 2 percent efficiency) or 30 (really, really good).

    I also found out a couple of days ago that by making a 4.5 foot loop I could tune 20 (barely), 17, 15, 12, 10 and 6 meters. I doubt the efficiency is good below about 15, but then again I still have my 9 foot stock piece of coax for the "middle bands."

    The great thing about the W2LI loop is that it was designed "capacitor first", and uses cheap interchangeable parts for the loop. So it means that the one purchase can be modded and reused and repurposed over and over again. And of course it easily breaks down for storage and such.

    (I think the Alex Loop and Chameleon commercial loops follow the same design principles, but W2LI is cheaper and as noted I believe some of the proceeds go to help the club).

    I like the build quality of the CNC'd loop, but by starting with "loop first" it is much more limited. Maybe better for fixed operation or a dedicated Sixer. Definitely more durable. But maybe not as good an educational tool?
    KK4CCA and K7BOA like this.
  7. VK3YE

    VK3YE Ham Member QRZ Page

    6m with small loops is a lot of fun in the summer sporadic E season.

    A demonstration.

    KK4CCA, K2UA and K7BOA like this.
  8. ND3U

    ND3U Premium Subscriber QRZ Page

    I was under the impression that allocation was the frequency range amateur radio operators are allowed to utilize. The band plans (amateur radio) were something compiled by groups like the ARRL but are not LAW, just suggestions. Correct me if I'm wrong but you can use any mode anywhere on the band as long as your licensed for that portion of the band. So, you can use FT8 anywhere on 50mhz. Of course having specified frequencies helps in finding contacts to converse with.
    KU4NJ, K4DXG and W7GST like this.
  9. W7GST

    W7GST Platinum Subscriber Platinum Subscriber QRZ Page

    Maybe it was a type o ?
  10. W1YW

    W1YW Ham Member QRZ Page


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