Does anyone here have experience with mag Loops?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by G4SEB, Sep 6, 2020.

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  1. KD9PQB

    KD9PQB Ham Member QRZ Page

    Back to the OP - I just got my license a couple of months ago, even though I'm 50 years older than you, so I don't know a great deal like some of these folks.

    I have a Chameleon mag loop plus with the two piece aluminum loop and I have a 133' long uneven dipole in an inverted V with the peak at 35' and the ends at about 15' and 10'. I don't know why but I get as good or better reception from the mag loop. I can't say on transmitting.

    I was cautioned by one long distance Elmer against a mag loop as my first antenna because I might find it too frustrating to tune. It took me a while to figure out the drill with tuning but once I did figure it out it's not as limiting as some people make it out to be. Despite the high Q (narrow range in which it is tuned) you can scan quite a ways from optimal tuning and still pick up transmissions before you have to retune. I seem to be able to tune mine by ear well enough to scan an area and pick up signals and then bring them in by fine tuning. Nice thing about a mag loop are you don't have to have it off the ground more than the diameter of the loop and it's easily moved. It is directional so it helps to have a tripod that swivels easily. We have a metal roof so I like to sit next to it out on a deck so I can tune it and reorient it while I scan.

    The Chameleon isn't made to be left outside so at some point I would like to build one or more that are more band specific than the Chameleon with remote tuners and rotaters that are weather-proof that I could leave out.

    I've got plenty of land and no restrictions so I am hoping for a tower in the not too distant future so maybe loops are a phase, but I do think they are cool.
     
    PU2OZT and AK5B like this.
  2. NG1H

    NG1H XML Subscriber QRZ Page

    A bit late to the discussion but I can DEFINITELY confirm this one. 20m somewhat inverted V dipole at @ 35'. The house roof is about 20' away to the east and higher than the antenna. To the west the homes are lower.

    To the east reaching the US east coast is difficult and Europe/Mediterranean/Africa is almost impossible. To the west I have little problems with Japan, Indonesia, Australia, New Zealand, etc.

    Would a 100'+ tower be great? Of course. But the bulk of the improvement appears to be just getting it away from the ground and above the immediate construction.
     
  3. G0VKT

    G0VKT Ham Member QRZ Page

    For a 3/8 antenna do the radials still slope at about 45 degrees? Tried looking up that size of antenna and only get hits on 3/8 mounts.
     
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    Read this recent forum thread.... particularly #2, #5, #9, and #43.
     
    WD4ELG likes this.
  5. WA7ARK

    WA7ARK Ham Member QRZ Page

  6. AI3V

    AI3V Ham Member QRZ Page

    I don't understand the fascination so many hams have for "off center fed" antennas.

    The majority of posts in this forum are questions on how to solve the issues "off center feeding" causes.

    And none of the solutions are particularly reliable or effective.

    Consider somewhere like tbe Navy relay station I was at.

    Not a single "off center fed" antenna.

    Consider the Intelsat earth station I worked at.

    Not a single "off center fed" antenna.

    Consider the millions and millions of public safety antennas.

    Every single one uses quarter wavelength radials.

    Every

    Single

    One.

    But Rege, my YaeComWood covers 9 hf bands.

    And the transmitters we had in the navy covered every hf frequency...

    It is so much easier to get a full wavelength loop, a half wavelength center fed dipole, or a quarter wavelength vertical with 3 or 4 radials to work, and work every time.

    Why would you deliberately shorten the radials in a attempt to change the feedpoint z, and in the process introduce all sorts of nasty side effects, especially considering the near impossibility of accurately measuring a 1:1 vswr, the appearance of "common mode", when a modern auto tune rig adjusts itself for the whopping 1.4:1 vswr of a theoretical Marconi or Hertz.

    But "gimmick" antennas sure are good at making the guys thay sell them money...

    As allways, YMMV :)

    Rege
     
    WD4ELG likes this.
  7. G4SEB

    G4SEB Ham Member QRZ Page

    Once again sorry for all the late replies! :) I am very very busy at the moment, so I am generally replying every few days.

    Yeah, the general consensus is that my dipole is 100% useless. I will have a research into making one of these, and do some experiments.

    I haven't really thought of this. Getting Planning Permission is a no go. It's expensive, and I think my neighbours will probably object to it. The MFJ-1979 seems a really good antenna I could try out! Quite inexpensive as well, I think I will give this a try, since most DIY antennas seem out of the option with my restrictions. With my antenna at the moment I am not going to participate, as I think quite frankly it will be pointless. Will let you know how everything goes!

    Would 5 metres be enough? I am in a built up area with lots of houses, so I still don't think it will work. I think to be honest a portable vertical suggested by KF5KWO will work best. Thanks for the tips! :)
     
  8. G4SEB

    G4SEB Ham Member QRZ Page

    I think I am getting a portable vertical antenna. Live very close to the Peak District, so getting to a high up place isn't a massive issue, just inconvenient. Hopefully I will have much much more success once I get this all sorted, thanks!

    What is restricting height is my parents. They don't won't a long wire antenna going right across the garden 24/7. An unfortunate situation at the moment.

    With me living in a very built up area, I don't think the STL will really work very well, as there are no extremely clear views in any direction. Also I really don't have enough to spend $500 on an Antenna. So far I don't even know if I will enjoy the hobby after I have got the antenna working. I need to keep my costs down. As I have also mentioned I think at this point I will have to go mobile with my operation, and get a portable vertical or other antenna.

    Either way I have my license now, and that lasts for all my life, so really there isn't a rush to do anything. Thanks for the help! :)

    Hi. I am currently using a full wave Dipole, which resonates at 14mhz. I used a NanoVNA to check this out. I don't live in an apartment, but I am in the pretty much exact same situation.
    Mobile does seem one of my only options. I was thinking about a portable vertical antenna, however your idea is a lot more portable for walking with equipment!

    If I went with an antenna similar to that, I would probably look at one of the Sotabeams ones with one of their carbon fibre masts. Seems very portable, and I live not too far from where they are based. Either that or I might make my own. Thanks for the tips!

    Hello! Unfortunately, I would probably say no chance I could do your idea. If it was a regular church, then possibly, however the 'Crooked Spire', is actually famous for it's sloping spire, hence why it is on my QSL card. The only way you can go up the tower is via pre-booked tours (Which cost money), and the church is Grade 1 listed, which means I can't do anything to the physical structure.

    My dipole is 10m on each side, 20m in total. If I said the opposite somewhere else, I may have been very tired when replying to all the comments xD

    Unfortunately I live very far from the Sea (Live not too far away from the furthest point from the coast). STLs are very expensive premade, and I 100% agree with your warning against building one. I already looked at it and the parts are extremely expensive, and making a good one, like you said, takes a lot of expertise. I have my license for my whole life, so there are plenty of opportunities I could try an STL out. Getting a premade one is out of the option as most high performance ones as 500$ plus, compared to a vertical antenna or Sotabeam which I could get for around $125 ish.

    I think at the moment my best chance is portable operation. I'm looking at either a portable dipole or a Sotabeams BandHopper II. Thanks a lot for the very valuable information, and 73s!

    This reinforces what AJ5J said about me not attempting to make one of these. The extremely high voltages involved can cause quite a lot of damage, and it isn't worth the risk of property damage or injury.

    From what I have heard so far, my current antenna is extremely useless. Thanks for the tips though! ONce I have purchased and set up my new Antenna I will have a listen out for the Beacons! Thanks
     
  9. G4SEB

    G4SEB Ham Member QRZ Page

    I will reply to pages 4 and 5 tomorrow. I have to do some school work :)
    Sorry for the wait. I am really glad about all the information you have all given me! Fingers crossed I can get on the air soon
     
  10. KF5KWO

    KF5KWO Premium Subscriber QRZ Page

    Wow, didn't realize it was expensive to go through the planning process. That's a shame, and about the neighbors as well. Them's the breaks! No big deal though, because operating under restrictions makes us focus even more on placement, feedlines, noise reduction, etc. Compromises of course, but they won't keep you off the air. I personally used to hate the fact that I have these restrictions and have to resort to indoor or hidden/stealth outdoor antennas, but I've changed my mind on it. I take it as a challenge. It's a quest -- a quest for fun! :)

    And much of ham radio is experimentation, and what works for one ham may not work as well for another, it all depends on your location, your immediate environment, etc. As an experimenter, you'll never go wrong, because you'll find out what does and what does not work for your QTH, and you'll refine your skills.

    Be sure to search youtube, qrz.com, eham.net, et al, for "MFJ-1979" -- or whatever option you go with -- for tips and tricks. And I recommend that you order NOT from MFJ but from another dealer: DXengineering comes to mind. Terrific customer service.

    Be sure to let us know how it works out for you. Posting your results helps all of us when we are searching the forums to see how other people use different products. Good luck! :)

    73 de Jeff, KF5KWO
     

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