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Sunday with my Portable Mag Loop (infosec.pub)

submitted 7 months ago by [email protected] to c/[email protected]

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I don't know many hams nor do I chat with the same hams on a recurring basis, and my wife is only tangentially interested in radio inasmuch as it makes me happy, so I thought I'd be the life of the party and post about the best day on the air I've had yet. My aim is to share my enthusiasm with the world.

I've been a ham for about a year. I'm young (experience-wise) and still learning. Until this weekend I've been using a portable whip on my balcony combined with my President Lincoln for 10 meter contacts. My antenna mounting situation was awfully complicated, so I often left the antenna mounted several days at a time such as on the weekends. This finally bit me when the fine women who were feeding the squirrels next door moved out. The squirrels went ballistic and destroyed my antenna along with wreaking havoc on the rest of the neighborhood. They chewed through the loading coil and the coax! Preposterous. I cannot imagine what they thought to gain from doing so. Nevertheless, it put me out of commission for a while.

I think the math behind magnetic loop antennas is really cool, and I don't have much space, so I decided to try the Chameleon F-loop as my next antenna, the base model. Wow, did I have so much fun today! Tuning was tricky because of that high Q and narrow bandwidth, but I didn't realize how active the airwaves could be when you can hear clearly. My reception was so much better because my noise floor seems to be lower with the mag loop compared to the whip. I also enjoyed the directionality of the loop, giving me a new property to play with to get the best reception.

Thanks for reading!

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[–] [email protected] 2 points 7 months ago (1 children)

Mag loops are AMAZING antennas. Sure, they are a PITA to tune but such narrow bandwidth and high directionality make signals easy AF to pull in!

[–] [email protected] 1 points 7 months ago* (last edited 7 months ago) (1 children)

It’s crazy how much I can hear now. I lost a full S point on the noise floor and the bands are always busy when open. It seems like it’s immune to my local RFI.

FT8 on 10 I would usually see a few stations. Now, sometimes I have to actually look for a free slot because I’m hearing so far out there.

I read that loops can be better beams than a four yagi if mounted too low to the ground not on a tall enough tower, which is an easy mistake on lower bands.

[–] [email protected] 2 points 7 months ago

And if you know the direction of your rfi just turn the loop so the null (sides) face the rfi and it falls off like a rock. The signals are sent and received on the edges of the loop of course

[–] tangycitrus 2 points 6 months ago

I use my mag loop indoors. It's a 40 to 17 meter band loop, but as you say its a pain to tune, even with the lovely built-in analyzer in the G90. I've set it at 7.028 (FISTS CW calling frequency) and I can move a bit up and down without messing up the SWR. I can make contacts around the UK and sometimes across to the continent.

[–] TragicNotCute 2 points 7 months ago (1 children)

I don’t do ham at all, but I’m interested in this antenna you’re talking about. Have any more information about it?

[–] [email protected] 3 points 7 months ago

Yes! You don’t see a lot of magnetic loop antennas in consumer electronics because they’re not very effective at the very frequencies commonly used for technologies like cellular and Wi-Fi. This is a distinct advantage for me because my lease doesn’t allow antennas, but the magnetic loop doesn’t look like an antenna. I’m specifically using the F-Loop developed by Chameleon.

I won’t insult your intelligence by suggesting that you Google the topic, so I’ll just summarize what I think is most important. I think a magnetic loop can be a great antenna because it doesn’t look like most antennas, has a nice radiation pattern that allows some directivity, and can be relatively compact while maintaining reasonable performance. Ham radio antennas can easily be quite large especially for use on lower frequency bands.

I am not an expert in antennas!

[–] knacht1 1 points 7 months ago* (last edited 7 months ago) (1 children)

Nice but pricey.

https://www.dxengineering.com/search/product-line/ciro-mazzoni-automatic-magnetic-loop-antennas/part-type/limited-space-small-loop-antennas?fr=part-type

[–] [email protected] 2 points 7 months ago

Oh it is. I got mine secondhand and it was still expensive compared to a wire.

[–] vatlark 1 points 7 months ago (1 children)

That's really cool, its a world I know very little about. What is an example of something you have listened to or communicated with?

[–] [email protected] 2 points 7 months ago (1 children)

Today I was able to reach New Zealand from the US East Coast for the first time. I don’t generally talk about specific subjects on the air. Mostly, I exchange basic contact information and signal reports. Merely establishing radio communication over such long distances without reliance on the Internet or other infrastructure is fun. It’s amazing to think that with a little radio knowledge you can communicate across the globe. It also pushes me to learn more about radio and electrical engineering.

[–] vatlark 1 points 7 months ago

That really is an impressive accomplishment. Yeah learning more EE seams like a great reason. Aviation radios have all sorts of clever tricks to get a longer antenna. Some WWII era planes would trail their antennas behind the aircraft.