Need advice on HF loop antenna

[bobruzzo]

There is a possibility that my wife and I MAY move to a condo in the near future when she retires. This cause me some concern since I have a few antennas outside our house. I saw a Youtube video of a guy who set up a 80-10 meter loop antenna on his top floor balcony and gets decent results. I looked online but still not sure. I would like to find a high quality GOOD loop antenna. Even if its for 40-10. I would still like to be able to use HF and I know condo is very limiting to the hobby. I dont want to build one cause my eyesight isnt what it used to be. I have seen them go for over $1000. Not sure what to get so I need guidance. I can thin the antenna herd and should be able to use my little Diamond x50 for vhf/uhf/DMR and my OMNI X for my scanner. Those antennas are small enough to use on balcony.

 

[K4EET]

Hi Bob,

Firstly, I enjoyed listening to The Platinum Collection. Very, very good composition!

Second, consider building a magnetic-loop antenna (MLA) for Tx/Rx on the HF bands. With some RG-8, RG-213, or LDF4-50A for the main loop, copper tubing from an ice maker line for the small loop, a tuning capacitor (pF determined by calculation), plastic box for the tuning capacitor, an old camera tripod, and some miscellaneous small hardware, you can build a MLA for under $65 that would easily handle 25 watts SSB/CW from 80M to 10M. A friend of mine has already built a MLA and tested it on 80M to 10M. The power handling capability is mostly limited by the plate spacing on the tuning capacitor. Note that RF voltages can easily exceed 5kV on a MLA.

I am building my MLA out of the LDF4-50A hardline so that the main loop stays circular without bracing. I am considering using a vacuum variable capacitor and a stepper-motor to allow the MLA to handle more RF power and to make the capacitor remotely tunable. Here is a link similar to what I am doing:

Magnetic loop antenna project – VK2RH ham radio

Right now, I have an air-gap plate tuning capacitor from an old antenna tuner. I am looking for a 250pF +/- vacuum variable capacitor at a good price from a local hamfest. What I have now will allow for about 100 watts RF. I would like to increase the power limit to 300 watts RF for my Drake TR7 which puts out 1/4kW RF.

Use Google to search for:

• Magnetic Loop Antenna Project
• Magnetic Loop Antenna Calculator

You’ll find plenty of design information. I like this antenna calculator:

VK3CPU Magnetic Loop Antenna Calculator

Keep us informed on what you end up using at your condominium. Keep in mind that you may need to hang plastic plants from your antennas to camouflage the antennas due to HOA restrictions. LOL!

73, Dave K4EET

 

[bobruzzo]

Hello Dave

Thanks for the info, I will read through the article in link and I can get help building this at my radio club. They have a big building with tons of scrap metal and parts. I always run barefoot so the low power is OK. Plus the big hamfest is coming up next month at Deerfield in New Hampshire so I will spend a lot of time there and look for some parts. I would like to move to NH but my wife doesnt like the long cold winters, but I can handle it. Hahaha The Platinum Collection.....I am a guitar player and used to go out playing at an old hotel lounge a few towns away. A bunch of us would get together and jam. I did that for a number of years but I really wanted to do my own thing. I am not an entertainer so I decided to learn how to play keyboards and bass enough to create my own music. So thats my other hobby besides radio. I just do it for fun and not as active recording as I used to be.

 

[popnokick]

Loops - The RadioReference Wiki

wiki.radioreference.com

 

[K2KOH]

Chameleon F Loop I have the older F Loop 2.0. I like it, I run it QRP with my IC705 and sometimes my FT817ND. When I’m not out playing, I use it in the house as a receive loop for HF Aviation