80M Full Wave Loop

[N4AJZ]

I'm thinking about putting up a full wave 80m loop in the horizontal configuration about 30' off
the ground. Will be feeding it 450 ohm ladder line and will be cutting it for 3.505 mhz. It should
tune 40 and 20meters as well with my MFJ tuner. I will using #12 coated stranded wire. I've read
that by using coated stranded wire that I should shorten the calculated length of the wire by 4%.
Does anyone here have any experience with this setup and also feed line lengths for the ladder
line?


Jim/N4AJZ

[graysclassics]

Hi Jim, Did you get any luck with your 80m loop? I am thinking seriously about making one here in the UK. I dont have much of a back yard though but should manage (just) to get 272ft which should be ok for 80m SSB part of band. Wont be a loop as such but a corner fed rectangle at around 30ft. I will also be using the stranded, plastic coated wire which is military spec. The formula most suggest is 1005/Frq Mhz=Lft. Some say add 6%, some say use 4:1 balun, some say no balun, antennas must be the most complicated, but interesting bit of kit in the ham arsenal. Best of luck. Gordon G1NOR.

[K3AN]

Since you're using ladder or window line to feed the loop, cutting it to resonance is not that important. I'd go with 1005/f. Unless you are using a true balanced antenna tuner, you will want to use a balun at the tuner's output (many manual antenna tuners have baluns already built in). Do NOT install a balun at the antenna.

Remember that your horizontal 80 meter full wave loop will be primarily a high angle radiator on 80/75. Good for local contacts, not good for DX. As you go higher in frequency (40 Meters and up) the antenna will radiate more of its signal toward the horizon. On 20 and up it should be a very effective DX antenna, especially if you can get it even higher than 30 feet.

Check out the wealth of information about antennas on the W4RNL (SK) web site, www.cebik.com. They require that you obtain a log-in user name and password, just like this site. There are great articles on many different types of antennas.