Building a Half-Wave End-Fed Antenna For 6m, Part 1.

Your videos are never too long, they're always too short!

Hi Gil, 73 PY2SNN Sebastião! Good job!

Fascinating stuff, I learned a lot and look forward to Part 2. Thanks.

Thanks for the video Gil. One simple way to see if there is common mode current in the coax is simply touching it and/or moving it while looking at the VNA. If the curve changes just by touching or moving the coax you know you have common mode currents. From experience it’s almost always necessary to have a 1:1 balun / choke in almost any kind of antenna to eliminate cmc. In verticals with radials on the ground you can get away without it but .. losses..

Interesting and educational video. You always have most informative videos and I enjoy them. Please keep them coming.

Interesting expirement Gil, thanks for sharing. It will be interesting to see which transformer you decide on.

Great experiments, Gil - thanks!

Great vid, as usual, missed you of late and I assume you’ve been busy. Thank you for the time, effort and editing to put these videos out on YouTube for us to enjoy and learn from. 73 de M0AZE Mike 👍🏻👍🏻👍🏻

An EFHW is a full sized antenna but it's not a balanced antenna, like a dipole or a G5RV so that's where ( I believe ) the discussion about counterpoises comes from. Without a counterpoise, the shield of your coax will do the job of the counterpoise, but at QRP levels you probably won't notice that. Thanks for sharing the design for a 6m version, that would be great for portable use.

Hi Gil, thanks for your videos! I built myself the EFHW with an FT114-61 core (2w:14w with a 68pF silver mica on the primary), used with a success on 10m and 6m (100W ssb). The SWR of the transformer (w/ the capacitor) itself is 1.3/18MHz, 1.0/21-28MHz, 1.3/50MHz here. The attached antenna wires cut into resonance do not change the SWRs. PS: no c/p used, a cap coupling via the coax works. Best 73 Igor de OM1ZZ

As always very cool video. Would love to see more about how the antenna wires are positioned during testing.

Great Video Gil.

Good job Gil. I have just started having a play with EFHW at HF using a 49:1 after extensive success with non-res EFLW and 9:1 with good tuner. Seen various rules of thumb for EFHW using 0.05 WL c/p which I guess can also be tagged to radio earth nut. Probably important QRO to avoid RFI bites. Low-ish power (say <50W) then the coax braid likely ‘picks up the slack’ and you perhaps don’t notice. In any event, a tiny 300mm c/p on 6m band is no biggie and can just lay in your backpack or put it down your trouser leg to keep you warm hi ! Simple experiment would be easy and worthwhile. Best 73 Nick M1DDD

Inspiring, thank you.

Nice video Gil, cheers

Excellent.....waiting for final result.

73 Gil , une petite réalisation bien sympathique , j'attend avec impatience la Partie 2 .

Merci Gil, j’ai hâte de voir la partie 2.

Without a counterpoise wire the coax feedline acts as the remainder of the antenna. What I hear people say is that because the EFHW is fed at a high impedance point the shield current is low and therefore not a problem. But this is not entirely true. The impedance at the feedpoint is high, so there the shield current on the coax is indeed low. But as you move further down the coax, towards 1/4 wave away from the feedpoint, the shield current gets higher, in the same way as the EFHW wire itself sees a higher current in the center (at 1/4 wave from the end). When you like to add a CM choke in the feedline, the best way is to place it not at the 49:1 transformer but further down the coax where the impedance is lower and therefore the CM choke more effective.

The advantage of the halfwave end fed is that it does not require a ground plane and it has 3Db gain over a dipole. It also does not have the high radiation angle or multi lobes of the 5/8 or 3/4 wave antennas that still require a ground plane. Halfwave is very popular with wood sailboaters. Halfwave on a portable is a good choice.