Taking Down the Half Square Antenna - Good or Bad Move? Ham Radio Feature

[@PhilG0BVD]

Surprised by the height of neighbours trees! our friends had big trees in their garden they were told the roots is as long as the height of the tree caused so much damage to sewerage pipes and foundations cost them thousands to take down and repair the damage they had done. Great content with the aerial.

[@m7trsradio]

Great video Peter. I am going to change out my Z shape efhw in the attic for a doublet to try. Just waiting for my atu and ladder line to arrive. Looking forward to those videos 👍🏻73

[@chrisg7veo495]

the neighbours tall tree would be good to support an inverted V

[@winstonchurchill6506]

i have used one of those large garden fence posts spike then a couple of brackets connected to the posts extra support been up a year now no probs

[@norbertstepien9185]

Greetings Peter. Just for your info, in Canada we call it an "auger"

[@watersstanton]

Yes I think that is probably the correct name here as well. 73 Peter

[@dieselbushcraft1299]

Morning Peter, I will look forward to seeing your video about the G5RV as I’m looking at different options for portable operating. I was operating last weekend in the Outer Hebrides with a Atas 120a but I find it too much of a compromise between performance and practicality. Incidentally I’m a G3, it was my father’s callsign and I have fond memories of being in his shack on a Sunday morning whilst he was in the top band net. Hopefully I will keep the G3 going for quite a few years to come.

[@watersstanton]

Many thanks David and good on the G3 history. 73 Peter

[@basshorseman998]

Thanks Peter

[@watersstanton]

Thank you.

[@gregtroubles4597]

I think a Bad move ha ha the Half Square works so well and is so so quiet......I'm in process of revising my Half Square making it for 40m.... this will be interesting...

[@m0aze611]

I've have nothing but good results with my G5RV, location change meant a EFHW (also a big fan) on 80 and above. For my G5RV I changed from coax fed to open wire as per original design and the difference was noticeable. There are a few derivatives to the G5 which once I move again will try. Great hobby this/ Thanks for posting. Regards Mike

[@watersstanton]

Many thanks for sharing Mike. 73 Peter

[@bobadkins7377]

Mike I’m strongly considering a EFHW for 80 and up here in Ohio. Very close! How high did you install yours? Is it a good performer? Thanks 73

[@alandrury9955]

Try putting up a straight 40 metre EFHW with a 110uH coil at the end followed by about 2.5 metres more wire. That end section will let you resonate it on 80 metres as well, albeit with reduced bandwidth. Any half-decent tuner will cope with that and give you the whole band. You can even slope the 80 metre section or drop it vertically down and it doesn't seem to mind

[@watersstanton]

That was one of my original antennas and. if you look back you will see the videos I did on this. 73 Peter.

[@dandypoint]

It’s been my experience that a dipole, if you can get it up not much above the height of the half square, has a lot better gain and a broader beam width. That said, my 80 meter Half Square is a killer on 80 meters into Europe from Virginia! The half square I built for 40 it was maybe equal to my fairly low 40 meter dipole ( 50 ft at the time ). I did again notice the pattern was narrow so the dipole was the antenna I kept up.

[@JayN4GO]

You actually used a true half sq. Not an upside down efhw. Feedpoint and current are very different I assume

[@dandypoint]

@@JayN4GO not sure what you mean. Current is the same phase on the wires end fed or top corner fed. Both verticals have in phase current. The top wire should be 1/2 wave with the two vertical sections 1/4 wave. Same as the ones I built. Is his different? Maybe I missed that. If the total length is only a half wave then it’s not a Half Square antenna but an end fed half-wave dipole with the ends bent down or bent EFHW depending on how you view it.

[@JayN4GO]

@@dandypoint interesting , so we can make the efhw a loop or a vertical and expect the same results ? Just use trickery with the transformer? If the end result is the same , why not use 160m efhw as an 80m half square? For some reason I thought the true half squares feedpoint had to run straight away from the top corner for some purpose

[@dandypoint]

@@JayN4GO No. There are two thing that are sometimes mixed up. First you must match the feedline to the antenna to get power into the antenna. Second after you do that you look at the current distribution on the wire. An EFHW or any half wave long wire has the same current distribution along the wire. Zero at ends and max in middle. Any wire longer than a half wave long but end fed has a current distribution that starts with zero at the far end and has current maximums every quarter wave back from the end. However only every other maximum are in phase. If you bend the wire certain ways you can form various radiation patterns. Bending the ends down a certain way on a full wave wire can give you two vertical 1/4 wave wires separated by 1/2 wave and with in phase currents. That’s a half square. A full wave wire center fed will result in the currents in both halfwave sections being in phase. End feeding that same wire will result in currents in the two halfwave segments being out of phase and producing a very different pattern! So you have to look at where the current is on a wire and what the phase relationship is. Making the full wave wire a loop and feeding it at the bottom produces current maximum at the center of the top horizontal wire and also at the center of the bottom wire. Essentially you have two halfwave dipoles spaced 1/4 wave apart with the ends bent down on the top one and up on the bottom one till they touch. Two such dipoles produce insignificant gain over one flat dipole. Regardless of how you bend the wire you can somehow feed it power but the resulting radiation pattern can be anything from complete cancellation of the radiation to significant power gain in a couple narrow directions. Hope brief explanation helps.

[@JayN4GO]

@@dandypoint sure does! Thanks om for explaining

[@Jonshome337]

Do you neighbours mind your poles?

[@watersstanton]

No.

[@RobertLeeAtYT]

23cm, huh? The one advantage of operating at 1.2GHz is the antenna size. For the experimenter, the dimensions are small enough so as to make practical 3d printed fixtures, but are still large enough to work with. 3d printing really adds to the hobby. The fast turn around is satisfying. Also, at these frequencies, submillimeter accuracy and repeatability matters.

[@watersstanton]

Yes, interesting possibilty.

[@brian.7966]

first :)