Impedance and the Height of an Antenna (

[@haroldbleemel8537]

Dave, you sound like you've been ill. Hopefully you're beginning to feel better if that's the case. 73!

[@Soupie62]

This is a great video. When it comes to wires high in the air, you have to ask: what about the tower? A steel tower is going to interact differently to (for example) a wooden pole.

[@jerrym1183]

For 40 meters, a resonant square horizontal one wavelength approx 144 ft around and up in the air about 18-20 feet, and with a matching horizontal loop underneath about 160 feet around as a reflector, is one "smoking" NVIS cloud burner beaming straight up, and matches beautifully to 50 ohm coax... Is Great out to 1000 miles. And also is super quiet, it is so horizontally polarised it really nulls out out the near-by man-made noise fantastic as well...

[@BusDriverRFI]

If you ever take a math class with limits, you'll understand the usefulness of limits and how the free space values are used so we can better analyze the antenna in our normal environment. Your local junior college should have classes in calculus 1 that will explain it.

[@Ben--David]

I could get up to 600 miles away when I was NVIS on multiband EFHW 10-40M. But I am less than 1,000 feet from the ocean. When I put up a center mast to make it an inverted V, I messed up and used stainless steel guy wires instead of ropes, which put me down to a single band 20M, but on 20M I am clean and clear up to 2,000 miles away so far, had a report from 1,800 miles that said I was 20 over 9. So, I am not changing anything. I have a vertical antenna for 6M & 10M and another for 70cm and 2M. With the awesome repeaters in South Texas, I can hit hundreds of miles on 2M VHF and 70cm UHF. So I am most limited on 6M VHF.

[@Siskiyous6]

If I lived closer, I would help you get a taller mast up. But I have my 144 foot doublet up around 40-45 feet, and with lots of interfering objects around, but it really is a great 80M regional antenna. While limited on SSB, it reaches the ends of the earth with modern digital modes on all the bands.

[@TheTim16964]

Dave, as I understand it. An antenna with a thick diameter is a broader antenna. Is there a point of diminishing return to this? For instance, if i were to make two antennas, one out of wire and one out of 6" pipe, what would be the difference in frequency range with an acceptable SWR?

[@Siskiyous6]

I would think the only Ham band a 6 inch pipe antenna could have trouble on would be 80M.

[@kristhompson8112]

Take care of yourself Dave , I worry ....

[@z3r0c00l2]

So the higher the antenna the higher the impedance?