Switching Parts of an Antenna In and Out (
Вставка
- Опубліковано 21 тра 2024
- Andrew wants to know how to create or use an Active Trap. Is it worth it to have a digital circuit or a singular, multi-band antenna? Watch to find out!
Subscribe: / davecasler
Edited by Teagan Kulbeth
Videographed by Aidan Jakeman
#amateur radio
#ham radio
#ke0og
#dave casler
#ham radio answers
#antenna
To learn more about me, visit: dcasler.com
To support my channel financially, visit: dcasler.com/support (offers several options)
To pose an Ask Dave question, email to askdave@arrl.org. Feel free to include pictures or drawings to help clarify. I may answer your question directly, via an Ask Dave video, or in my monthly column "Ask Dave" in QST.
Theme music is "Sour Tennessee Red," by John Deley and the 41 Players, courtesy UA-cam Music Library. You can listen to the entire song here: • Sour Tennessee Red - J...
I use drawings from OpenClipArt.org, including the "walking man"
Thanks to my sweet wife, Loretta, KBØVWW, for both audio and video assistance! (Her website is www.aldea-art.com.)
My primary website: www.dcasler.com
My publishing website: www.mtsneffelspress.com, where you can find my fantasy and science fiction books.
My Amazon author page, which lists my print and Kindle books: www.amazon.com/-/e/B00471I0Q4. - Наука та технологія
Good Video Dave… To me it makes more sense to pick 2/3 bands you like to operate on and put up 2/3 monoband antennas and switch them at the ground. … wire antennas are cheap and easy, but the fan dipole idea is great too…
An EFHW for most bands is the easiest solution. For the others a long wire with a remote ATU. If you want to switch different sizes or verticals, open frame power relays can be remote controled in the shack. BTW, they also work great with ladder line and even coax if careful.
Thanks!
One idea I have been toying-with is to use air switches, like the ones used for hot tubs to avoid electrocution hazards, In particular, I want to have a 40 meter delta loop that can have a section of wire opposite the feed point that can be isolated, creating a 80 meter halo dipole.
Excellent explanation. Thank you. So, for now, keep it simple!! 73, Mike.
You could try, instead of a relay, a mechanical switch (rotary for example) controlled with a servo or similar mechanism that needs power only to change the switch position (off / on).
another excellent video. I have a question for you, "Is it possible to make a 10m yagi?"
Definitely possible! I have built them from aluminum tubing but a cheap and easy way is to use two wire dipoles parallel to each other . One is fed with coax and the other is just a halfwave piece of wire. It can be either the reflector or director while the dipole with the coax is the driven element. The spacers can be thin wood pieces. Spacing varies depending on if you want a director or reflector. Spacing is about 4 feet more or less. Typically directors are shorter and reflectors are longer but not necessarily. Two dipoles the same length can be used and varying the spacing can change the parasitic element from a director to reflector! It can also have gain in both directions! It is possible to get spacing just right so it is a very good match to 50 ohm coax and work with good gain. The ARRL antenna books have info and curves showing how Yagis work. I built several over the years for 20, 15 and 10 meters. By adjusting the tension in the supporting ropes it can be made to hang perfectly flat even with the coax hanging down.
fan dipoles - no switching that way