Best Random Wire Antenna Lengths ~ 06-02-2021
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- čas přidán 26. 06. 2024
- Webiste- udel.edu/~mm/ham/randomWire/
& udel.edu/~mm/ham/
Presenter- Mike Markowski, AB3AP
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I am 80 yrs young and loving ham radio
Nice explanation, NW1L
First time Ham at age 74! I took all three tests at one sitting and am now AI7MY. I have gone to your web page many times as I have used several different end feds since becoming a Ham bot for base station and SOTA. Where as now my base station is set up on a fan dipole, I still use end feds in the field and have been successful them. My problem was RFI in the shack when used as a base station antenna. I put in various chokes into feed line at various location but could never fully get rid of it. That was why I went to a fan dipole. However, the receiving and transmitting performance of the end feds were very good. Your website really helped me.
Excellent, I learned a lot today just by watching this video, thanks
First time ham at 67!!! God is good!!!
Good video Mike - K7AOZ here. Since I don't have MatLab nor do C / C++ , I rewrote your code into Python 2.7 with great success. Thank you for the original work. 73
I haven't seen a slide rule used in anger since 1967.
Thanks for sharing!
First time HAM at age 58!!
My XYL became a new ham at 77 two weeks ago. She took and passed both Tech and General. She wants to do POTA. I’m trying to make her an antenna
I am talking about maybe dipoles
Name is Herb Abegg
Nice video
Great learning video! I am not yet a Ham, will take test in about a month. I have listened for a few months, and love to make my own antennas. I have made 4 so far. Two are end fed, a 66' Inverted V, it receives very well. I experimented with counterpoise and found a ground worked better for noise reduction. I use a 9:1 Balun and a 1:1 UnUn to prevent any RF into my radio room. My next found 135' worked even better, although it is only 27' right now. It receives better and is quieter. The height of the Inverted V is 37' and the height is a great equalizer. I hope to raise the EFHW 135' soon. Also hope to be transmitting soon as well.
Once you add a counterpoise it's specifically and emphatically no longer an end-fed. At best it becomes another OCF variant. The evolution of traps in line makes more sense in-terms of pure end-fed and mitigating the various feedline as counterpoise/stray RF component that has to be mitigated otherwise.
Looks like 80ft is a good length for an EFRW.
Don't need 8 minutes of bio for a 40 minute presentation
How about using ladder line
The only calculation I did when I took the UK ham exam back in 1969 was 468/f!
looks like the w3edp is a .64 wave about in length on the antenna and 1/8 on the counterpoise!
I volunteer local search and rescue I have been using 40 meter NVIS and had good luck with 100ft out of an icom AH4 random wire tuner and I am wondering what the optimum length for 7100.0 some calculations put half wave near 33ft
Just wondering what happens if I go shorter or longer and Is there a sweet spot.
Mobile set up so it goes up and comes down each time.
good discussion. I hope you will continue to go into practical construction and radiation pattern. I am running a 135' end fed, and considering adding a second antenna to cover the globe.
What is the length of a random length for an end fed antenna?
I have heard about these lengths to avoid…. What happens if we are close to or at those undesired lengths?
I have space around my house to put up a dipole, each leg being a maximum of 12'. What band(s) should I expect to receive??
Thank you!
12' is about 4m, so two arms is 8m long. Since 8m is the half-wavelength, it will work on the non-existent 16m band. But you're getting close to 17m band.
Hold up
Random Wire Lengths ?
If there are best lengths?
Where the random?
If it has a best length it sort of no more is random
Random implies you were on a deserted island and just found a random wire
and had no way to measure
AH
But no worries
I doubtful to find a random tranceiver to go along with your rando wire or anything else
Perhaps this just a bad dream
Quit after 7 minutes