We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: The definitive end-fed dipole discussion.  (Read 1072 times)

Offline Beerus Maximus

  • Administrator
  • DX Legend
  • *****
  • Posts: 1137
  • Boston, Massachusetts
  • hold my beer and watch this
    • View Profile
    • Beerus' 30 Below Site
    • Email
The definitive end-fed dipole discussion.
« on: February 21, 2018, 1713 UTC »
I feel it is important to clear the air about a subject that has been bandied about lately on these here forums. This is regarding the end-fed dipole.

I am the inventor of the end-fed dipole. I have updated my signature (below) to reflect this. Any other claims to the discovery of the end-fed dipole will be vigorously challenged.

There will be a book. But for now, I would like to provide a simple schematic for those who may be interested in building my antenna:

-----------------------------------------------------  <--- radiating element
|
|
|  <--- feedline
|

Should you have any questions, I am here to answer them.
# Genetically engineered sentient sausage & undisputed inventor of the end-fed dipole
# Listening from Boston's North Shore
# KiwiSDR, NetSDR, RSP2, Airspy HF+, TS-590, IC-7410
# eQSL to beerusmaximus@gmail.com

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 23075
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
Re: The definitive end-fed dipole discussion.
« Reply #1 on: February 21, 2018, 1816 UTC »
I have many questions:

How long should the feedline be?

Which is better, RG-58 or RG-59? (trick question)

What gauge wire should be used for the radiating element?

Will using oxygen free copper speaker wire for the radiating element allow me to hear WABC in the Mt Kisco A&P?

Is it true that wrapping 666 turns of the feedline around a stack of $20 bills will attenuate all Brother Stair transmissions?
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline Josh

  • DX Legend
  • ******
  • Posts: 3016
    • View Profile
Re: The definitive end-fed dipole discussion.
« Reply #2 on: February 21, 2018, 1914 UTC »
If one were so churlish as to extend the radiator length another quarter, it becomes.......... a tripole.
Conveniently located near Vincennes Indiana.

Offline Beerus Maximus

  • Administrator
  • DX Legend
  • *****
  • Posts: 1137
  • Boston, Massachusetts
  • hold my beer and watch this
    • View Profile
    • Beerus' 30 Below Site
    • Email
Re: The definitive end-fed dipole discussion.
« Reply #3 on: February 22, 2018, 0200 UTC »
Quote
How long should the feedline be?

Roughly, it should be equivalent to the length of a slice of bacon, multiplied by as many as you consume in six months, and then again multiplied by the average of your front and rear tire tread depths as a decimal.

Quote
Which is better, RG-58 or RG-59? (trick question)

I always start any discussion about coaxial feed lines with the recommendation to solder the center conductor to the braid as close to the receiver or transmitter as possible. This almost always eliminates significant variation in coaxial feed line performance. Thus, I buy the cheapest coaxial cable I can find.

Quote
Will using oxygen free copper speaker wire for the radiating element allow me to hear WABC in the Mt Kisco A&P?

Using oxygen free copper wire introduces the risk of the bends; I never recommend it without proper decompression to stabilize the ambient pressure inside the insulation.

Quote
Is it true that wrapping 666 turns of the feedline around a stack of $20 bills will attenuate all Brother Stair transmissions?

This depends on the dollar currency in question; Canadian versus American dollars have a very high variation in capacitance which can significantly alter the attenuation properties of the filter you reference.
# Genetically engineered sentient sausage & undisputed inventor of the end-fed dipole
# Listening from Boston's North Shore
# KiwiSDR, NetSDR, RSP2, Airspy HF+, TS-590, IC-7410
# eQSL to beerusmaximus@gmail.com

Offline Fansome

  • DX Legend
  • ******
  • Posts: 1426
    • View Profile
    • Email
Re: The definitive end-fed dipole discussion.
« Reply #4 on: February 22, 2018, 0209 UTC »
Personally, I've always preferred the magnetic monopole antenna. It will become especially useful during the upcoming period when the earth's magnetic field reverses.

If one were so churlish as to extend the radiator length another quarter, it becomes.......... a tripole.


Offline Pigmeat

  • DX Legend
  • ******
  • Posts: 4092
    • View Profile
Re: The definitive end-fed dipole discussion.
« Reply #5 on: February 22, 2018, 0244 UTC »
Quote
How long should the feedline be?

Roughly, it should be equivalent to the length of a slice of bacon, multiplied by as many as you consume in six months, and then again multiplied by the average of your front and rear tire tread depths as a decimal.

Quote
Which is better, RG-58 or RG-59? (trick question)

I always start any discussion about coaxial feed lines with the recommendation to solder the center conductor to the braid as close to the receiver or transmitter as possible. This almost always eliminates significant variation in coaxial feed line performance. Thus, I buy the cheapest coaxial cable I can find.

Quote
Will using oxygen free copper speaker wire for the radiating element allow me to hear WABC in the Mt Kisco A&P?

Using oxygen free copper wire introduces the risk of the bends; I never recommend it without proper decompression to stabilize the ambient pressure inside the insulation.

Quote
Is it true that wrapping 666 turns of the feedline around a stack of $20 bills will attenuate all Brother Stair transmissions?

This depends on the dollar currency in question; Canadian versus American dollars have a very high variation in capacitance which can significantly alter the attenuation properties of the filter you reference.

I like the way you think. None of that pi in the sky stuff like Al.

Offline Josh

  • DX Legend
  • ******
  • Posts: 3016
    • View Profile
Re: The definitive end-fed dipole discussion.
« Reply #6 on: February 22, 2018, 1737 UTC »
Personally, I've always preferred the magnetic monopole antenna. It will become especially useful during the upcoming period when the earth's magnetic field reverses.

If one were so churlish as to extend the radiator length another quarter, it becomes.......... a tripole.

First they came for the warmers.
Then they came for the reversers.
Conveniently located near Vincennes Indiana.

Offline skeezix

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 3537
  • Minneapolis, MN
  • What does 'RNO stand for?
    • View Profile
Re: The definitive end-fed dipole discussion.
« Reply #7 on: February 25, 2018, 0151 UTC »
What is the recommended method procedure for super-cooling the element to provide for faster transmission?

Does this support DC transmission?
Minneapolis, MN

Offline Pigmeat

  • DX Legend
  • ******
  • Posts: 4092
    • View Profile
Re: The definitive end-fed dipole discussion.
« Reply #8 on: February 28, 2018, 1750 UTC »
What is the recommended method procedure for super-cooling the element to provide for faster transmission?

Does this support DC transmission?

DC to Daylight, no sissy filters to impede the RF waves.

Putting the radiator in a reinforced hose filled with liquid oxygen does the trick, but if you're fresh out, use what you've got on hand, butane, freon, etc...

Stand behind something sturdy and non-flammable when you give it the juice and good luck!

Offline Kage

  • Jr. Member
  • **
  • Posts: 73
  • US
  • Modulating Madness
    • View Profile
    • The Free Radio Forum
    • Email
Re: The definitive end-fed dipole discussion.
« Reply #9 on: February 28, 2018, 2220 UTC »
Where do I install the tophat and monocle to focus the beam width toward the hemorrosphere layer? 
I'm not saying aliens are in the radio, but aliens definitely are in the radio.
The Free Radio Forum