Linked Questions

3
votes
1answer
2k views

3 Band (80-40-20 Meter) Fan Dipole Tuning Question

I built a fan dipole according to the basic instructions in the SRI publication describing the theory and basic design. My questions is about next steps in tuning for the various bands. I am ...
3
votes
3answers
775 views

Unexpected Resonance - Dual-Band Dipole

I tried to make a dual-band (2m/70cm) dipole this morning by following the instructions on this page: http://www.amateurradio.bz/2m-70cm_vertical_dipole_antenna.html, with the rather major significant ...
4
votes
2answers
360 views

Does a dipole require a 1.5:1 balun?

Dipoles ideally have 72 ohms impedance. I know most of the time this isn't what one gets and it can vary a lot. But let's assume we can build this perfect dipole that exhibits this impedance. Why do ...
1
vote
2answers
2k views

How to make a loop antenna for HF?

While researching this answer, I came across information that indicates that a many good Low Frequency/ Very Low Frequency antennas are loops, with high directionality and good overall characteristics....
2
votes
1answer
952 views

Connecting a coaxial cable as feed to a halfwave dipole

I have as assignment to make a half wave dipole antenna, that radiates at 433 MHz. I am trying to figure out how to use a coaxial cable as transmission line. I know that the coaxial cable is ...
3
votes
1answer
604 views

Benefit to remote antenna tuner for end-fed non-resonant antenna?

Does addition of a remote feed-point antenna tuner affect the use of the coax braid as a radiator? If it no longer "radiates" in such a setup, what does? Is a shack or remote tuner better for ...
2
votes
2answers
912 views

Grounding Help - Where To Route My Wires

Here is my situation. My antenna mast is on the opposite side of the house from my ham shack, same with the power service entrance. I have installed ground rods roughly every 16 feet with #6 wire ...
1
vote
2answers
734 views

Multi-part question. correct length of rg-8x coax to connect 2 meter HT to 50 ohm yagi

What it the optimal number of wave lengths of RG-8X coax to connect my Icom IC V80 HT to a 50 ohm Jetstream JTBM270 Yagi (3 elements 2m/5 elements 70cm)? Odd or even number thereof? Will running the ...
4
votes
3answers
479 views

Is RF current always confined to the inner diameter of a braided outer conductor of coaxial cable?

Prompted by a previous question found at Using a balun with a resonant dipole -- an answer there included the following text: "For transmission lines (twin-lead or coax) to not radiate, each ...
2
votes
2answers
291 views

Air conditioner duct as counterpoise?

Many suggestions on the Internet for a "starter" HF long wire, suggest running a wire in the attic. My (South Australian) roof has a 30 degree pitch, and what little space remains contains air ...
0
votes
3answers
194 views

To folded dipole, or not to folded dipole?

I currently operate a 20M half-wave dipole with a balun. It's a little lower than ideal, but it gets me on the air. I've read about folded dipoles. But I've found contradicting information about them....
1
vote
1answer
459 views

Grounding plan for new ham shack - good/bad idea?

I have been researching and trying to plan out how to run the grounding/cables for a new ham radio room that will be in a new cabin being built. Since I am starting with dirt, I should have ...
1
vote
1answer
544 views

How to assemble an antenna (impedance matching methods)

I got the following plans off Martin E. Meserve's website. How do I go about assembling the antenna once I have the elements and boom? What is the impedance of the driven element? Do I need baluns ...
2
votes
2answers
292 views

Measurement Confusion

I am building a simple antenna from this article 7db for 7 bucks. I am confused on the measurements for the antenna: It looks like there are two pieces of 18 inch PVC pipes connected to a T fitting. ...
2
votes
2answers
83 views

Grounding of a portable setup

I am occasionally using an extremely simple shortwave portable setup consisting of a battery, the transceiver, a short coax feedline and a vertical half-wavelength vertical antenna with a transforming ...

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