Questions tagged [radial]

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2answers
149 views

What do radials really do for a vertical antenna?

I have read everything I can find about monopole (vertical antenna) radials, and also watched many YouTube videos that touch on the topic. I see conflicting information about what they do, where a ...
3
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2answers
69 views

Ground plane reflects RF or brings it to ground

I'm still confused with the purpose of a ground plane purpose in an antenna. My understanding is this. If an antenna is perfectly balanced, there will be no common-mode currents going to ground. If an ...
3
votes
3answers
278 views

Is The Lowest Antenna Terminal Feedpoint SWR Always Optimal?

Intuition might lead one to believe that the antenna configuration with the lowest SWR(50) across its input terminals would provide the best radiation efficiency for the antenna system. But is that ...
2
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1answer
74 views

RFI from radials

Helping a friend with his RFI problem. He has a SDR HF radio and Hustler BTV antenna with a toroid choke and about 32-radials. He has vertical bars on his panadaptor around 20 khz apart, mainly on 40M....
3
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3answers
699 views

Ground-Plane radial sizing, is there such thing as too long?

I'm just trying to make sure I understand the theory correctly. I have some triband VHF/UHF/800MHz antennas, I need to mount on a tower so I plan on using a "mobile to base" conversion kit. ...
3
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1answer
132 views

Do the Horizontal Conductors of a Ground Plane Antenna Adequately Decouple Its Feedline?

A NEC4.2 analysis of this configuration may reveal an unexpected truth about this...
0
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1answer
54 views

What Are Some of the Most Important Characteristics Applying to the Radiation of Monopole Antenna Systems?

Such characteristics are described in Answer 1 below, as sourced in a study of antenna engineering textbooks, and by generating NEC4.2 studies.
2
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1answer
51 views

How Do Ground-Mounted Verticals Compare to Elevated Verticals? [duplicate]

Their performance differences may be less than sometimes expected.
2
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1answer
223 views

Which is Better to Use with Vertical Monopoles: Buried Radials or Ground Screens?

Many threads posted on various websites over the years have included statements/beliefs on this subject, but support there for the accuracy of those statements sometimes is minimal. An accurate ...
2
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1answer
122 views

Do Buried Radials for Vertical Monopoles Need to be No Longer than the Monopole Itself?

This is a rather common belief among amateur radio operators, but is it true? A NEC analysis provides some insight on this concept.
0
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1answer
139 views

Vertical Antennas

I have just changed from a ground mounted Vertical antenna , to a MFJ-1796 Vertical antenna, due to not having big enough ground to bury as many verticals as recommended. So far what I have found is ...
3
votes
2answers
169 views

Dielectric Constant of Insulation/RF Permeability

I recently purchased a 500-foot roll of military surplus 14 AWG stranded copper wire at a hamfest for next to nothing . It is Prestolite M13486/1-6 (spec sheet). It has very thick chlorinated ...
1
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1answer
152 views

Hobby Wire for Ground Radials

I'm putting in a radial system for my inverted-L and am wondering if the hobby wire like the kind sold at Hobby Lobby or Home Depot for hanging pictures, which is 22-24 gauge copper or aluminum, would ...
5
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1answer
957 views

Are Elevated Radials Necessary for Elevated, 5/8-wave “Ground-Plane” Antennas?

Currents at the base of an elevated, 5/8-wave, vertical ground-plane (GP) transmit antenna are lower than when that vertical conductor is 1/4-wavelength. Does this mean that the performance of the ...
2
votes
2answers
181 views

Ground radials: Electrical difference between 14 gauge and 18 gauge? Lifespan difference?

I am starting the process of installing a vertical ant (6BTV) and radial ground system. I am ready to buy the wire. I would like to know if there is an electrical difference between 14 gauge and 18 ...
5
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1answer
4k views

Radial length for vertical antennas?

I plan on installing a vertical antenna soon. I expect it to cover from 80 meters to 10 (or perhaps 6). I plan on putting down 32 radials. I am wondering if 16 66' and 16 33' radials will be just ...
3
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2answers
1k views

How low can a vertical dipole be mounted?

An answer to this question suggests that raising a vertical dipole sufficiently can create the effect of a phased array. How about the opposite. How low can a vertical dipole be mounted? Can a ...
3
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2answers
2k views

Using two short mobile HF antennas to make a vertical dipole

Instead of using a metal vehicle roof or multiple radials as the counterpose to a shortened vertical antenna, can one use two of them, one pointed downward to construct a balanced vertical dipole, and ...
4
votes
3answers
595 views

Radials on a vertical, spread out evenly or not?

To have a groundmounted quarter wave vertical with a decent efficiency you need at least 16 radials. So normally you would spread them out on the ground evenly around the base. This would give an ...
9
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7answers
13k views

When and why does the size of a ground plane or radials matter?

Consider these three cases: My understanding is that when building or installing an antenna designed to operate over a ground plane (e.g. a quarter-wave vertical), the size of the ground plane does ...
3
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3answers
2k views

What do you connect antenna Radials to?

I am trying to communicate between two arduino microcontrollers using radio. For this purpose I am building a whip antenna with 4 ¼ wave radials. I've done a bit of reading and have got most of it, ...
13
votes
3answers
9k views

What is the effect of using different number of radials with ground plane antenna

I'm new to electronics and telecommunication at all, I having trouble with understanding the difference between 2, 3 and 4 radials, as I've searched online I've learned that I can use only 1 radial(...
2
votes
1answer
1k views

What are the effects on an ATAS-120A screwdriver antenna with a limited ground plane?

I'm going to be installing an ATAS-120A screwdriver antenna at the corner of a metal roof building, without radials going out over 270 degrees of the plane it's on. Will this significantly change the ...
4
votes
2answers
4k views

Can I ignore the radial elements of a 2m/70cm antenna if it's on a metal roof?

I'm looking for a dual band base station antenna, and find that many of them have short radials around the base. Due to the specifics of my installation, I need to remove them. However, it is being ...