Questions tagged [vertical-antenna]

Use this tag for questions related to vertical antennas, the construction, characteristics and performance.

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4 votes
1 answer
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What is the radiation pattern and feedpoint resistance of a raised feed point vertical?

If you put a vertical 1/4 wavelength antenna on a pole of about 15 feet and tie the base of the pole to a massive grid of radials and the ground itself how does it affect the radiation pattern and the ...
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2 votes
1 answer
54 views

cut or lengthen to reduce swr on vertical wire antenna

Have tried measuring antenna wire using formula 234/frequency for 1/4 wave vertical but this gives high swr. How do I lower swr on a wire vertical antenna. Do I Cut or Add? wire'
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2 votes
3 answers
181 views

Why does an HF "monopole" need dozens and dozens of radials while a VHF/UHF "ground plane" antenna only needs four?

It's a bit counter-intuitive that for an HF vertical antenna (such as a quarter wave monopole) the best advice is to put as many radials and as close to the proper length as possible. The typical VHF/...
3 votes
1 answer
97 views

Parameters needed to calculate inductor value to achieve proper phase delay?

I'm thinking about trying a coil in my collinear 5/8λ antenna, instead of the 3/8λ phasing delay line between the lower and upper elements pictured below. I figure that a coil with a certain ...
4 votes
2 answers
207 views

Can I use my CB mobile antenna with a 10 meter radio also?

I have a mobile mounted CB antenna that has an SWR of 1.5 on channel 20. Is it possible to use it with a 10 meter radio? I do not have enough room on my car for an additional antenna, so if it is ...
3 votes
3 answers
262 views

Antenna options for a small urban garden

I've narrowed down my antenna options to fit a small urban garden. It's tough, space is tight and a neighbour three doors down reports everything I do to the council so I'm routinely inspected for ...
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2 votes
3 answers
132 views

Ferrite unun transformer to match antenna resistance loads of <50Ω?

For LF/MF (2200m/630m), I am interested in the situation of a vertical antenna with capacitance hat top-loading, where the vertical antenna is VERY short compared to wavelength, and the antenna is ...
2 votes
3 answers
365 views

radials for 6 band Hustler vertical

I don't have room for quarter length radials for my Hustler 6 band vertical (10through 80 meters). Can I use 20 foot radials? If so, how many? The hustler is a Hustler 6-BTV 6 band HF vertical ...
3 votes
1 answer
112 views

Phasing stub length for colinear 5/8λ?

I've been designing a "Super J-Pole" for 10M in MMANA-GAL, but I'm designing it having two 5/8λ sections. However, I came across this picture: Various J-Poles types diagram indicating the ...
1 vote
1 answer
124 views

Using Decoupling Stubs to Allow a Vertical Yagi to be Mounted on a Metal Pole

A while a go i asked a couple of questions on this site about mounting a vertical yagi antenna on a metal pole. One of the answers given to the first question talks about using decoupling stubs to ...
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2 votes
3 answers
331 views

Why half-wave dipole is the most efficient one in comparison to other electrical lengths of that antenna?

I have a problem on the understanding of a half-wavelength antenna. Namely, why is the half-wave antenna has a highest power emission. Considering Far Field factor F($\theta$), which is known from the ...
3 votes
2 answers
352 views

Mounting a vertical antenna on a fiberglass mast

I have a multiband SE-X80 HF vertical antenna which works ok from 20 meters to 10 meters with a tuner. It is attached to the railings of my apartment balcony at the moment. This is the antenna : https:...
2 votes
1 answer
45 views

How Accurately Does NEC-based Antenna Software Calculate Vertical Monopole Antenna System Radiation Efficiency for "Far-Field" (Only) Conditions?

A common belief among amateur radio operators is that the radiation efficiency of a vertical monopole driven against the Earth is much less than that of an elevated, horizontal dipole of the same ...
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4 votes
1 answer
315 views

How does the material of a fishing-pole mast affect antenna performance?

I'm a newly-licenced ham and currently starting out with HF. My home doesn't allow for a permanent setup. I can therefore only operate portable from parks and such, with limited TX power (my rig goes ...
4 votes
3 answers
249 views

RF ground confusion

I'm a bit confused by RF grounding. Let's take a HF 1/4 wave vertical antenna for example. When current flows through the centre of the coax to the antenna, my understanding is that the current then ...
3 votes
0 answers
61 views

Is this author correct about using a λ/2 of wire for a coil to get the proper delay on a λ/2 collinear antenna?

Is this author correct about using a λ/2 of wire for a coil to get the proper delay on a λ/2 collinear antenna? Improving the Super-J August 5, 2012 by John S. Huggins I agree with him that there has ...
5 votes
5 answers
979 views

Grounding a vertical antenna from a balcony

I have a multiband vertical antenna mounted onto the railings of my balcony apartment high up on the 6th floor of an apartment building. The antenna is not grounded. This antenna comes without radials....
5 votes
2 answers
353 views

Can coax be run through the center of a radiating element without currents being induced on the coax shield?

I run a λ/2 vertical dipole for 20M that's fed to a 1.5:1 balun at its center with coax that is perpendicular to the dipole (parallel to the ground), for about 30 feet before it comes down to the ...
3 votes
1 answer
307 views

Can I use electrical ground / earth as my RF ground?

I live on a high floor in an apartment block and have a radial-free multi-band vertical antenna attached to my terrace railing. This is the antenna : https://www.thunderpole.co.uk/amateur-radio-...
2 votes
2 answers
929 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 votes
2 answers
229 views

Vertical antenna with feedpoint below ground plane?

What happens when a groundplane antenna's vertical element, bottom feedpoint, and/or bottom loading coil move down and encroach into the area below the plane formed by its own perpendicular elevated ...
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1 vote
0 answers
78 views

Avoiding radio damage with closely spaced VHF/UHF antennas

I've mostly been using a discone in the attic so far, but now I want to get proper antennas up for 2m/70cm and gmrs. I'll probably get common commercial vertical antennas. I'm not sure how much I ...
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1 vote
1 answer
177 views

Unable to tune 20m vertical with trio of Hustler resonators on top

I just built a homebrew antenna that consists of a full-length quarter-wave vertical sized for 20m, with a "top hat" consisting of a Hustler VP-1 and trio of Hustler mobile resonators (RM-...
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2 votes
2 answers
151 views

antenna element with "doubled up" nested aluminum rods for added stiffness

I'm building a full-size quarter-wave 20m vertical antenna (approx. 18 feet long, plus a trio of Hustler mobile resonators at the top to add 30, 40, and 80 meters). To make the top 12-14 feet stiff ...
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5 votes
3 answers
406 views

What do you call antenna that combines multiple Hustler resonators (using a VP-1) above a shared mast?

I know that a Hustler MO-3 54" mast with something like a RM-20S resonator on top is officially an example of a center-loaded quarter-wave vertical... ... but Hustler also allows you to mount ...
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3 votes
3 answers
300 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 ...
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-1 votes
1 answer
69 views

Using inverted Yagi antennas to gather and cohere RF from the sky

Imagine a group of eight or more vertical masts. On each mast is a Yagi antenna pointed upward toward the sky. The elements are inverted with the idea being that the incoherent RF coming down is given ...
1 vote
2 answers
312 views

Troubleshooting 5BTV antenna

I have a Hustler 5BTV antenna i resurrected after a previous monopole succumbed to birds. It is giving me a world of trouble trying to get it tuned for resonance. For those not familiar with the ...
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0 votes
0 answers
171 views

How to stabilize an antenna

I have an antenna on a building. It is made of steel and is about 10ft long. It wobbles a bit in high winds. It is not going to do a Tacoma Narrows but it is a bit annoying. Can I tie stainless steel ...
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4 votes
3 answers
878 views

Is the Boom Strictly Necessary in a Vertical Dipole?

I'm planning to build a vertical dipole for 4m and a club member pointed out that my design needs to allow for a boom that should be at least a 1/4 wave long. Why does a vertical dipole need a boom ...
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5 votes
1 answer
502 views

How does this W6NBC "derivative of the classical slot antenna" work?

Via the https://ham.stackexchange.com/a/9883/1362 answer regarding a slot antenna for a 2m mobile application, I was introduced to this (pdf) interesting antenna design: The designer John Portune (...
0 votes
0 answers
95 views

what frequencies is this antenna cut for?

I just bought a magnet-mount whip antenna at a garage sale. It has no brand markings anywhere on it. it is 32" long overall but is broken up into three segments by what appear to be two small ...
1 vote
2 answers
194 views

Does Improving Earth Conductivity Near a Buried Ground Rod Improve Antenna System Performance?

The suggestion has been made on various ham-related websites that improving the conductivity of the Earth around a ground rod produces a worthwhile improvement in the e-m radiation from a vertical ...
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1 vote
4 answers
406 views

Why are many ground radials preferable to a single ground stake buried 1m deep?

Surely a 1m copper stake provides better ground connectivity for a vertical dipole?
1 vote
2 answers
145 views

How Does the Propagation of H-pol E-M Fields Compare to That of V-pol E-M Fields (other things equal)?

A rather popular belief on this topic is that h-pol is superior to v-pol. Probably that is traceable to published "far-field" patterns over a lossy ground plane generated by Method of ...
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2 votes
1 answer
100 views

What Are the Properties of 43' Vertical Monopoles Used as Multiband Radiators?

43' vertical monopoles sometimes are used with an auto-tuner at their input as radiators in the ham bands from 40m through 10m, but are any performance compromises required to do that?
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1 vote
2 answers
1k views

Is a 1/4 wave vertical actually better than inverted L on 160m?

Surprisingly, I am unable to find much info comparing these two antennas. Essentially, they are the same except the one is shorter and top loaded with one wire. Does anyone have any performance data ...
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2 votes
0 answers
230 views

Vertical antenna near power and cable lines

I have a 40M vertical on top of my roof. When I transmit at 100W, my internet drops. My neighbor's internet too (different cable company). At 50W it seems to be OK. As an expermient, I used a smaller ...
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1 vote
3 answers
158 views

Need antenna for mobile mag-mount LPFM broadcast 88.3 MHz

I am doing some temporary FM broadcasting for car events such as COVID-safe car parades and drive-in movies. The terrain is horrible, urban areas with lots of buildings. The cars snake around a city, ...
2 votes
1 answer
2k views

how does this collinear antenna work?

I was looking for a cheap and easy to build 2M/70cm vertical. I found this: http://vk2zoi.com/articles/dual-band-high-gain-flower-pot/ Here are the plans to build it: But I don't really understand ...
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3 votes
5 answers
280 views

Can I use a 1/4 wave decoupling stub to enable mounting of a vertical yagi on a metal pole?

My understanding is that the ground plane radials used on, for example, a free standing 5/8 wave 10 m vertical antenna mounted on a metal pole, are actually 1/4 wave length decoupling stubs, the ...
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0 votes
1 answer
60 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.
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2 votes
1 answer
164 views

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

Their performance differences may be less than sometimes expected.
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10 votes
3 answers
2k views

Can a 1:1 transformer be used as a protection from static electricity?

It's well-known that under certain conditions verticals and dipoles can gather static charge, which is a common reason of transceiver damage. There are several ways to solve this issue. Some hams ...
2 votes
1 answer
260 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 ...
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1 vote
1 answer
319 views

Vertical Hustler - do I need any radials?

I'm planning on installing a Hustler 4-BTV vertical by the house. There's already a 12 ft. steel pole mounted in cement, so I'm going to mount it on that pole about 10 feet up (sort of small mini ...
1 vote
2 answers
162 views

Vertical antenna

I'm installing a vertical antenna in back yard. About 20 feet in height and using 1 counterpoise wire 16 feet for 20 meters. Does installing two or more counterpoise wires help?
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3 votes
1 answer
156 views

Do Far-Field Radiation Patterns/Gains of NEC Software Accurately and Always Show the E-M Fields "Launched" by Vertical Monopoles?

Judging from posts on the Internet, this belief commonly is considered to be valid. But what is the correct answer?
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1 vote
1 answer
253 views

Grounding for an upper floor shack

My shack is on the second floor, 4m from the ground. My main antenna is a base loaded vertical, using the metal roof (10x6m) as a ground plane. When I operate in 20 and 40 meters, it's pretty ...
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3 votes
1 answer
101 views

What sort of antenna would use a bicone or lozenge-like arrangement of vertical wires?

In another QA here, there's a picture of an antenna I identified as a "discone": What are these antennas used for? One commenter noticed that antenna was actually a "Discone, but no disc, just the ...