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Questions tagged [vertical-antenna]

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

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23 votes
2 answers
19k views

What makes a 5/8 wavelength vertical desirable?

An ordinary 1/4 wavelength vertical is smaller and resonant without any loading coil or matching network. What's the advantage to a 5/8 wavelength vertical? Why 5/8 in particular, and not something ...
Phil Frost - W8II's user avatar
17 votes
8 answers
39k views

Should I chose a vertical or a horizontal HF antenna?

If I only have the budget for one HF antenna, should I chose a vertical or a horizontal antenna?
Timtech's user avatar
  • 2,336
11 votes
2 answers
5k views

How to reduce RF in the shack when using vertical HF antenna (no radials)

What can be done to reduce RF in the shack (riding back along the coax) when using a vertical 10M antenna (without radials due to space constraints)? The antenna is an IMax-2000 at 32' elevation (20' ...
Ron J. KD2EQS's user avatar
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 ...
Aleksander Alekseev - R2AUK's user avatar
9 votes
7 answers
16k 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 ...
Kevin Reid AG6YO's user avatar
  • 24.6k
9 votes
2 answers
2k views

Marine VHF whip antennae - what are they?

For marine VHF (156~162 MHz), the most commonly used antenna is a 1/2-wave dipole or a collinear array in the form of a fibreglass rod. Collinear arrays are used to increase gain in some antennas. ...
user5314's user avatar
8 votes
5 answers
7k views

Does mounting a ground plane antenna upside down change the takeoff angle?

A typical gain pattern for a quarter wave ground plane antenna is: Image from a similar question and see watermark. For a situation where the signals of interest are below the antenna in elevation (...
hazzey's user avatar
  • 229
8 votes
3 answers
2k views

Vertical antenna on HF?

What are some of the advantages and disadvantages of using a vertical antenna on high frequency? Are there any better antenna types that I should use?
Timtech's user avatar
  • 2,336
8 votes
2 answers
18k views

calculating all specifics for a 5/8 antenna

So, I've built a couple 1/4λ ground plane antennas for Airband and Marine band. I don't transmit, I'm just listening, etc. So, constructing ground plane antennas with the radials and getting the ...
polemon's user avatar
  • 277
7 votes
7 answers
10k views

What is the attraction of vertical antennas for HF?

I understand that MW broadcast stations use vertical antennas because that polarization works much better for groundwave propagation. But in amateur radio, I would assume the focus for communications ...
natevw - AF7TB's user avatar
7 votes
2 answers
2k views

Practical 80m vertical wire antennas without radials?

We'd like to install an antenna for 80m at our club/contest station. Our club, OH2K, is housed at a school, and we can't fill the roof with a radial mesh. The roof is not metallic itself, either. We ...
oh7lzb's user avatar
  • 2,391
6 votes
2 answers
5k views

Tuning/trimming a ground plane antenna

I've built a ground plane antenna with a 19.5" vertical and 4 20" radials. Currently, at 147.135 MHz my SWR is 3:1, clearly not ideal (and even bad for the transmitter!). I'm reluctant to start ...
David Hoelzer's user avatar
  • 1,053
6 votes
5 answers
2k 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....
Engineer999's user avatar
6 votes
2 answers
968 views

Multiband vertical antenna not working as expected

I built a vertical out of a 5M aluminium pipe. It tunes fine (and wide!) on 20M. I decided to add a loading coil to operate it on 40M, and it also worked fine, albeit not so wide. While I was at it, I ...
hjf's user avatar
  • 1,199
6 votes
1 answer
1k 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 ...
Richard Fry's user avatar
  • 2,922
6 votes
2 answers
5k views

Base vs center loading a vertical antenna

I currently use a homebrew 40/60/80m vertical consisting of a 5M aluminium tube with a multi tapped coil at the base. The ground plane is the metal roof at my house, and the antenna is not centered in ...
hjf's user avatar
  • 1,199
5 votes
4 answers
2k views

Can a vertical antenna be used for NVIS?

I know that verticals are normally chosen for their low angles of radiation without obscene heights, but I'm not especially interested in DX and am primarily looking for local coverage via NVIS. I've ...
William's user avatar
  • 803
5 votes
3 answers
3k views

What is the proper way to electrically wire in a loading coil to a vertical antenna?

I am trying to put together a vertical pole style antenna with a loading coil housed at the base using a plan very similar to the one described in this ARRL article. I am trying to understand how to ...
SandPiper's user avatar
  • 777
5 votes
3 answers
3k views

Size of ground plane disk for vertical antennas?

I’m looking for information about the diameter of a ground plane disk that I can use with a regular car radio and car type antennas in my home. DIY would be best, or any other ideas for a antenna that ...
Gregory DeHart's user avatar
5 votes
2 answers
517 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 ...
Louis Seaman's user avatar
  • 1,025
5 votes
1 answer
8k 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 ...
MarqTwine's user avatar
  • 191
5 votes
1 answer
781 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 (...
natevw - AF7TB's user avatar
5 votes
1 answer
2k views

How to calculate or estimate surface area of required ground plane for a mobile antenna?

I don't have conditions for installation of a fixed 2 m/70 cm antenna at home, so I'm thinking of using a mobile magnetically mounted antenna on a conductive plate instead. So my question is: What ...
AndrejaKo's user avatar
  • 2,893
5 votes
1 answer
370 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 ...
Louis Seaman's user avatar
  • 1,025
5 votes
3 answers
783 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 ...
Bitbang3r's user avatar
  • 401
5 votes
1 answer
346 views

What is this vertical antenna with radials pointing up

I work next to "Koninklijk Marine Kadettenkorps Afdeling Oostende" (Royal Marine Cadet Corps Ostend). They have an antenna that I've been wondering about for years now: It is a vertical ...
Dieter Vansteenwegen's user avatar
4 votes
3 answers
1k 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 ...
ON5MF Jurgen's user avatar
4 votes
2 answers
5k 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 ...
User5754448's user avatar
4 votes
3 answers
2k 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 ...
Buck8pe's user avatar
  • 989
4 votes
2 answers
9k views

2 Meter horizontal or vertical dipole polarization?

When should I use one polarization over the other on 2 meters? I've looked at the radiation patterns for horizontal dipole and seen how it changes based on mounting height. I haven't been able to ...
KM4NTK's user avatar
  • 135
4 votes
1 answer
905 views

How Does the Performance of Elevated Radials Differ from That of Buried Radials?

NEC4.2 provides some information about this topic that may be of interest to some readers.
Richard Fry's user avatar
  • 2,922
4 votes
2 answers
2k views

Can I use a 1:1 current balun to feed a 1/4λ vertical?

I have an LDG RBA-1:1 current balun, and I was wondering if it behaves as a common-mode choke that I can use for a ground-mounted quarter wave vertical w/ 16 radials. The other choice I have is a 4:...
Rimio's user avatar
  • 137
4 votes
3 answers
667 views

Antenna suggestions for 160m band in smallish yard?

I have a decent-sized but not huge yard (roughly 50x100' / 15x30m) and I'd like to get on the 160-metre band. It's hard enough to get out on this band so I'm looking to do something reasonably ...
Jim MacKenzie VE5EV's user avatar
4 votes
1 answer
351 views

How Does Earth Conductivity Affect the "Takeoff Angle" of a Vertical Monopole?

NEC4.2 gives some insight into this ...
Richard Fry's user avatar
  • 2,922
4 votes
2 answers
1k 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 ...
diodes123's user avatar
4 votes
2 answers
773 views

How should I mount a mobile antenna on a vehicle with a non-conductive body?

I would like to mount a self tuning antenna, ATAS-120, matched with the FT-857D transceiver. I would like to make this pair function on an ARGO 8x8 amphibious vehicle with a polyethylene body. There ...
scott's user avatar
  • 41
4 votes
2 answers
5k 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 ...
Adam Davis's user avatar
  • 12.1k
4 votes
1 answer
132 views

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 ...
david's user avatar
  • 141
4 votes
1 answer
920 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 ...
Ivan R2AZR's user avatar
4 votes
2 answers
2k views

Does antenna width/shape affect resonant frequency like length does?

I was wondering if I made an antenna from a Rohn 25G tower, would it have the same resonant frequency as a pole of the same height (assuming guys are insulated)? Also with the Rohn antenna, the waves ...
Synaps3's user avatar
  • 425
4 votes
1 answer
2k views

Antenna Tripod for a vertical antenna

I'm considering buying a vertical HF antenna (Such as the Cushcraft R8), and a tripod antenna stand, such as the MFJ-1918, and setting it up on my back porch when I'm operating (Which won't be all of ...
PearsonArtPhoto's user avatar
4 votes
3 answers
629 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 ...
Engineer999's user avatar
3 votes
5 answers
419 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 ...
Andrew's user avatar
  • 3,683
3 votes
4 answers
3k views

Give vertical antenna directional gain?

So here is a strange thought. If a vertical electrically speaking is a half dipole with the other half as a ground plane to balance out. Perhaps there are ways to make equivalent director and ...
Matthew Wang's user avatar
3 votes
2 answers
816 views

HF Vertical antenna with no radial and loading coil but only ATU for 80m to 10m in a boat

I am new to HF antenna designs. I want to build an antenna for my fishing boat. My question is - if I use an ATU (like the ATU-100) and a 10m aluminium pipe as an antenna and fix it with a mast, will ...
Asif Rahman's user avatar
3 votes
2 answers
934 views

How to establish RF ground for 1/4 wave vertical in apt on 3rd floor (about 35ft above the ground)

I am struggling to understand how to introduce an MFJ-931 artificial RF ground into my current system and am hoping for some help to sort out best practices. Although my use-case seems pretty common, ...
A Bit of Help's user avatar
3 votes
2 answers
3k views

Stabilization of an antenna pole with anchoring cables

I am mounting my first antenna. It is a TRAM 1481 (about 16' height), which will be placed on a 20' pole, on my home's flat roof (about 25' height). To properly stabilize the pole/antenna: - How far ...
KP4MCG's user avatar
  • 217
3 votes
2 answers
3k 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 ...
hotpaw2's user avatar
  • 13.4k
3 votes
2 answers
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 ...
hotpaw2's user avatar
  • 13.4k
3 votes
3 answers
827 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 ...
rcx935's user avatar
  • 411