Radio Amateurs (HAMS) do not Hinder but Serve their Local Communities in the Southern Cape Area!

Image:  Mobile Emergency Communication Station  (Click on image for larger view.)

The title of the article says it all: Radio Amateurs (HAMS) do not Hinder but Serve their Local Communities in the Southern Cape Area! 

Through the years amateur radio operators has wrongly been identified as Citizen Band (CB Radio) operators that in the eyes of the public serve no useful purpose other than chatting to each other on their radios.  This impressions is far from the truth when it comes to amateur radio operators also called HAMS.  There are more than 3 million people World Wide that practices Amateur Radio.

Incidents where neighbors spot a towering antenna or a mast rising above the rooftop has resulted in complaints being send to the local municipal authority in Mossel Bay.  Some view the towers or masts as a concern and an eyesore while others complain that its obstructing their sea view.  Some even go so far as to claim that is its a health and safety risk and also an unnecessary intrusion on the skyline just to talk to one another.  In this day in age why not use a cellphone to talk to your buddies?  Such complaints are on the increase and it has become necessary to address concerns of the general public even though in some cases the radio amateur lived and erected a tower in the neighborhood long before new entrants moved into the area.  Understandably from an aesthetic standpoint, the profound role these masts and antennas play is overlooked from the point of view by the general public as well as uninformed local authorities.

Far from being a mere hobby or a nuisance, amateur radio operators (HAMS) are licensed guardians of emergency communications and render their skillful knowledge and service to the general public and local authorities during disasters, emergencies, community events etc.  This service is provide free of any charges and all expenses is bared by the radio amateurs themselves.  A free service to the benefit of the local authority and the general public whenever our services are needed.  I will later provide more information on the specific services rendered and also proof of such services being provided in the past.

Anchored in rigorous International and National Regulations, the service that radio amateurs provide is a testament to service, innovation and community protection.  Yes, community protection! (See link below for more information)  

Now this article provides an overview into the regulated world of amateur radio, its vital contribution to the Southern Cape Area safety net and the official endorsements that underscore its value, transforming what might seem like a nuisance and backyard operation to some.  In fact this is far from the truth.  Please read on and you will discover how the best hobby in the world is also the beacon of resilience.

A Regulated Service

Amateur Radio is not only a hobby but also renders a service to the local authorities and community when modern communications fail.  Yes modern communications do fail.  The Knysna Fire 2017 is only one instance where modern communications failed.  Amateur Radio is a formally recognized radio communication service under Local and International law. The International Telecommunication Union (ITU), a specialized agency of the United nations, defines the amateur radio service in it's Radio Regulations as "a radio communication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, by duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest."  This definition, enshrined in Article 1.56 of the ITU Radio Regulations, elevates amateur radio beyond a hobby to a structured discipline with global oversight.

In South Africa, this international framework is implemented through the Independent Communications Authority of South Africa (ICASA).  Established under the ICASA Act and the Electronic Communications Act of 2005, ICASA issues amateur radio station licenses only to those who demonstrate technical competence.  Aspiring operators must pass rigorous examinations covering radio theory, regulations and operating procedures.  Licenses are divided into classes:  Class A (for advanced operators) and Class B (for beginners), with restrictions on power output and frequency bands to ensure safe and interference free operations.

Towers and antennas, often the focal point of neighbor disputes are not erected haphazardly.  ICASA's Radio Frequency Spectrum Regulations 2015 mandate compliance with structural safety standards, including engineering assessments to withstand South Africa's variable weather conditions. 

In many instances by-laws of local authorities does not make provision for radio amateur antennas, masts and towers.  When a complaint is lodged the local authority use old and outdated by-laws.  In some instances antennas and towers are described as structures and building plans must be submitted together with a town planner and structural engineer's certification. Written permission must also by obtained from neighbors. Some authorities rely on by laws regarding the installation of TV Antennas which is then used for installation of amateur radio antennas, mast and towers.  Currently there is no distinction in this regard. This is an omission that seriously hampers the great free services provided by amateur radio to their respected communities.

In many cases complaints rely solely on the visual impact of the antennas and tower and not on the service that amateur radio provides to their local communities.  In other instances amateur radio antennas, masts and towers has been erected long before any by law existed that regulates installations. In one instance a radio amateur erected his tower in 2004 and a neighbor only complained about the tower only 14 years later.  

Don't understand me wrong it is not that we are unwilling to comply or work with authorities and the community when putting up towers.  We need to all work together, provide sound input and representations  to establish clear guidelines and by-laws.  The ideal situation would be that amateur radio antennas and towers be recognized  as essential infrastructure rather then illegal  or that it's visual impact is not acceptable to some. 

Amateur Radio is over a century old, with roots tracing back to the late 19th and early 20th centuries. It originated alongside the birth of radio technology itself, with enthusiasts experimenting with wireless telegraphy as early as the 1890s.  Now that we know how old amateur radio is, it is important to look at some services it rendered in the Southern Cape and South Africa throughout the years.  Unfortunately space only allows for a few examples but I am sure those mentioned here will provide a great overview of the service we provide to our local communities, authorities locally and nationally as well as world wide.

Community Service in Action (Internationally, Nationally and Locally)

Before I provide a few incidents let me point out that there are to many instances where amateur radio saved lives by assisting in providing emergency communications when all else failed or when a distress call is received.  I will only provide a few.  Before continuing I would like to mention that radio amateurs does provide a service that entails many different scenarios.  The instances below does not mean that radio amateurs can only assist in the mentioned incidents.  Some might even be surprised to learn that radio amateurs can provide emergency communications in outer space via satellites should the need arise.  Radio Amateurs can "cater" for any eventuality as they do have all the necessary radio equipment and satellites available to do just that.

Image: Mossel Bay Fire Storm  (Click on image for larger view.)

Now herewith a few past and present events that radio amateurs assisted in:  (Click on the links for more information)

• One of the most famous rescue effort took place after the Laingsburg Flood (25 January 1981) and for a week, the only contact between Laingsburg and the rest of the country was via Amateur Radio.
• Harnessing Technology for Early Warning - Local Mossel Bay Radio Amateur participate in the Disaster Mitigation for Sustainable Livelihoods Research Project by the University of Cape Town.
• Mossel Bay Radio Amateurs give wireless support behind the scenes -  Knysna Fire Disaster 2017
• Amateur Radio Mesh Network Brought into Mix as Volunteers Assist in South African Fire Disaster
• South African Radio Amateurs Poised to Support Communication as Wildfires Rage  
•  “A major problem fighting the massive fires that ravaged Knysna  was the lack of communications and electricity outages"  -  HAMNET Report 25 June 2017
• South African Radio Amateur save lives - Maritime Rescue near Brazil 
• Three Amateur Radio Clubs provided radio communication during the World Renowned Mountain Ultra Trial (MUT) 2024
• Destructive Fire destroy and damage homes, cars and wild-life in Mossel Bay (5 - 10 January 2026)
• Amateur Radio Emergency Communications PDF - After Action Report 2017 Knysna Fires
  
• Amateur Radio Emergency Communications PDF - After Action Report 2018 Herold / George Fire 
• Amateur Radio Software provides notification of Strong 5.3 Earthquake - West of Brandvlei, SA, on Sunday, December 22, 2024, at 02:51 SAST
  

Image: Amateur Radio  Emergency Communications Field Station at St Blaize, Mossel Bay

Local Community Events where Radio Amateurs assist with communications:

• ISUZU Iron Man Competition - Mossel Bay
• St Blaze Mossel Bay Lighthouse - Radio Amateurs  participate in International Lighthouse and Lightship Awareness Weekend 
• Radio Amateurs (hams) and HAMNET members have historically assisted with communication in Blind Navigator Rallies
• Amateur Radio Communications: 2013 Mossel Bay Mini Air Race - 13 October 2013
• Great Teamwork by Radio Amateurs: 2013 President's Trofee Air Race: Oudtshoorn, South Africa (23 - 25 May 2013)  
• Amateur Radio H.O.T.A Activation: 1. 500 year old Post Office Tree 2. Dias Museum, Mossel Bay - 19 November 2022 14h00
  

Above is only a few incidents / events in which amateur played a important roll in providing services to the community and assistance during disasters.  I am sure many will agree if it was not for radio amateurs and their equipment many lives, homes and animals would have been lost on land and sea.

Health and Safety Concerns

Members of the public living near radio amateurs often express their concern about health risks when amateur radio operators transmit (Electromagnetic Fields aka EMF) RF using their radios. Amateur radio installations are governed by stringent safety standards.  ICASA adopts exposure limits from the International Commission on Non-Ionizing Radiation Protection (ICNIRP)  which align with the World Health Organization (WHO) recommendations.

WHO's extensive reviews included over 25 000 studies, conclude that low-level EMF from amateur radio poses no confirmed health  risks.  Radio amateurs are trained to evaluate their stations using tools like the FCC's RF exposure guidelines, adapted locally to avoid interference with aviation, broadcasting or emergency services.  In practice most amateur radio setups operate well below these thresholds, far safer than everyday devices like cell phones.

Official Recognition:  A Global and National Endorsement

Amateur radio's role in disaster response is officially recognized by the United Nations.  The ITU under UN auspices highlights amateurs in emergency telecommunications, noting their ability to provide voice, text, digital and data links in remote or devastated areas.  The United Nations Office for Disaster Risk Reduction (UNDRR) cites amateur radio as a resilient method for risk reduction, integrated into global strategies like the Sendai Framework.

In South Africa the South African Radio League (SARL= National Body for Amateur Radio in South Africa) collaborates with ICASA and provincial disaster management / agencies to embed amateur networks in emergency plans in all provinces. These partnership underscores amateurs as a "force multiplier" in crises as per United Nations guidelines.

More than Towers / Antennas:  Equipment of readiness and hope

Those amateur radio antennas and towers are not vanity projects but lifelines.  In the Southern Cape Area devastating fires, floods, wind storms and even earthquake risks, they represent not only preparedness but a necessity when disasters or emergencies occur.  The neighbor decrying a tower and antennas might one day rely on it for a distress call when all other means of communications fails. The Knysna Fire in 2017 is a reminder in this regard where it was reported:  “A major problem fighting the massive fires that ravaged Knysna  was the lack of communications and electricity outages"

Conclusion:  Embrace Radio Amateurs as they are the Guardians of the Airwaves

Radio Amateurs do not hinder communities - they fortify and assist their communities.  Under ITU and ICASA oversight, with the SARL's guidance and UN endorsement they embody regulated volunteerism and Ubuntu.  The next time a tower or mast graces the Southern Cape Area see it as a symbol of service; metal and wire woven into the fabric of safety and solidarity.  By supporting Radio Amateurs we invest in our collective resilience.

In the final analysis, while amateur radio have a storied past, the future looks even brighter. The fusion of traditional knowledge with contemporary innovations is set to usher in a golden era for
amateur radio. In the realm of crisis communication, amateur radio remain, as ever, a stalwart ally, poised to play an even more pivotal role in the future.

AMATEUR (HAM) RADIO IS THE ONLY FAIL SAFE COMMUNICATION SYSTEM IN THE WORLD!

Images:  Past and present events where amateur radio assisted communities in need.  (Click on images for larger view.)

 

ED.  This article would not have been possible without the contribution by many fellow radio amateurs, news papers, HAMNET  and the Internet.  To many to mention individually.  I do not claim in any way to be the owner of any of the content and information.  In my humble opinion it belongs to Amateur Radio.  All the inputs are highly appreciated.

Down Memory Lane: Amateur Radio and the Laingsburg Flood ( Sunday, 25 January 1981)

Image:  Laingsburg Flood  (Click on image for larger view.)

Today 45 years ago on 25 January 1981 the Laingsburg Flood occurred. 104 people died in the incident. Read more in the attached article that I wrote about the Laingsburg Flood after receiving a request from several schools who wanted to use it as an assignment. Amateur Radio also played a vital role during the Search and Rescue mission. See the photo beneath. 

THE LAINGSBURG FLOOD - 25 JANUARY 1981 (PDF 5 MB Download)

Amateur Radio assisted in establishing vital communications with the outside world.

“The memories will remain with those who witnessed and experienced this disaster” 

Wanted Urgently: Article - "Radio Amateurs do not hinder but serve their community"

UPDATE 21 January 2026:  Thank you to everyone that send me copies of various articles.  I will be using every single one of them.  You assistance in this regard is highly appreciated!

Wanted - Urgently.  Please help!   I am looking for an article that was written a few years ago. The heading went something like this:  "Radio Amateurs do not hinder but serve their community"  I cannot remember who the author was but it was written after a radio amateur's neighbor complained about his tower and antennas to a local authority. It also appeared in newspapers in the Cape Town area.  I need a copy of this article ASAP.  Can somebody help please!  The article is needed to inform (educate) a local authority  and the community in the Southern Cape Area about Amateur Radio . 

Send info by clicking HERE

AllStarLink / HamVoip has the best VOIP audio quality in Amateur Radio

During a resent "Sonsak Span" Net Pieter ZS3PV was visiting the Saldanha area. He used the AllStar node of Wikus ZSWLM-L that was connected to the ZS Link AllStar Hub in Mossel Bay.  Pieter could not believe the excellent audio quality that he received via the two allstar nodes.  He was adamant that  the audio quality is the best he ever heard on VHF and that he considers to setup an AllStar node in Kleinsee at his QTH.

Now I have to get the following of my chest before I continue.  I sometimes hear that fellow radio amateurs comment that  Echolink / AllStarLink / VOIP is not amateur radio as it uses the Internet and not RF radio communications.  

 

 

Image:  ZS-Link Network HUB, Mossel Bay  (Click on image for larger view.)

Is Echolink / AllStarLink / VOIP really not Amateur Radio? 

Now  Tom Salzer KJ7T comments in this regard is absolutely spot-on and I quote:

 

"Each approach has its place and each provides enjoyment and fulfillment for me.  I hear this question all the time, either posed as a sincere question or as a loaded comment deriding those who use AllStarLink. I submit that AllStarLink is as much connected to amateur radio as is Morse Code. In the beginning, Morse Code was transmitted over wires, not over the air. Radiotelegraphy required changing the use of Morse Code from something that actually printed on paper to tape to audible pulses of long and short sounds.

AllStarLink is not Morse Code, but like CW, it is a digital mode. Both of these communication modes can be used over the air or over a wire. That intersection with RF radios is why I think AllStarLink falls squarely in the realm of amateur radio. AllStarLink is also a grand experiment in adapting Asterisk for amateur radio use, an activity that is part and parcel of amateur radio. As amateurs, we adapt technologies and adopt methods from other fields. Some of us are theorists and some are pragmatists. All of us find something to enjoy in this very broad hobby of hobbies we call amateur radio."

Thanks, Tom for answering that question!!

I decided to provide more information in this article relating to AllStar as it seems that it does not get much airtime.  Echolink has been around for a while, as has DMR and IRLP. Why another digital voice mode like AllStarLink and how does it function?  AllStar technology can feel overwhelming to some radio amateurs.  This is far from the truth.  If you are prepared to read and spend a little time on it you will be rewarded with the best audio quality coming from your station. 

 

What is AllStar?

AllStarLink is a network of Amateur Radio repeaters, remote base stations and hot spots accessible to each other via Voice over Internet Protocol. AllStarLink runs on a dedicated computer (including the Raspberry Pi) that you host at your home, radio site or computer center. It is based on the open source Asterisk PBX running our app_rpt application. App_rpt makes Asterisk a powerful system capable of controlling one or more radios. It provides linking of these radio "nodes" to other systems of similar construction anywhere in the world via VoIP.

AllStarLink's primary use is as a dedicated computer node wired to your repeater or radio. Connections from Echolink, other VoIP clients and telephone calls are supported.

AllStarLink has 42770 users and 45117 nodes.

What is a node?

A node, in simplest terms, is a computer that connects to the AllStarLink network. Nodes typically have an RF radio interface as well as an internet connection. Radios can range in size from a repeater radio to a low power radio integrated into a node. A node allows you to connect to other nodes in the AllStarLink network.

Nodes take the form of an inexpensive Raspberry Pi computer or a PC running the Linux operating system.

How do I use AllStarLink?

If you have a local FM repeater that is AllStarLink enabled, you may already be using it! However, before attempting to control a local FM repeater, check with the owner(s) first before doing so -- ham radio etiquette applies.

AllStarLink is typically used in these ways:

• Via a FM repeater that is AllStarLink enabled. Controlled through DTMF commands, via the internet, or an autopatch.
• Via a local micro-node that is purchased by a HAM operator to join the AllStarLink network
• Via PC/Mac software that allows you to connect directly to a node. The microphone / speaker are used for audio.
• Via a mobile app such as DVSwitch Mobile to connect directly to a node.
• Via an autopatch

 

Getting on AllStarLink

• If you wish to create your own node, follow the directions below to create an account. After your account is active, you will need a suitable PC or Raspberry Pi computer to install AllStar onto.
• If you wish to use a local FM repeater that is AllStar enabled, you do not need an AllStar account. Check out our Active Nodes List to find a repeater near you. If you type your city name in the search box, you will be given a list of active nodes. However, before controlling any node via RF & DTMF, be sure to talk to the operator(s) of that node and receive permission first.
  • For a list of possible commands, visit the AllStarLink Standard Commands page.
  • Some nodes may be local/non public nodes, so look for information that the node is in fact public.
• If you wish to purchase a pre-made or complete node, check out our Radio Connections page for a list of vendors.
  

Benefits of AllStarLink (HamVoip)

AllStarLink benefits amateur radio operators by creating a global network for radio communication over the internet (VoIP), enabling long-distance/intercontinental chats, linking analog and digital systems (DMR, YSF), improving emergency comms with flexible infrastructure, offering high-quality audio, and providing control over personal nodes for enhanced privacy and customization, all built on open-source software. It allows for connecting handhelds to powerful repeaters or even controlling systems remotely, supporting various amateur radio activities from nets to simplex contacts. 

Key Benefits

• Global Connectivity: Link with other hams worldwide using your radio, bypassing geographical limitations through the internet.
• Emergency Preparedness: Offers resilient, alternative communication infrastructure for disaster relief coordination.
• Hybrid Communication: Bridges analog RF (radio frequency) with digital VoIP, connecting different radio types (DMR, YSF, P25) and even traditional EchoLink.
• High-Quality Audio: Uses business-grade codecs for clear voice communication, even with age-related hearing changes. Being able to clearly hear what is being said is becoming more important as hearing changes with age. The audio quality is excellent.
  
• Flexibility & Control: Build your own node, giving you autonomy, privacy, and control over your connection, or use pre-built solutions.  You can also purchase a fully functional allstar node
  
• Open-Source & Customizable: Built on open-source Asterisk software, allowing for extensive customization, scripting, and integration.
• Enhanced Features: Supports autopatch, remote control, scheduled events, and integrates with smartphone apps (DVSwitch) for broader access.
• Controlling Repeaters:  It can control repeaters or operate as an individual node in an AllStarLink network like the ZS-Link Network in the Southern Cape. When part of a repeater system, people can connect over radio or over an internet connection. I find this more inclusive than the idea that if you aren’t using a radio (or you aren’t a CW operator, or you aren’t using a vacuum tube radio, or or or), you aren’t really a amateur radio operator.  Hogwash!! 
• Versatility:  You can make simplex contacts or participate in nets, nearby or across the planet. While AllStar works fine for conversations with hams close by, it shines in situations where geographic distance would otherwise hamper conversations. If you are near a repeater with AllStarLink, you can operate over RF. If no such repeater is near you, you can operate over an internet connection.
• AllStarLink neatly solves the following problems:  Can’t put up antennas.  Too much RF interference to enjoy using radios over RF.  Living in a facility that prohibits amateur radios that transmit and receive over RF. 

Drawbacks of AllStarLink (HamVoip)

To say that AllStarLink does not have any drawbacks would be a lie.  So here are the drawbacks.

AllStarLink (ASL) is a powerful, Linux-based VoIP (Voice over Internet Protocol) system for linking amateur radio repeaters and nodes. While highly versatile, it has several drawbacks, particularly regarding setup complexity, hardware reliability, and audio quality management

. 

 

Key drawbacks of AllStarLink include:

• Complex Setup and Technical Barrier: Setting up an AllStar node requires knowledge of Linux, networking, and radio hardware. It is not a "plug-and-play" system for beginners, requiring configuration of Asterisk, Node-Ventures, or similar software.
• Hardware and Interface Issues:
  • USB Radio Interface (URI) Problems: Some USB interfaces (like the DMK URIx) have been known to have issues with EEPROM, causing them to appear as if they have failed.
  • Audio Levels: Users often report that audio levels are inconsistent across different nodes.
  • Component Failures: Raspberry Pi-based nodes, especially when used in high-demand or remote, unheated environments (like mountaintop repeaters), can be prone to intermittent crashing and need remote reset capabilities.
• Networking and Connectivity Hurdles:
  • NAT Router Issues: AllStar registration can fail behind certain NAT routers that do not maintain proper source-port preservation (expected to be 4569).
  • Firewall Configuration: Connecting to other nodes requires specific firewall port forwarding, which can be difficult for some users to manage.
• Audio Quality and Codecs:
  • Limited Codec Improvements: The system relies on older technology, with some users noting that audio codecs have not seen major improvements in over 20 years, relying primarily on GSM.
  • Audio Breakups: Some Raspberry Pi implementations have reported audio gaps and inconsistencies.
• Support and Documentation:
  • Poor Documentation: Access to up-to-date, comprehensive documentation is considered a weak point.
  • Support Forums: While a community exists, troubleshooting often relies on user-driven forums rather than dedicated, professional support.
• Dependency on Internet Stability: As a VoIP system, the quality and reliability of the audio link are entirely dependent on the stability of the internet connection; high latency or packet loss will break the audio.

Despite these drawbacks, AllStarLink remains a very popular, flexible system if the user is willing to manage the technical, hands-on nature of the platform.  Do not believe people who tell you  that AllStar is to complicated.  Nothing comes for free in life and if you get stuck there is more than enough competent AllStar experts out there to assist you.  I have no Electronic or IT background.  What I know today I have learned by reading, asking, watching videos etc.  If you have the will to be successful and you use your spare time wisely you will be successful in setting up and running your own AllStarLink Node.

I am not going to explain how to get started with AllStarLink or how to operate a node.  Google is your friend.  The Internet has nowadays an abundance of information on how the get started with AllStarLink.  The following three links will provide you with an lots of information.

AllStarLink Website:   Click HERE

HamVoip Website:  Click HERE

Ham Radio Crusader:  Click HERE

 

 

Image:  Flowchart of the ZS-Link Network HUB (Click on image for larger view.)  

 

Summary :

 

The cheapest and easiest way to participate in the ZS Link AllStar Network is to use a VHF handie talkie or VHF mobile radio to talk over the Aasvoëlkop Repeater that is already connected to the AllStarLink network via the ZS-Link HUB in Mossel Bay.

Next up is using an Android smartphone or tablet that you already have to connect to the ZS Link AllStar Network. 

Ultimately you can build or buy a node and connect it via RF or the Internet to the ZS-Link AllStar Network. 

 

Finally:  

 

More information regarding the ZS Link Network and Projects are available on our Blog by clicking   HERE.  This Blog is a real treasure trove and contains 847 posts up to today.

Building Low Budget Antennas - DIY Stacked J-Pole Antenna(s) for a 70 cm DMR Repeater (Part 1)

I do not like buying antennas if I can build my own that works just as well as a purchased antenna.  Throughout my amateur radio "career" I only purchased two Diamond X50 antennas.  One needed refurbishing after two month.  See article HERE.  Living by the sea takes its toll on any antenna if it is not very well constructed.  This is why I prefer to build my own antennas.  Be as it may this is my choice.  Others might prefer to purchase commercial antennas which is also fine. 

In this article we will be looking at building two  low budget antennas -  The DIY Stacked J-Pole Antenna(s) for a 70 cm DMR Repeater. Currently only a two stacked antenna as I will later add the other two that will result in a 4 element stacked J-Pole antenna.  The idea for this antenna was derived when I saw a product pamphlet in the shack of Nico ZS4N of  Hy-Gain's 4 Element 2 Meters Stacked J-Pole Antenna. I searched the Internet and only found copies of the advertising pamphlet on this 2 meter antenna and none on a 70 cm version of this antenna.  So I decided to roll my own.

Now why a J-Pole Antenna?  Glynn E. "Buck" Rogers Sr (68 years as K4ABT) tells us more:

The J-POLE has been around since the early days of HAM Radio, and is a direct descendant of the "Windom" Like the Windom or ZEPP, the J-POLE is a spin-off, or a modified WINDOM for VHF and UHF. One of the first articles I wrote about the J-Pole was in HRC magazine in 1958. Since 1958, I've written several j-pole articles in other HAM Radio publications.

Here, my references are to the early, 1923 (version) Windom (Article by Loren G. Windom September 1929, QST magazine) . If you look at the feed of the early Windom that was fed with a single wire, you may soon see the similarity between the Windom, ZEPP, and the J-Pole.

Look close at the configuration of the Jpole and the Windom, and you will understand why in many of my articles in CQ Magazine and other publications, that I often refer to the Jpole as a Windom, with the short section folded back on itself to form the parasitic element. It is for this reason that I feel these are two of the best antennas ever designed.

Having said this, you will also note that the Windom (and the Jpole) are powerful antennas that provide outstanding performance on all bands above the band for which they are cut or designed for. The reason these two antennas perform so well (as Multi-Band antennas; Windom for HF & lo VHF, Jpole VHF & UHF), is because they operate at harmonics of the fundamental or lowest frequency for which they are cut/designed. To add additional feeders (ladder-line), other than 50 ohm coax or UNUNs is a waste of RF energy. Only 50 ohm coaxial cable and a BALUN at the feed-point is all that is necessary. Anything more, adds losses into the equation that cannot be overcome after-the-fact.

Remember the axiom:

"When you have reached perfection, anything more becomes a point of diminishing returns." Enough said!

Trust me on the above paragraph, as I have experimented with every Windom and J-pole concept or design that can be imagined. Having built and sold thousands of these two antennas, I've found that
It's difficult to improve on perfection.

• For now, let's look at some of the features of our J-Pole, whether for; 140-150 mHz, or 430-450 mHz
• the J-Pole is easy to erect
• the J-Pole needs no radials
• the J-Pole has low angle radiation
• the J-POLE has greater bandwidth.
• the J-Pole has greater immunity to terrestrial noise
• the J-Pole is great for local nets or distant repeaters
• the J-Pole has more gain than most Ground Planes
• the J-Pole is more durable than most Ground Planes
• the J-Pole meets most "stealth" antenna restriction agreements
• the J-Pole has less static-charge noise, and static-charge build-up
• the J-Pole is a end-fed half-wave dipole 

The J pole antenna uses the stub to provide a good match to 50 Ohm cable. The feed point is moved up or down the stub to provide the best match, and adjustment can be made once the antenna is in position if required.

The main disadvantage is that it can be a little more difficult to adjust than some other forms. The reason for this is that impedance matching has to be accomplished by altering the trimming length of the stub.

Thanks, Buck  K4ABT!

Now I needed a 70cm Stacked J-Pole Antenna and the only information that I have was the two images above and the info from Buck K4ABT,   No measurements or images for a 70cm version!  I decided to design my own 70cm version from scratch and sorry Buck I might have transgressed the axiom here?

I looked at the second image depicting the two meter version above.  I decided to "invent" my own way of building the 70cm version of the Stacked J-Pole Antenna.  I used an online calculator to calculate the 70cm dimensions.  However the final dimensions for my version of this antenna differ significantly from the calculator which is fully understandable as the feeding arrangement and parts used is completely different to the traditional version of the antenna.  Up to now I could not find any information about this Stacked J-Pole Antenna for 70cm.  I however now have all the information at hand after constructing two of these antennas.  

The dimensions for the antenna was calculated using a free antenna calculator program (available for download from here). I set my frequency to 438.260 MHz. The resulting calculation is shown in Figure 1 below. 

 

The above dimensions did not work for the upside down J-Pole antenna for 70cm.  Here is the dimensions that worked for me.

Herewith the small amount of info that I have about the antenna:

The antenna is a high performance all driven stacked array of vertically polarized dipoles (J-Poles) that presumably delivers 6-9 dBi (or 4-7 dBd) or more omnidirectional gain.  Uniquely designed phasing and matching harness maintains a perfect parallel phase relationship and is center fed to minimize beam tilting for better low angle radiation.  The driven element maintains an extremely broad band response and effective isolation from the supporting mast only if the correct distances is set.  Open construction minimize failure due to moisture and condensation.  The entire antenna is DC Ground for static removal and lightning protection. Feeds with a good 52 Ohm coaxial feed-line.

Electrical Specifications:

Gain:  6-9 dBi (or 4-7 dBd) (2 x Phased Stacked J-Pole Antennas)

Power Limit: 1 Kw PEP

VSWR (at resonance):  1,1:1  Note:  Using the NanoVNA not connected to the computer I obtained a 1:1 SWR but using the NanoVNA Saver program the SWR was reflected as 1.4:1 and 1.2:1.  Why is still a mystery.

Impedance: 50 Ohms

Mechanical Specification:

Mast Height:   To be calculated 

Isolators:  Stauff  Gr 2

Mast Diameter:  50 mm

Wind Survival:  100 km/h

With all the information now on paper, I was ready to move onto the next phase and that was to gather all the materials I was going to need.

Materials that I used for one antenna:

1 x 200mm x 38mm x 38mm x 2mm Aluminum Angle Iron

1 x 12mm x 2mm x 2.5m Aluminum Round Tube  (The thicker the wall thickness the better. 2mm is rather thin.)

1 x 1 meter x 10mm x 2mm Aluminum Round Tube

1 x 30 mm x 10mm Wooden Dowel 

2 x 22 mm Plastic End Caps to fit into the 25mm Boom ends.

1 x SO239 Connector (Optional)

2 x Electrical Eye Lug (Terminal)

1 x 12mm Stauff Clamps (Insolaters between boom and elements.)(See images)

2 x 45mm x 5mm Stainless Steel Bolts + Washer + Lock Nuts

2 x 40mm x 4mm Stainless Steel Bolts and 2 x Lock Nut

2 x 6-16mm Stainless Steel Hose Clamps

2 x Stainless Steel TV - U Clamps

1 x 150mm x 80mm x 5mm Aluminum Flat Plate to mount antenna to boom.

1 x 100mm x 3mm Solid Copper Wire

Odds and Sods:

Hot Glue Sticks

Self Amalgamating Tape

Solder

Solder Paste

Marine Silicone Sealant

Heat Shrink Tubing

 

Tools:

 

Metal Punch

Drill

Various Drill Bits 3mm - 8mm

Hack Saw 

Hot Glue Gun

Soldering Iron

Screw Driver (Small flat)

Alen Keys 

Spanner Set

Small Pipe Bender (See images)

 

Test Equipment:

 

SWR Meter

Antenna Analyzer (If you have one but not compulsory)

Amateur Radio Transceiver

Coax Patch Leads

Mast (Non conductive)

Coax feed line cable  10 m  RG58CU 50 ohm

Power Supply for Radio 

Bending the J-Pole Element:

(Click on images for larger view.)

Now how did I bent the 180 Degree bend of the antenna?  I used a small pipe bender.   The 10mm aluminum tubes are cut to 1 x 565mm length.  I made a mark at 465mm on the long side of the antenna.  On the short end I measured 120mm and made a mark.  The first mark on the long side is placed on the 0 | 0 mark of the pipe bender.  Now start bending until the 0 on the top lever reaches the 180 mark on the bottom lever.  You now have a 180 Deg bend and your J-Pole antenna element.

I am not going to go into detail how I further constructed my version of the antenna. I will however describe my findings in constructing and testing the antenna.  The images below provide good detail of how I constructed the 70cm Stacked J-Pole Antenna.

My build observations and findings:

I used the material that I had in my "Junk" Box.  The aluminum was left overs from other antenna projects.  Measurements is absolutely crucial and feed point connections must be short as possible for obvious reasons.

I used the outer braid of RG58CU Mil-Spec to connect the 3/4 wave element.  The 1/4 wave radiator is connected using a short piece of 3mm Solid Copper Wire.

Tuning the J-Pole correctly is very important:

Tuning a J-pole antenna involves two main steps: adjusting the overall length to set the resonant frequency.  With this upside down J-Pole the one feed point (tap point - 3/4 wave element) and the joint between the 10 and 12mm is tuned to achieve a 50-ohm match and 1:1 SWR, all while using an SWR meter or antenna analyzer for precise readings at your desired frequency. You adjust the lengths of the main radiator and the stub (shortening to raise frequency, lengthening to lower it) 

Tools Needed

• SWR Meter or Antenna Analyzer
• Coaxial cable
• Tools for cutting/adjusting wire/tubing

Tuning Steps

1. Initial Setup: Mount the J-pole at its final operating height, away from ground/obstructions if possible, and connect your SWR meter/analyzer between the radio and the antenna's feed point.
2. Find Resonance (Length):
   • Measure the SWR across your desired frequency range.
   • If the lowest SWR dip is below your target frequency, the antenna is too long; trim a little from the ends (main radiator and stub).
   • If the lowest SWR dip is above your target frequency, the antenna is too short; add length.
   • Repeat trimming/adding in small increments until the resonant frequency (lowest SWR dip) is at the center of your band.
3. Match Impedance (Feed point):
   • With the antenna resonant at your frequency, find the point on the 3/4 wave element and the 1/4 wave radiator for the lowest SWR and 50-ohm match point.
   • Once you find the right points for the lowest SWR and 50-ohm impedance your antenna is now tuned.
     
4. Add Common Mode Choke: Install a choke (ferrite beads or a few turns of coax) at the feedpoint to prevent common-mode currents, which improves performance.
5. Final Check: Re-test across the band to ensure good performance and bandwidth.

Key Considerations

• Two Adjustments: J-poles need both length (frequency) and feed point (impedance) tuning.
• Bandwidth: J-poles have narrower bandwidth than dipoles, making precise tuning crucial.
• Material: Use bare wire or tubing for best results; insulation affects performance

Theoretical Performance of a 70cm stacked J-Pole Antenna:

A 70cm stacked J-pole antenna, essentially two J-poles combined (often a 2x5/8 wave design), offers increased gain over a single J-pole, pushing into the 6-9 dBi range (or 4-7 dBd)

, providing a lower take-off angle and better range for 70cm (UHF), ideal for repeaters and long-distance simplex, but its performance depends heavily on precise construction and stacking distance for optimal phasing. 

What to Expect with a Stacked J-Pole:

• Increased Gain: Stacking elements (like two J-poles) concentrates the radiation pattern, adding gain, often resulting in 3-6 dB more than a single unit, pushing it from a typical 3-5 dBi J-pole to higher figures.
• Lower Take-Off Angle: This design provides a lower angle of radiation compared to a simple dipole, which is excellent for FM voice communication and hitting distant repeaters.
• Performance: You can expect good range, with some users reporting success reaching distant repeaters or even simplex contacts (e.g., 40-80 km) with modest power (3W+).
• Construction Matters: For dual-band 2m/70cm stacked J-poles, the 70cm performance often involves a 2x5/8 wave design, requiring careful tuning and phasing for both bands.

Typical Gain Figures:

• A single J-pole is often around 3-5 dBi.
• A stacked 2x5/8 wave 70cm J-pole can reach 6-9 dBi (or 4-7 dBd), depending on the design and how well it's stacked.

In Summary: You're looking at a medium-to-high gain antenna for 70cm when you stack J-poles, making it a significant upgrade for FM and weak-signal work on that band.

Finally:

I really did not go into a full-out testing and use of this antenna at this stage.  The only testing I have been doing is using one J-Pole at a time with the Nano VNA.  See images below for the test results.

The next step will be to stack and co-phase two of the antennas and then test it again with the NanoVNA and also installed on a mast. I will provide more feedback and details in a future article on how the DIY Stacked J-Pole Antenna(s) for a 70 cm DMR Repeater performed.  Stay tuned!!

Images:  (Click on images for larger view.)