͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ 
Is this email not displaying correctly? View it in your browser.
KJ6ER Antennas

July 2026

Introducing the New Antennas Primer 2:

Antenna System Efficiency

Effective Radiated Power (ERP)

Dear Fellow Portable Antenna Geeks 😀

Perhaps one of the most misunderstood and confusing topics of amateur radio is Antenna System Efficiency ... with the emphasis on System. When you generate 100 watts from your transceiver, how much of it is actually radiated by the antenna structure? What happens to the RF energy as it travels through the coax? How does SWR impact this energy? Where does radiation efficiency come into play?


These, and many other topics, are the focus of my new Antennas Primer 2: Antenna System Efficiency and Effective Radiated Power (ERP). I analyze this in depth within three fundamental blocks: 1) Signal Source, 2) Transmission Feedline, and 3) Antenna Structure. Similar to my KJ6ER Antennas Family document, you can download the new Antennas Primer 2 as a PDF or PPT.


The advantage of the PPT version is that you can run it in PowerPoint Presentation Mode to see animated builds of each slide which may make it easier for you to understand. When you download it, Google wants to open it in Google slides. Just click File / Download / Microsoft PowerPoint (.pptx) to save it as a PPT file on your computer and open it from there. And if your Amateur Radio Club is interested in a presentation of this content, please let me know!


Last month, we introduced new Antenna Kits (Ant-Kits) that you can assemble yourself to save money, and heat shrink Band Labels (Band-Its) for your elevated radials and counterpoises. You can also request custom variations of KJ6ER antennas and accessories by clicking Request Custom Order at our Etsy store. We also just introduced a new 30M-40M elevated tuned radial set for your PERformer quarterwave antenna. Take a look!


If you do not have the time, ability or interest to build your own KJ6ER antenna, you can purchase a beautifully assembled handmade antenna system as well as accessories on Etsy. More than 300 products have already been sold at the J-Systems Store on Etsy since June 2025 with over 70 perfect 5-star reviews from buyers.

Antennas Primer 2
Antennas Primer 2
Antennas Primer 2
Antennas Primer 2
Antennas Primer 2
30M-40M Add-On Radial Set
J-Systems Etsy Store

Antenna System Efficiency requires a complete power accounting from the signal source (transceiver) through the transmission line (coax) to the antenna structure. The new Antennas Primer 2 helps you understand how coax losses (matched line loss) couples with SWR at the termination (antenna feedpoint) to deplete the power even before it reaches your antenna. Once it does, antenna gain (directivity and radiation efficiency) ultimately determines how much of the delivered power is radiated by the antenna. And it is probably less than you would expect!

Three Fundamental Blocks

Perhaps one of the greatest sources of power loss in your antenna system is your coax - not your high SWR! Inexpensive, poorly manufactured coax can rob you of almost half your power before it even reaches the antenna structure! When it does, the SWR at termination delivers most of that power to your antenna on the first pass, but also reflects some power back to the transceiver which is then re-reflected back to your antenna again. As this bouncing process continues, your power is subject to even more coax losses. Thus, SWR should not be considered an antenna performance metric. Rather, it is much more relevant to the quality of your coax.

Transmission Line

Once your power reaches the antenna structure, total antenna gain is determined by both radiation efficiency and directivity. Unfortunately, these parameters cannot be easily measured in the field but are calculated by computer modeling programs such as 4NEC2 that I use. This is why in all of my antenna designs, I share these modeling metrics and radiation charts to help you better understand how the design converts delivered power into radiated energy instead of heat, and how it shapes and concentrates radiated energy for directivity. As you know, radiation efficiency is my top performance priority when I design antennas.

Antenna Structure

This Month's KJ6ER Antenna Heroes

Each month I feature videos and blogs of hams sharing their own personal implementation of a KJ6ER antenna including how they built and deployed it, as well as how it performed. This month I am featuring three popular YouTube hams who all recently shared a video on the KJ6ER PERformer quarterwave antenna. One analyzes the radiation intensity of elevated radials, one builds his own unique version of the antenna, and the other deployed a 3-element configuration on the beach for amazing DX results. All are fun to watch, take a look!

Dave Owen G3LRC

Dave Owen G3LRC of Derbyshire, England recently posted a fascinating video evaluating the radiation intensity of different numbers of elevated radials on a quarterwave antenna. He featured the PERformer with two elevated radials in his presentation and came up with some amazing results. Take a look at what he discovered. Dave has an excellent YouTube channel featuring many different ham radio topics and interviews. Subscribe to his YouTube channel.

Stu Crawford VE9CF of New Brunswick returns as a Hero this month with yet another fantastic video featuring the PERformer. This time, he takes it to an extreme and deploys a 3-element PERformer with both a director and reflector on the beach! He ended up with a total of 197 QSOs, which included 42 DXCC entities - an amazing result! He was impressed with both the forward gain and the front-to-back of the antenna system. Subscribe to his YouTube channel.

VE9CF YouTube Video
Sean Klechak W9FFF

Sean Klechak W9FFF of McHenry, Illinois builds his own unique version of the PERformer with parts and components carefully curated from Goodwill and AliExpress for less than $50 total. In this video, he takes you step-by-step through his personal build and then successfully deploys it at a POTA activation achieving 60 QSOs in 45 minutes! He has a very popular YouTube channel called Dude Tested which covers a very broad range of ham radio topics. Subscribe to his YouTube channel.

If you would like your video or blog featured in one of my upcoming newsletters, share how you are building and deploying your own KJ6ER antenna. You will get visibility with thousands of my newsletter subscribers worldwide! Send me a link to your online content about any of my antennas and I will feature it in one of my future newsletters! I am very interested in how you customized the build for your own needs either as portable or at your home QTH. I know many of these wonderful antenna videos and blogs already exist - send me a link to your favorite.

KJ6ER Heroes Program

Visit the KJ6ER Website

Your one-stop shop for everything KJ6ER can be found at my kj6er.net website! I update the site on a daily basis with all my free Antenna Designs, access to my Antenna Geeks List, links to the Etsy store offering handmade KJ6ER Antennas and Accessories, recent Press and Interviews, a list of my Favorite Ham Radio Websites, as well as a complete Monthly Newsletter Archive. I want to sincerely thank the thousands of you around the ham world who have already visited the site. I will keep improving it!

KJ6ER Website

KJ6ER Beta Testers Program

As many of you know, I introduced a KJ6ER Antennas Beta Testers program recently to encourage interested hams to get draft PDFs of my new antennas in advance, build and deploy them, and then summarize their experiences with me. If you would like to become a KJ6ER Antenna Beta Tester, send me a message. Your early review of my draft PDF, antenna design and build helps me improve the content quality in the PDF, as well as the construction and deployment process.

ABR Coaxial Cables

Why not buy yourself a well-deserved gift of a fresh set of high quality ABR coaxial cables. If you use my callsign KJ6ER as the coupon code at check-out, you will receive a nice 10%-20% discount on your total order! Get your new ABR cables today!

Until next time, keep having fun out there! Building ham radio antennas is our last homebrewing frontier and I am dedicated to helping you do so successfully! See all my free antenna design plans on my website and at the cloud links below.



If someone forwarded this email to you and want to be added to my antenna geeks email list, send me a message and you will be the first to receive new KJ6ER antenna designs and updates! I am also available to present my antennas to your Amateur Radio Club via Zoom. Let me know if they are interested! 



As always, feel free to reach out to me if you ever have any questions, I'd be happy to help you! 🙂 73 KJ6ER, Silicon Valley

My mission is to design efficient and effective portable antennas for the every-ham that focus on the optimal integration of performance (high radiation efficiency), elegance (speed and simplicity of deployment) and convenience (ease of transport and storage). These designs are always shared for free with the global amateur radio community to encourage more radio operators to homebrew their own portable antennas. 

KJ6ER Antennas Website

Cloud Drive File Links (KJ6ER):

Greg Mihran, KJ6ER

Campbell, California

Visit My QRZ Page!

If you would like to unsubscribe, please click here.