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  •  About 

• Seen something in this site which doesn't work? - let me know!
• Have suggestions for site improvements? - I'd love to hear them!
• Just want to tell me how much you like the site? - I'm all ears!
• Don't like this site, or what it has to offer? - I won't hold it against you!

Design, development and maintenance by:  Rob, DM1CM

This website does not use 3rd-party cookies, is not monetised, does not contain or use advertising, tracking, or analytics of any kind, and does not receive or store any user data.

I must admit I've always been very reluctant to call attention to my self, preferring to let my work - such as it is - speak for itself.  However, so many people have made enquiries as to who is behind the site, who has developed it, whether it's a commercial site (it isn't!), and so on, that I felt I ought to at least give my name and callsign, so that those interested can do research online to discover more about me.  A few details are given in my QRZ.com page and a few further references can be found in various forums.

I previously developed the sotamaps.org website for SOTA, and the mapping routines for the IOTA website: both are still running at the time of writing.  The precursor to this present portable-antennas.com website was a single page in the sotamaps site, a Linked-Dipole Antenna designer, which calculated wire lengths and angles, but which had no access to a NEC engine, and so offered no radiation patterns, VSWR chart, etc.

Starting in 2022, I began to work on what would become this present site, by including a new version of the Linked-Dipole designer and adding a couple of new antenna types.  I also wanted to include radiation patterns and a VSWR chart, but wasn't quite sure how to do this.  After searching for software to enable such diagrams to be created and displayed, I did find some which enabled me to add them into this site - thanks to Ralf Schlatterbeck for those.  These python-based routines used a custom version of the old NEC v2 antenna modelling code.

This move enabled me to complete the first draft of this website, which went live at the end of May 2023 with just four antenna types; I subsequently worked on developing pages for other antenna types.  In the meantime, since those 3rd-party antenna plotting routines I was using turned out to be rather slow and inefficient, I wanted to replace them with newer, faster routines.  Eventually, in May 2024, I "graduated" to using a NEC v4.2 engine licensed to this site, and developed my own set of routines running on the back-end server to extract relevant information from the NEC-generated data, and also developed a complete "home-grown" set of routines for plotting radiation patterns diagrams, VSWR chart, antenna currents diagram and Smith chart.

As is mentioned elsewhere, this site is a work-in-progress, with updates, corrections and new features being added as time permits.  If you find an error in the site, or would like to suggest improvements to the site, please use the Contact form above to let me know.  Even if you have found no errors, or have no suggestions for improvement of the site, I would be delighted to hear from you.  It can be a little frustrating for a website developer to offer a site like this which is used by hundreds of people every day, and yet hear from only a very few of them (30 messages to date since May 2023!): I have no idea as to whether the others  - you - actually like the site, find it useful, or maybe not.

Nonetheless, I hope you enjoy the site!
73, de Rob DM1CM - June 2025

PS: I occasionally use the "royal we" when describing various features in this site, not to give myself more credit than I ought to do, but rather in some way to acknowledge the immense debt of gratitude I owe to all those hard-working developers out there whose work I have so shamelessly copied and purloined.  We are all brothers in this endeavor.

I've recently updated the software used in this site to generate antenna radiation plots data, and also the plot routines themselves. By developing my own software to analyze the NEC-generated data, and my own chart-plotting routines, I have eliminated several third-party software "plugins". This has resulted in tighter, faster data flow to you, the user.

• NEC v4.2 radiation plots data generator:  under license from Lawrence Livermore National Laboratory
        at   https://softwarelicensing.llnl.gov/product/nec-v42
• Javascript-based 3D charting library:  Plotly.js 3D Charts  at https://plotly.com/javascript/3d-charts/
• Javascript- and SVG-based charting libraries:  highcharts  at https://www.highcharts.com/
    - as a non-profit organization, the highcharts libraries may be used by this site without a license.

I am grateful for the opportunity to use these resources, and acknowledge a sincere debt of gratitude to their respective developers.

Please note:  due to the reliance on sizeable graphics and groups of controls in this site, it is not suited to display on small screens. I apologize for any inconvenience this may cause.