International considerations

These days, anything we write on the internet can be read all around the world. While generally that is a good thing, it also means that we have to be aware that some readers won’t share the same language, context, understanding, materials, etc. that we take for granted.

I’m trying to be aware of that in my writing, and addressing it in the following ways:


I write in English (and a particular dialect of American English at that). Not being fluent in other languages, it is the only way I can do it. But I understand that English is not the native language for many readers. Hopefully I can write in a style that less fluent readers, or online translators, can make sense of it in combination with drawings and photos. At some point I plan to add a glossary, defining words that are less common, even for some native speakers of English.

If you have questions, especially about parts of articles that are difficult to understand, you can email me, even if your English is not very good, and I will do my best to answer your questions. If you can’t express it in English, I will do my best with an online translator or a language dictionary. The important point is to communicate. (Some might complain that I spell aluminium or metre incorrectly, but that shouldn’t keep us from understanding the meaning of the word.)

Metric and Imperial Units

This is important enough to have its own separate page. Basically, I plan to give all measurements in both sets of units, with an appropriate resolution for each, as well as adding tables of standard sizes for pipes, screws, wires, etc. to the Resources page.

Numbers Formats

This can cause great confusion to those who haven’t encountered different formats for writing numbers that are in use around the world. I will write numbers in the style I am used to, but will take this opportunity to document that style for those who might read it differently.

First, I use “.” (period, or full stop) as the decimal point. So one half would be written “0.5”. I know some use the comma (“,”) or a raised point (not on my keyboard) for this.

Second, the standard thousands separator in American English is the comma. To avoid confusion for those who are used to using it as the decimal point, I plan to avoid using it altogether, either using metric prefixes or exponential notation to make the value clear, or just leaving spaces instead.

And then there are those weird fractional inch measurements, like 11/32″ (“eleven thirty-seconds of an inch”, about 8.7mm). I will try to avoid them wherever possible, along with the common abbreviations using the single quote (or apostrophe) ‘ for feet and the double quote mark ” for inches, which are easy to misread or misunderstand. You may, however, run into them on other websites. I’ll also include a table of common fractional equivalents on the Resources page.

Frequency Allocations

While some of the HF ham bands are standardized around the world, there are exceptions. Probably the most common ones that will affect this website are the wider bands at 80m (3.5 – 4.0 MHz), 2m (144 – 148 MHz), and 70cm (420 – 450 MHz) in the US, as well as the 6m band (50 – 54 MHz) that is a comparatively recent allocation in some other countries. For example, I generally would design a 2m vertically polarized antenna for a center frequency of 146.5 MHz, since most of the FM activity using vertical polarization is in the 145 – 148 MHz range. Those with a narrower band might want to shift the center frequency to 145.25 instead. Similarly, our 70cm FM operation is in the 440 – 450 MHz range. So pay attention to the SWR plots and see how suitable the design is for your needs as stated, or if it will need to be shifted to match your local allocations.

The wide 80m band has its own issues. SSB operation used to be permitted only above 3.8 MHz (often referred to as “75m”), with CW at the bottom of the band. Designing an antenna to cover both segments is not a trivial exercise. I have articles that address this, but feel free to ignore them if 80m bandwidth isn’t a problem for you.