More on Antenna Modeling

The previous post on EZNEC being offered gratis to the Amateur Radio community had some comments, and I received a few emails. (Link )

Much of what had been in computer antenna modeling has changed over time.

I gathered as many links as I could find for this post.  If you know of additional programs or links, please put them in a comment, and periodically I will edit them into the main post.

(NOTE:  Focus is on general HF Amateur Radio level usage programs)

Antenna Modeling Links – mid-May 2022:

Active Programs Found

Linux Active Programs Found

Links that work, but the programs are not fresh (may be DOS or WinXP):

Replaced by newer offerings

Defunct Links

  • NEC-Win-Plus – defunct was Nittany Scientific, who is out of business
  • NEC4WIN – defunct – was Orion Systems
  • SuperNEC – defunct

About NEC (the engine at the center of these programs)

NEC Alternatives/Derivatives

Other Useful Links:

ARRL Links



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EZNEC Antenna Modeling for All of Us

I missed this while it was happening. I was looking to update my old software to model my new antenna configurations and found out about the change.

As Roy W7EL decided to retire, he made public his EZNEC antenna modeling software (compiled form only).

There is also some neat stuff on NEC-5 end, where there is a collaborative update to the latest version (NEC5 X11) thanks to some great ham inputs!

The AC6LA add-on AutoEZ is something I plan to check out. and

AutoEZ is interesting as it an an Add-On to EZNEC which in also in essence an Add-On to NEC.  AutoEZ appears Excel-based, EZNEC is Visual Basic 6 (obsolete version) with some Fortran modules,  and the core NEC compiled Fortran (Intel Visual Fortran with the mkl math libraries).

Below the “–” line I will include some background from either Roy W7EL (website archived copy or or a QSO Today Podcast interview he did with Eric 4Z1UG.

Well worth checking out all of these programs.

Also a series of dedicated books by ON5AU that should be considered if you are going to put EZNEC to work:

GL and 73


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Dayton/Xenia Hamvention 2022 – New Memories or Just an Old Memory?

It is less than two weeks to the Dayton/Xenia Hamvention 2022 event.

So far I have spoken to only a couple of hams that are planning to attend this 2022 event, from the group who I’ve either done part of past Hamventions with or would get together with them at Hamvention.

The numbers from my area going to Dayton/Xenia seem significantly down – maybe 25% of the usual group is going.  Haven’t heard of any of the younger area hams going at all.

Here are some of the reasons I have heard:

  • CCP-19 Virus (aka Covid-19) remains a biggie.
  • Costs of fuel and everything else.
  • Low Awareness of Anything New
  • Uncertainty – here less than two weeks prior the isn’t a definitive health statement making one uncertain if even the organizers harbor concerns with gathering up so many hams
  • The combined Greene County/Ohio State Sales tax burden (said to be 8.75%?!)
  • Same deals being offered on the internet as are available if you attend.
  • So many items being out of stock, so if you want to buy you are placing an order rather than walking out with the cutting edge XYZ-123 unit then and there
  • Many of the Dayton era attendees are simply “old” and not travel-able
  • Lower numbers of DXpeditions and missed years means less war stories to be be told at Hamvention
  • Hams having missed previous events are struggling to reclaim their “Dayton Time Window” from among other family plans and pressures that took over.
  • Reduced event Promotion – many hams said they didn’t get the mailings and emails that strategically used to appear to puff up the event and banquets.
  • Alternatives (Hamcation being somewhere warm in Winter was mentioned by snow country hams)
  • Less exhibitors (see

I am not going, but really not for any one single reason.

Rather in my personal take the ROI (Return on Investment) for attending Hamvention is all about people – the other hams I know and can meet there. Since so many are giving Hamvention 2022 a miss as I’m not eager to drive and attend alone.



Creating Durable Systems – Vintage Station and Integration

Creating Durable Systems within the K9ZW Main QTH Shack is a series started with:

The Vintage Station and Integration system can be broken down further:

  • Collins HF-380/Alpha-95 setup (Home QTH)
  • Collins S-Line 32s1/75s1/30s1 setup (Home/Work QTH)
  • Collins S-Line KW-2A setup (Island QTH)

Both S-Line stations are currently receiving massive-TLC at the hands of Chuck W9KR, and should be ready by early summer.

The HF-380 station is ready to go.

The needs for each stations final build-out, testing and commissioning include:

Collins HF-380/Alpha-95 setup (Home QTH)

Station requires a few additional jumpers, but is otherwise ready to use and had been on the air.

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Thinking Ahead – Changing your habits for personal privacy and anonymity as an Amateur Radio Operator

I’m a Ham or am I? When to be noticed and when to be unnoticed, and much much more!

One should always remember that as a ham, you are already “on a list” in an official sense.  It is that “list” that records your callsign.

But there are times when it is useful to have more personal privacy and perhaps a bit of anonymity.

Physical Addresses:

If you look through listings ( or FCC searches) you will find plenty of hams who use a either a work address or a Post Office Box address. If you do this out of concern for your privacy consider whether you should use the same addressing for purchases, as

In many areas a tax search on your name can locate your QTH, but again you see people using trusts or LLCs to sort of throw a drop-cloth over their QTH, often followed with using a Post Office Box address or Business Address for official records.

Unless you are willing for forgo your cellphone, drive a pre-OnStar era car, and go to some fairly involved efforts fully shielding your QTH’s location is not going to happen.

What you are targeting instead to make your location less searchable in casual search attempts.

And remember if you start communications from your actual QTH it won’t be an uncompromised “safehouse” anymore!  In most cases that really isn’t a big issue, as long as you remember that your QTH will be a known “Radio Active” place.

Personal Privacy:

You make your choices whether to put your callsign on your license plates, wear “ham radio hats & clothes” or to take a less obvious stance.

One one hand we are enjoined to promote our hobby, offer Elmering tutorship and encourage others, though we seldom pause to think that we lost part of our personal privacy the moment we share our callsign.

It is perhaps impossible to completely maintain personal privacy and be a licensed & active ham.


This is all about You!

Some personalities end up being standouts and memorable whether intended or not.

People remember extremes and emotional responses.

If your vehicle bristles of antennas you become obvious.

So if you are super tall, you will struggle to maintain anonymity – you can do it but it is hard and requires extra efforts.  Squeaky or kettle-drum voice are ones that get noticed.

Attire can make a difference, as I once knew a salesman who called on me regularly  always wearing a goofy hat, as he was otherwise rather anonymous.  Decades later I remember his hats, but not his face or even his name.

In “Prepper Circles” they speak of become a “Gray Man” as the idea of becoming someone who isn’t seen as a standout externally despite having skills, capabilities and resources that would otherwise be noteworthy.  Usually the prepper-logic is being a Gray Man helps keep troubles from finding you.

All in all maintaining personal privacy and anonymity as an amateur radio operator is challenging and by definition can never be 100%.  But you do not have be totally revealed either!



Upgrading SDRs in Perspective (with Pro-Tips)

Writing this late the week FlexRadio rolled out a new version of SmartSDR v 3.3.29 and some radios had problems completing the update.

Per Facebook and Flex Community postings the internal SD Cards in a limited amount of mostly older original series radios (6300/6500/6700) are vulnerable to fatal corruption.

The solution is a replacement SD Card from FlexRadio, which they can either send to the operator or the radio can be sent in for an SD Card replacement.

As usual the posts about the small percentage that develop this temporary problem are emotional. Bluntly some folks are “drama queens” or worse.  Their core need and problems are exactly the same though from reading of their woes the certainly have personalized the problem.

About these SD Cards:, first a FlexRadio discussion about SD Cards:

Personally, I have had a SD Card fail in one of my radios. This one failed in Alpha Team testing, so it wasn’t at the same time other groups of radios had problems.

A bit of background, while a robust technology SD Cards are designed to be read and wrote to, over and over. The SD Card market offers a lot of claims about performance and durability not always achieved in field use.

So as a part of upgrading there is a bit of Stress Test through all the upgrade manipulations that can identify iffy SD cards, and some SD cards simply will fail.

Inconvenient but not horribly catastrophic – if the SD card fails you open a Help Desk ticket and FlexRadio sorts you out a fresh SD Card.

Your radio usually will be inoperable until the new card is installed, but it is NOT permanently bricked as many hand wringers lament.

Some lament why doesn’t FlexRadio offer an image that could be downloaded so the operator could roll-their-own new SD Card?

FlexRadio Systems is all about their customer’s experience, and their served customer base includes hams who understand every nuance of the radio’s design, have the techniques to deal with every level of repair – a the way through to – customers who on their own shouldn’t be inside the radio.

The image files appear not to be one-size-fit-all, and have evolutionary differences. I am uncertain if they are the same across all the world wide market of FlexRadio.

FlexRadio is using high grade SD Cards selected to best perform in their radios. While the SD Cards you buy from Amazon or other vendors could be the same, they also might not be at all the same.

So FlexRadio has kept the variables to a minimum by being the image-loaded SD Card supplier for the radios.

Not working for FlexRadio I am not privy to how big is the SD Card matrix they work with. The impression I have gained is that there are a lot of considerations for what version SD Card image is the right one for your particular radio.

My theory on why SD Card problems show up despite a huge testing processes is simple – there are radios which had SD Cards out in the general user population, where the test team with all their upgrade/downgrade/test processes largely have weeded out the suspect SD Cards long ago.

I think that is what happened to the SD Card I lost.

So in summary, if your SD card breaks during an upgrade:

  • Open a FlexRadio Help Desk Ticket
  • When you new SD Card arrives, install it
  • Then you will be able to complete your upgrade process.

Additionally (or Pro-Tips learned the hard way):

  • When an update comes out, unless you want to be bleeding-edge up to date, consider letting others “break trail” and wait a few days.
  • Never Ever – REPEAT NEVER EVER – even think of updating right before (or during) a contest you are participating in, or if you are about to do some important operating like a special DX chase or a shack tour.
  • Think about when in the week you want to run your updates – I try to do them late Sunday or on Monday, just in case.
  • If your budget allows, consider having a second radio (Flex-6300s are at a nice price point secondhand).  Some hams have a full set of duplicate gear so they can plug-n-play if anything goes down, though that strategy requires deep pockets.

Hoping your updates may always be successful and easy!