Category: DX Commander

2-element on top for 20m band and 3-element underneath for 10m band. Still prototyping. Should be operational shortly.

Just a quick update from the field today. I’ve been going round the mast adding a bit of threadlocker to the fittings and doing a few small tweaks after the recent rebuild. Nothing major – just part of the ongoing process of getting everything settled and working exactly as it should.

I also learned something interesting about how the mast sits depending on wind direction, which is worth noting for anyone building something similar.

The rest of the video is just a bit of footage from the field – including some drone shots I thought you might enjoy.

*** And finally, a genuine thank you to everyone who supports what I do. Customers, viewers, and those following along on YouTube – none of this would exist without you.

73,
Callum M0MCX

Why didn’t I just buy a lattice tower? It’s a question I get all the time. In this video, I explain exactly why I built my own 60ft tilt-over mast using scaffold poles instead of going down the traditional tower route.

Having used lattice towers before, I know how good they can be. But there’s a side to them people don’t always talk about – transport, foundations, maintenance, cost, and what happens when things go wrong. This build solves a lot of those problems in a surprisingly simple way.

This mast is fully single-handed. I can raise and lower it in minutes, it’s built from readily available materials, and if something breaks, I fix it the same day. No waiting for parts, no specialist sections, no heavy machinery required beyond the initial setup.

I also walk through the basic geometry behind the system – a falling derrick design. Once you understand that, the whole thing becomes much less mysterious than it looks at first glance.

Cost-wise, the entire system comes in at under £1,000 (excluding the rotator), spread over time. Everything can be transported and handled by one person, and the installation is completely reversible – important when you’re working in a field that may one day return to its original use.

The final sequence shows the mast being raised – something I never get tired of watching. There’s something quite special about seeing it go up smoothly and quietly at the press of a button.

If you’ve ever considered putting up a tower, or thought it was out of reach, this might give you another option.

DX Commander products: https://dxcommander.com

Chapters
00:00 Why not a lattice tower?
01:30 Real-world downsides of towers
03:00 Why this mast works better for me
05:30 How the falling derrick system works
07:30 Cost breakdown
09:01 Raising the mast

Another storm brewing…

When my 60 ft (18 m) antenna mast came down in a storm, I had a theory… Actually – everyone had a theory.

– Too many guys.
– Not enough guys.
– Angles too steep.
– Rope stretch.

Turns out… we were all wrong. In this video I rebuild the tower and explain what really happened — including the exact failure that brought the whole system down.

We also look at:

– Guy angles and geometry
– Wind loading and bending moment
– Why rope stiffness matters more than strength
– Why the top section behaves differently
– And how the rebuild improves the system

The original trigger was simple. The way it failed… wasn’t.

👉 One missing shackle pin started it.
👉 Rope stretch finished it.

We’ve now rebuilt the tower, upgraded the guys, and the next step will be switching to Dyneema.

If you enjoy practical antenna building, real-world engineering, and learning from mistakes — you’re in the right place.

73, Callum M0MCX.

Buy here: https://dxcommander.com/product/free-worldwide-shipping-easter-expedition-antenna-kit-copy/ Limited Easter run – once they’re gone, free shipping ends.

WHAT’S INCLUDED
– DX Commander Expedition antenna kit (80m–6m capable)
– Free worldwide shipping (limited time)
– Extra 100m DX10 wire included
– All parts included – nothing missing

IMPORTANT
– Import duty / VAT may apply depending on your country
– Collected by courier (UPS) at delivery
– This is standard for international orders

BUILD VIDEO

INVERTED L BUILD

TOM’S PORTABLE SETUP
https://youtu.be/xJnN5nAIFG8

A curious line of thinking… What if Stonehenge wasn’t built to transmit anything at all? What if it was designed to remove noise?

In this video, we explore an unusual collaboration between Dr Arnold Schwarz (Technical Institute of Munich) and Professor Barker (OU Milton Keynes), and a series of experiments that led to some rather unexpected results.

Topics touched on include:

multi-channel correlation
atmospheric noise cancellation
low-noise receive systems
ground-referenced signal stability

If you’ve ever experimented with LoGs or other receive antennas, some of this may feel… oddly familiar.

That said… the discussion around noise, correlation, and receive antennas is very real. The “research”, professors, field work, and documents were created using AI tools and a slightly overactive imagination. Filmed and published on April 1st. If you made it this far without raising an eyebrow… well done.

And if you spotted the “anomaly”… even better.

In this episode we take the delta loop from Part 5 and convert it into a vertically polarised delta loop. Using MMANA-GAL, we build and model a simple mono-band loop and explore how its radiation pattern compares to a vertical antenna.

In this video we:

• Convert a horizontal loop into a vertical loop
• Position the feedpoint for ~100Ω impedance
• Model a quarter-wave matching section (75Ω)
• Use wire scaling to tune the antenna
• Compare low-angle performance (5° take-off)
• Observe the bi-directional radiation pattern

You’ll also see how a vertical delta loop can behave a bit like a broadside array, producing useful gain in two directions.

This is a simple, practical example of how antenna shape and feedpoint position directly affect performance.

In the next episode we’ll move on to modelling an End-Fed Half-Wave (EFHW) antenna.

Software used

MMANA-GAL (Basic version)
Free download:
http://gal-ana.de/basicmm/en/

Model files used in this series

All MMANA-GAL antenna models used in these tutorials can be downloaded here:

📁 https://mega.nz/folder/EnoXlTQL#Iuq-TqnW7ZglzkJMEIk59w

This folder will be updated as new videos in the series are released.

Full Video Playlist

📺 https://www.youtube.com/playlist?list=PLcC64tNkZB7zl-6HKJ5ihuSH3-22IX6kq

If you want to follow the whole modelling series, subscribe so you don’t miss the next episode.

The mast came down… but not for the reason I expected. In ~50 mph winds I was convinced something structural would fail – aluminium, couplers, shackles. No. Instead, everything survived. The real issue? Rope stretch!

It turns out poly rope can elongate far more than you think under load (22%). Once the top guy stretched far enough, the geometry flipped and the mast effectively pulled itself over. No snap, no bang – just a slow, graceful failure.

In this video I strip it back, work out what actually happened, and start the rebuild properly. We look at guy tension, stretch vs stability, and why temporary rope is useful for prototyping before moving to Dyneema.

A great reminder that in antenna building, the weak point isn’t always where you expect — and sometimes failure is the best teacher.

Rebuild Part 2 coming next week. Stay tuned!

Today I’m tuning the Yagi after raising it another 6–7 metres on the upgraded mast. As expected, the resonant frequency has shifted higher, so the job is to bring it back down into the right part of the band. Rather than starting again, I’m extending the elements slightly and trying a simple little loop on the ends – partly for RF behaviour, partly because it just feels like a neater way of doing it. This "loop fix" is not about current heating the ends – it’s voltage trying to escape. A sharp tip concentrates it like a lightning rod. Add a loop and suddenly nothing to see. Another way of looking at this is that at high power, a sharp element tip is basically trying to turn into a tiny plasma ball (corona discharge). If we round it off, it never gets to form = lot less heat.

This video covers:

dropping the tower again (of course…)
measuring and extending the driven element and reflector
a quick-and-dirty field method using an SWR calculator
checking and correcting alignment on the beam
dealing with wind, rope stretch and the realities of working at height
and a first check of the new resonance once it’s back up

There’s also a bit of discussion around:

why height changes tuning
why every part of a mast system is effectively a single point of failure
and how small gains (a few dB here and there) all add up to a noticeably better station

I’ve slightly overcooked the length – but it’s close enough for now and easily trimmed later.

Next job will be building a proper choke to replace the temporary one, and squeezing a bit more performance out of the system.

Thanks for watching – see you on the next one.

PS : the "loop fix"… It’s not current heating the ends – it’s voltage trying to escape. A sharp tip concentrates it like a lightning rod. Add a loop and suddenly nothing to see. Another way of looking at this is that at high power, a sharp element tip is basically trying to turn into a tiny plasma ball. If we round it off, it never gets to form. Easy. Callum.