Category: DX Commander

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.

After getting the first section up in Part 1, I go back over everything, tighten it all down, fix a few small issues, and then push on to extend the mast to its full height with the Yagi on top.

This part includes:

– dropping the tower again to make final adjustments
– trimming the top section and correcting clearances
– adding the third pole and refining the guying geometry
– routing coax through the mast
f- itting connectors and sorting out a few “field engineering” surprises
a- nd working through the reality that every single part of this system is a single point of failure

There’s a moment where you realise the scale of what you’ve built – and also that there’s no going back once it starts going up.

On the Sunday, we clear back trees to give the antenna space it deserves… and then comes the first proper full lift to around 19 metres with the Yagi on top.

I’ve left that section to breathe a bit, with some rather atmospheric music – because honestly, watching something like this go up feels a bit special.

Final tweaks include:

– correcting the magnetic sensor orientation
– tightening clamshells and hardware
– checking the new rotator behaviour
– and noting the shift in resonance now the antenna is at height

The result?

Around 2.5–3 dB improvement from the extra height alone — which in radio terms is a very real step forward.

There’s still more to do, but the tower is now properly up and working.

We’ll do some on-air testing and live streams next to see how it performs in the real world.

Thanks for watching.

00:00 Back on the tower – checks and adjustments
01:15 Dropping the mast again
02:13 Cutting and correcting the top section
03:18 Preparing for the third pole
05:17 Guying and geometry setup
08:02 First partial lift and alignment
10:43 Feeding coax through the mast
12:19 Fitting connectors and testing
17:18 Final prep before full lift
18:50 Tree clearance needed
19:24 Sunday – clearing space
22:42 Final lift and Monday checks
23:45 Fixing sensor and tightening hardware
25:19 Height gains and performance discussion

Today’s job is a proper step forward on the tower rebuild. In this first part, I strip down the original mast, fit the new GS-2800 rotator, correct some long-standing geometry issues around the hinge point, add a substantial insulated section, and begin rebuilding the tower with heavier-duty hardware and a new plan for the guying.

The long-term idea here is not just a stronger lift-up mast for the beam, but a structure that can eventually serve double-duty as part of a 160m vertical as well. That means thinking ahead now – insulation, support sleeves, thrust bearings, couplers, turnbuckles, shackles, and how the whole thing behaves while going up and down.

This is very much real-world prototyping in the field:

– taking the old mast down
– removing the beam
– rebuilding the lower section
– fitting the new rotator
– correcting the hinge arrangement
– testing the first section with revised guying
– adding the second steel pole
– and finally carrying out a cautious test lift

I also talk through the design thinking as I go – including why I’m changing to Dyneema guys, why I’ve moved away from the original arrangement, and how I’m trying to make the whole system stronger, smoother and more repeatable.

The camera gave up near the end, so the final lift is shown via the field camera. Part 2 will continue with the next stage of the tower build, final alignment, and getting the extended mast up to its finished working height.

Thanks for watching.

00:00 Tower upgrade begins
00:38 Building the insulator section
03:30 Dropping the old mast
06:49 Removing the beam and stripping down
10:50 Shim and rotator fitting
11:55 Correcting the hinge point
13:22 Mounting the GS-2800
14:43 New guying plan explained
17:34 Rebuilding the lower section
25:25 Next day – upgraded hardware
30:27 Rethinking the design
32:56 Reworking the guy anchors
36:55 First section back up
42:32 Plan for Dyneema guys
51:57 Heavy-duty coupler and second pole
54:40 Final test lift

#hamradio #amateurradio #tower #rotator #dxcommander

Today I get the Yaesu GS-2800 and G-450 rotators working with the Rotator Genius for remote, network control.

This turned into a bit of a saga… but we got there in the end.

In this video I cover:

– How Rotator Genius actually drives DC rotators (2-wire vs 3-wire confusion)
– Correct wiring for GS-2800 and G-450 (pins and setup)
– Bench testing before going up the tower
– Magnetic sensor install and alignment
– Dip switch settings (and how the manual can trip you up)
– Speed control and voltage considerations
– Getting two rotators working on one system

The goal here is simple: allow multiple stations to control different towers over the network without conflict.

This wasn’t a plug-and-play job – it took a few days of checking and thinking of trial and error to get right. If you’re setting up Rotator Genius, this should save you a fair bit of time!

00:00 Overview and plan
02:19 Wiring breakthrough (2-wire control)
03:10 Dip switch issues
05:32 Adding second rotator (G-450)
10:27 Field testing
11:47 Sensor install
14:23 Software control and presets
16:15 Final thoughts

In this episode we move away from verticals and start modelling loop antennas.

Using MMANA-GAL, we draw a horizontal delta loop and explore how it behaves compared to a vertical antenna.

Along the way we also look at how ground conditions affect antenna performance, and why antennas near salt water can perform dramatically better.

In this video we:

• Benchmark a vertical antenna at low take-off angles
• See how changing ground conductivity affects performance
• Draw a horizontal delta loop using the wire editor
• Place the feedpoint and model a 4:1 balun
• Use wire scaling to tune the antenna to the correct frequency
• Compare the far-field plots of a loop and a vertical

You’ll also see how loop antennas behave on multiple harmonics, making them useful multiband antennas.

In the next episode we’ll convert this into a vertically polarised delta loop and compare the radiation patterns again.

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.

In this episode we take the ground mounted vertical from Part 3 and add elevated radials to see how the antenna behaves.

Using MMANA-GAL, we model a simple vertical and experiment with different radial configurations to see how they affect the far-field radiation pattern.

In this video we:

• Start with a basic ground mounted vertical
• Add two elevated radials
• Compare radiation patterns using the Compare function
• Add additional radials and experiment with geometry
• Raise the antenna and slope the radials downward
• Observe how the low-angle radiation changes

The goal here isn’t deep theory – it’s learning how to draw the antenna and observe what happens when you change the geometry.

You’ll also see how elevated radials can slightly improve low-angle radiation, which is important for DX performance.

In the next episode we’ll move on from verticals and start looking at loop antennas.

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.

Thanks to Regin (OY1R) and Stian (LB5SH) for arranging this. You may have heard them previously calling in to my streams with their home calls in the past. With the help of WhatsApp to get a sked, we made it. Just for fun guys, I don’t really collect DX Entities.

It takes a whole community to make these things happen and everyone should be proud, the operators, the major sponsors and of course the small donations from the average ham. I know it goes a long way.

You can hear Stian calling me as 3Y/LB5SH and that starts here:

I have to say, the team this time around have done an awesome job. I think they almost cleared 100,000 QSOs and a great boost and focus for many.

See https://3y0k.com/

Thank you to the team on Bouvet Island for this amazinig experience for the 100,000 or so QSOs they made before packing up.