A simple job that somehow took all afternoon! Today I’m re-tuning the 160 metre leg of my 80 / 160 fan dipole — dropping the resonance from 1.94 MHz down to 1.85 MHz where the amp is happiest.
I’ll show how longer = lower (it still catches me out sometimes!), explain why the UK full-power segment matters, and talk a bit about impedance, quarter-wave 75 Ω sections, and matching tricks for low NVIS dipoles.
Original Build: https://youtu.be/PV5GdAZ1nfo
Expect the usual chuckles, dog balls, and unexpected wander into the woods…
Gear used: DX50 Kevlar wire, 75 Ω coax, analyser, and a mug of tea.
4-Square Antenna: Today’s mission: get everything grounded, bolted, and ready before the big 4-Square tune-up!
I realised I’d tuned the array for best SWR, not for X = 0, so before I fix that – we need to sort the tower, coax, and winch area – all with proper grounding.
Tasks:
👉 Hammer in new copper rods and bond them to the mast and cabinet
👉 Mount the winch battery cabinet on C16 timbers
👉 Add a grounding plate and lugs for coax feeds
👉 Tidy the wiring for the new Multi-2 setup
👉 Talk about why my ACOM amp saga still isn’t over 😅
If you enjoy real-world ham-radio builds, with mistakes, fixes, and learning as we go — you’ll love this one.
Next video: the final 4-Square tuning and on-air test!
00:00 – Intro & The 4-Square Mistake
00:35 – Why X=0 Matters More Than SWR
01:00 – Grounding Before Tuning
02:20 – Cutting Timbers for the Winch Cabinet
03:40 – Mounting the Heavy Cabinet
05:20 – Planning the Dead-Man Anchor & Winch Setup
06:15 – Hammering in the Ground Rod
07:00 – ChatGPT Told Me to Do This?!
08:10 – Grinding & Prepping the Cabinet Backplate
09:00 – The AOM Amplifier Saga Continues
11:00 – Drilling, Tapping & Making Grounding Plates
13:00 – Connecting the Ground Straps
15:20 – Testing Tower Bonding & Rotator Ground
17:00 – Thinking About the Falling Derrick Design
18:40 – ‘Invisibleising’ the Tower (Grounding Strategy)
20:00 – Checking Every Connection
21:00 – Final Ground Tests – It’s All Bonded!
22:00 – Wrap-Up & Plans for the Next Tune-Up
Important engineering upgrades in the antenna field – improving the foundations for the new lightweight tower, installing a Dead-Man anchor for the electric winch, and grounding the tower to the radial network.
The day starts with a look at the original winch post and the maths behind its load capacity. Although the first anchor could handle around 200 kg, the mechanical advantage of the increased height on the falling-derrick (not a “gin pole”!) introduced additional torque and stress. The solution? An engineered Dead-Man anchor buried crosswise – the same principle used in bridge and harbour design.
We pour, cure, and backfill the new anchor, review older ones, and make key decisions about reinforcement and concrete volume. Then it’s on to grounding: bonding the radial field directly to the tower base and cabinet using copper strap and self-amalgamating tape for long-term corrosion resistance.
Along the way, we cover:
➡️ Calculating load and fulcrum points on a small tower system
➡️ Practical tips for mixing and pouring small-batch concrete outdoors
➡️ Grounding and bonding strategy for multi-antenna installations
➡️ Managing radials around automated mowers
➡️ Handling real-world compromises when parts or materials are missing
Also featuring: spontaneous design decisions, visits from Junior and Django, drill bit snapping mid-hole!
By the end of the day, all anchors are upgraded, the tower base is bonded, and we’re ready for the next phase – raising the lightweight tower in time for CQ Worldwide.
0:00 – Intro & plan of attack
0:45 – Why the old anchor wasn’t enough
2:00 – Mixing and pouring the new concrete
6:00 – Upgrading existing anchors (and some decisions!)
8:00 – Explaining the Dead-Man concept
10:00 – Improvised engineering & “Callum moments”
13:30 – Dogs arrive on site
16:00 – Drilling, bending & building the Dead-Man anchor
20:00 – Grounding the tower and radials
23:00 – Review & next-phase tower talk
📡 More DX Commander builds:
➡️ [Signature 12.4 Setup and Test]
➡️ [40 m 4-Square Explained]
➡️ [Remote Station Build Series]
60 MPH STORM vs DX Commander Antennas - Destruction Test!
Caught in 60 mph gusts at Holly Farm. Watch the DX Commander Signature 9s, Rapides, and a Signature 18 bend, whip and hold firm through the storm. Nothing failed — just real-world proof these antennas can take it.
Remember the shock-cord "trick" I added to the Signature 18? Here it is: https://youtu.be/sIRSW5qJwD8
INSANE Signal Strength! COMTEK 40m 4-Square Antenna from DX Engineering
Today we’re commissioning the COMTEK / DX Engineering 40m 4-Square Antenna system here at DX Commander HQ. This is one of the most powerful setups for the 40m band — insane signal strength and front-to-back ratio. In this video I’ll take you through the build, wiring, tuning, fault-finding, and finally the moment of truth… including working Japan at +20dB over S9!
If you’re interested in serious DXing or contesting on 40m, the 4-Square is a game-changer.
Thanks to:
Tim Duffy K3LR and the DX Engineering team for the Comtek
Stefano at Messi & Paoloni for the 75 ohm coax
Martin and Mike for radial work and installation help
👉 Subscribe for more antenna builds, on-air tests, and DX Commander behind-the-scenes!
0:00 – Introduction & overview
0:20 – What is a 4-Square?
1:00 – Direction switching explained
1:45 – The COMTEK / DX Engineering controller box
3:00 – Wiring up & dummy load
4:45 – Software control with OM module
6:30 – Clickity-click relay tests
9:20 – Thank you DX Engineering
10:30 – Dummy load install
12:00 – Coax routing challenges
14:00 – Phasing line connections
16:30 – Trimming & tuning elements
19:00 – Resonance checks & adjustments
23:00 – Chat with Tim Duffy K3LR
24:30 – First tests & fault-finding
27:30 – T-piece troubleshooting
30:00 – Fixing a duff PL259
32:20 – Retesting antenna
33:15 – LIVE QSO with Japan (+20dB over S9!)
35:10 – Final thoughts: cost, complexity, and performance
160m / 80m Massive Fan Dipole - Full Build & Test - from Scratch
This is my biggest antenna build yet! A full 160m / 80m fan dipole — from scratch, all the way through to WSPR testing.
In this video you’ll see:
✅ Preparing and painting the poles
✅ Building the dipole centre and elements
✅ Coax, balun and choke setup
✅ Raising the mast (the epic lift 🙂
✅ Tuning and first SWR tests
It’s rare to see a compact 160m solution paired with a full-sized 80m dipole, so I wanted to document the entire process in detail.
If you’re into low-band antennas, DIY builds, or just enjoy big projects coming to life, you’ll love this one.
📡 Subscribe for more antenna builds, ham radio experiments, and contest action.
💬 Drop a comment if you’ve ever tried 160m — I’d love to hear what worked (or didn’t!) for you.
0:00 – Teaser – The big lift (hook)
0:12 – Preparing the Poles – Painting, fitting, grinding, ramming sections together
6:31 – Planning the Dipole – Measurements, wire lengths, horseshoe layout
9:38 – Cutting & Prepping Wire – Kevlar cord, foldbacks, dipole centre
15:33 – Coax & Balun Setup – Patch leads, choke discussion, memories of Barry
21:00 – Coax Assembly – Measuring, cutting, connectors, testing continuity
31:20 – Adding 80m Legs – Fan dipole build begins
34:00 – Matching & Impedance Talk – 75Ω quarter-wave match explanation
36:05 – Mounting & Bolting Mast – Drilling, washers, test-fit
42:50 – Securing Mast – Bolts, levelling, wide shot
48:40 – Next Day Setup – Tensioning, knots, wind test
51:00 – 160m & 80m Alignment – Galvanised fixings, lifting elements
56:13 – 80m Wire Install – Cleats, pilot holes, tensioning
1:00:00 – Coax & Final Tension – Routing, connectors, self-amalg tape
1:03:30 – Testing & SWR – Adjustments, bandwidth discussion
1:05:30 – Wrap Up – Sign-off and next project
1:06:27 – Easter Egg – Intentional error / correction
