MFJ-2990 A JOURNEY WELL DONE:

Author: Marius Lubbe ZS1ML
www.learnminds.co.za 

The Complete Story of my MFJ-2990 Antenna, MFJ-1903 Tilt Base, MFJ-2910 Switching Unit, and Radial Installation

Introduction
Greetings, fellow radio enthusiasts and curious minds! Today, I’m going to share with you an epic saga: A comprehensive, step-by-step guide on how I and a few very valuable friends, successfully installed the MFJ-2990 Antenna, complemented by the MFJ-1903 Tilt Base, MFJ-2910 Switching Unit, and a meticulously laid out radial system. This isn’t just a tale; it’s a manual, a guidebook, and a narrative of adventure. So, make yourself a cup of tea or coffee, and let’s dive into this journey!

CHAPTER 1: THE PRE-INSTALLATION CHECKLIST
Site Survey: The Quest for the Perfect Location
The first step in any great adventure is preparation. I took a tape measure and a compass app on my smartphone and scouted my property. The MFJ-2990 is a towering 43-foot (13.1 meters) antenna, so I needed a spot that was not only spacious but also far from any power lines and my wife’s cherished rose bushes. After a thorough survey, I found the ideal location. It felt like the universe aligned itself to say, “This is the place.”
Gathering Tools and Materials: The Treasure Chest
Armed with a list, we gathered all the essential tools and materials:
• Adjustable wrenches: For those stubborn bolts and nuts.
• Screwdrivers: Flathead and Phillips, each has its role.
• A shovel: For digging the foundation hole.
• Conductive grease: To ensure excellent electrical contact.
We neatly arranged these tools on a workbench, like a pilot preparing for takeoff.
Safety Gear: The Pilot’s Pre-Flight Checklist
Safety isn’t just a word; it’s a mantra. We equipped ourself with:
• Heavy-duty gloves: To protect my hands from any scrapes or cuts.
• Safety goggles: Because eye protection is no joke.
• A hard hat: You never know when a falling object might surprise you.

CHAPTER 2: INSTALLING THE MFJ-1903 TILT BASE
Digging the Hole: The Foundation of Success
With shovel in hand, we dug a hole approximately 3 to 4 feet (0.91 to 1.22 meters) deep. we used a spirit level to ensure the hole’s sides were as straight as possible. This depth would provide the stability needed for the towering antenna.

Pouring the Concrete: Setting the Stage
After the hole was dug, we mixed ready-mix concrete in a wheelbarrow, following the manufacturer’s instructions. I poured the concrete into the hole, making sure it had a diameter of about 10 inches (25.4 cm). We smoothed the top with a trowel and let it set for a full 48 hours.

Installing the Base Bracket: The First Building Block
Once the concrete had set, it was time to attach the base bracket. We aligned it with the support pipe and used U-bolts to secure it. We tightened the nuts with an adjustable wrench, double-checking to ensure it was level.

Attaching the Tilt Bracket: The Pivotal Moment
The tilt bracket was next. We slid it onto the base bracket and inserted the bolts. We tightened them but not too much; some wiggle room was necessary for the next steps.

CHAPTER 3: THE RADIAL SYSTEM
Choosing the Wire: The Veins of the System
For the radials, I used 1.5mm electrical house wire. I cut them into lengths of about 3 meters each, totalling 100 meters of wire. Enough for a ¼ wave on 160M.

Laying the Radials: The Spider Web
I laid these radials on the lawn in a 90-degree arc around the base of the antenna. I used small wire stakes to keep them in place temporarily.

The Natural Camouflage: A Lawn’s Embrace
Within a month, the grass grew over the radials, effectively camouflaging them. I’ve been mowing my lawn as usual, and you’d never know there’s a complex radial system beneath it.

CHAPTER 4: ASSEMBLING THE MFJ-2990 ANTENNA
Attaching the Antenna: The Crowning Jewel
With the base and radials in place, it was time to attach the MFJ-2990 antenna to the tilt bracket. We lifted the antenna and aligned it with the holes on the tilt bracket. Using the provided bolts and nuts, we secured the antenna in place.

Raising the Antenna: The Moment of Glory
Using the MFJ-1903 Tilt Base’s tilting mechanism, we carefully raised the antenna to its vertical position. It was a two-person job, and as the antenna ascended, I couldn’t help but feel a sense of awe.

Securing the Setup: Lock and Key
Once the antenna was vertical, we tightened all the bolts and nuts to lock it in place. We double-checked every connection to ensure it was secure. We also decided to add two sets of guy ropes, as where we live in Cape Town, South Africa, the area is not called the Cape of Storms for nothing.

CHAPTER 5: THE MFJ-2910 SWITCHING UNIT
Unboxing and First Impressions: A New Toy
When the MFJ-2910 Switching Unit arrived, I was ecstatic. I carefully unboxed it and inspected the unit. It was robust and well-designed, promising a range of tuning options from 6m to 160m by accessing the coils inside the unit. We decided to let it alone for the moment and see to what extent the MFJ factory have tuned it already, before trying to fine tune the various band units.

What is the MFJ-2910 Switching Unit?
After unboxing the MFJ-2910, it’s worth taking a moment to understand what this marvellous piece of equipment is. The MFJ-2910 Switching Unit is essentially a multi-balun and two sets of coils, accessed by a very clever system of relays, accessed from a Coax bias-T unit in the shack that sends power to the correct relay, and that, then allows you to tune your antenna to various bands. It’s designed to work seamlessly with the MFJ-2990, offering a range of tuning options from 6m to 160m. This unit is a game-changer for anyone looking to explore multiple bands without the hassle of manual adjustments. No spoilers, but this is not a pipe dream.

How Does the MFJ-2910 Work?
The MFJ-2910 is not just a simple piece of hardware; it’s a well-engineered device that makes your life easier. It operates by matching the impedance of your antenna to your radio, ensuring that you get the best possible signal. The unit comes with a set of switches that allow you to select the band you wish to operate on. Once you flip the switch to the desired band, the unit automatically adjusts the impedance, making sure your antenna is perfectly tuned.
The MFJ-2910 is capable of handling up to 1.5 kW, making it suitable for most amateur radio operations. It’s also incredibly durable, built with high-quality materials that promise long-lasting performance.

Installation and Operation: The Final Touch
Installing the MFJ-2910 was a breeze. We connected it to the antenna using high-quality RG213 coaxial cables, ensuring a secure and stable connection. We then used cable ties to neatly organize the cables, and an irrigation pipe underground, making sure everything looked tidy, and was secure from the elements.
Operating the unit was as simple as flipping a switch. With the MFJ-2910, tuning to different bands, became a matter of seconds, not minutes.

My very valuable helpers,
Left: local handyman Siphiwo (Patrick) Mgcodo and on the right: elmer and good friend Dr. Emil Böhme ZS1XB

CHAPTER 6: FINAL CHECKS AND CELEBRATIONS
SWR Testing: The Seal of Approval
With the MFJ-2910 now part of my setup, I conducted another round of SWR tests. I used my trusty NanoVNA H2 that I had upgraded to after the original NanoVNA became a staple of my antenna work. As I am getting older, I definitely appreciate the bigger screen on the NanoVNA H2. The results we got from scanning every possible band were much better than expected, confirming that the MFJ-2910 was doing its job splendidly.

See all the SWR sweeps at the end of the article:

The Maiden Voyage: First Contacts
Finally, with everything in place, I powered up my radio and made my first contacts on multiple bands, thanks to the versatility provided by the MFJ-2910. The sense of accomplishment was overwhelming, and the performance was nothing short of exceptional.

Conclusion: The Journey’s End
And there you have it; a detailed, step-by-step account of our journey in setting up the MFJ-2990 antenna system.
It was a project filled with challenges, learning experiences, and ultimately, immense satisfaction. If you’re planning a similar adventure, I hope this guide serves you well.

AS A FINAL NOTE, I CAN ONLY RECOMMEND THIS ANTENNA IN THE HIGHEST POSSIBLE MANNER. IT IS A STURDY, WELL-MADE AND EXTREMELY CAPABLE PIECE OF KIT.

Until next time, keep those signals strong and those SWRs low. 73!

Note: Always refer to the manufacturer’s guidelines for the most accurate and up-to-date information.
The following SWR sweeps were done before final adjustments to the matching unit, the MFJ-2910 was undertaken. Remember that even at this very good performance level, it is recommended you use a MFJ tuner like the fabulous MFJ-993B. It finds this an easy task and makes operating on all bands an absolute pleasure. We will revisit all these band and using the manual tuning of the coils on the matching unit (multi-balun), try to get each band as close to 1:1 as possible.

Just for fun I took an SWR sweep on 2M, can you believe it? It should be impossible, however here before your very eyes is the evidence.

6M sweep with the NANO VNA H2 and NanoVNA Saver. Out of the box and direct from the MFJ, without any fine tuning. We will definitely go back to this one for some fine tuning on the matching unit.

10M sweep, out of the box and direct from the MFJ, without any fine tuning. Looking good!

12M sweep, out of the box and direct from the MFJ, without any fine tuning. Quite usable but, some fine tuning needed.

15M Sweep, out of the box and direct from the MFJ, without any fine tuning. Needs some attention by manual fine tuning the matching unit coils.

17M Sweep, out of the box and direct from the MFJ, without any fine tuning. Quite usable as is.

20M sweep, out of the box and direct from the MFJ, without any fine tuning. We will definitely go back to this one for some fine tuning on the matching unit.

30M sweep, out of the box and direct from the MFJ, without any fine tuning. We will go back to this one for some manual fine tuning on the matching unit.

40M sweep, out of the box and direct from the MFJ, without any fine tuning. Usable as is.

60M sweep, out of the box and direct from the MFJ, without any fine tuning. This can use some manual fine tuning of the matching unit.

80M sweep, out of the box and direct from the MFJ, without any fine tuning. Maybe give it some attention by manual fine tuning the matching unit coils.

160M sweep, out of the box and direct from the MFJ, without any fine tuning. When fine tuning we will attempt to bring it even lower.