Configuring your DX HOA Flagpole Antenna System | Ham Radio Antenna

by Greyline Performance

How to Correctly Configure the Greyline Flagpole and Vertical Dipole Antenna Feed System

Hint: Coax from your shack, then RF Choke - ATU (Remote Tuner) - HF Antenna

We do get a fair number of inquiries that start out saying, "How do I feed the Greyline Flagpole correctly?" and it's easy to understand why, as the answer certainly is not intuitive.

Most of us think we can plug a 50 Ohm coax into an antenna out of the box and we're off to the races breaking pile-ups and feeling loud! Well, high-end plug-and-play is the general goal of our product design but it doesn't work quite that simply, but it's close! 

There is a sequence to the "feed system" that is required for higher performance. Tune in below for more information from one of the antenna sages of our time, Mr. John Portune, perennial QST Magazine Award-Winning Author and career engineer who was kind enough to share his wisdom on the topic.

 

Correctly Configuring the DX Flagpole Antenna, Tuner, and Balun

It is a common belief that one must “ground everything.” This is NOT true for the Greyline DX Flagpole Antenna System. The antenna must “float” electrically above ground. The reason is basic. Like a common wire dipole (like a wire dipole in the tree) the flagpole antenna is a balanced antenna.

The Greyline HOA DX Flagpole Antenna is an electrical-half-wavelength vertical dipole

Most verticals work against ground radials and are fed unbalanced at the base. The flagpole must not be fed unbalanced. It is an electrical-half-wavelength vertical dipole. Both ends are insulated from the ground and the off-center (OCF) feed point must be provided with a balanced feed.

Therefore, the tuner must also have a TRUE balanced output.

However, most modern tuners are unbalanced by design. The main output is grounded via the shield of the SO-239 output connector. Some commercial tuners do have an output labeled as balanced. In most cases, a balanced output is only simulated by an internal voltage balun. This method cannot be used with the flagpole antenna.

The ONLY satisfactory way to provide a true floating balanced output from an unbalanced tuner is to insulate it from the ground. Then to make it “float,” a 1:1 current choke must but placed in the coax directly ahead of the tuner. (This means to place it on the radio side of the tuner, for those of us who are blessed with laymen term knowledge levels)

 

Figure 2: An example that works well is this "balun", or RF Choke more appropriately, by Palomar Engineers called the BA-2 ferrite sleeve, 1:1 current choke balun, with 5 Mix 31 Ferrite Beads in series, installed on a short coax pigtail. (Heat-shrink tubing is removed for viewing).

Note: Greyline provides these 5 snap-on chokes by default with ALL antenna purchases)

Update: It's believed this model is discontinued by Palomar, but you get the idea. Also, for more than 100 Watts, consider 7-9 units of Mix 31 beads of this size as a good starting point.

Tip: Greyline offers various forms of RF Choking on our website, from the two versions of the 3500 Watt military grade Maxi Choker, the 500 Watt Mini Chokers popular for both Choking and QRN mitigation, and several Ferrite cores and snap-on cores for your DIY RF Choke needs. 

Any true commercial or home-brew current balun of sufficient power-handling capacity is acceptable. Make sure, though, that it is a current balun; many are not marked. 

Lastly, it is essential to mount the tuner with the balun on an insulated surface or pole nearby. Do not lay them directly on the ground or connect them to the ground.

Many of our customers find success 6 inches or more above ground mounting on a wooden stake or PVC pipe next to the antenna. Thanks, John for your perspective. That makes things much easier to understand.

 

Customer Install Series Rob in Colorado's Journey with a Greyline 20' DX Flagpole in his HOA. This is a well-written How-to for anyone wanting a walk-through of the installation steps with commentary and photos.


Pro Tip: Building Sections, from the ground up

The thicker wall sections are installed lower and the lighter ones for the upper sections. 

  1. The lowest section is meant for ground insertion. It matches the length of the PVC
  2. The Lower Dipole, with the slotted insulator
  3. The Feed-point Section with the two round holes in the insulator (for your separated ladder line wires, one per hole. Connect one wire to the bolt upward on one side, and the same downward on the other side)
  4. The Flag Cleat Section is next. This one exhibits 2 holes used for the Flag Cleat (if applicable)
  5. The Middle Sections are all the same going up the pole with the transition sections on the upper side of the tubing. 
  6. The Top Section's upper side has no bolt holes


Pro Tip: Feeding the Dipole sections

Separate the two ladder line wires at the feed point with approximately 6 inches of now single wire each and pull them through, one per hole left and right, for example. This is a great time to be certain that you know which wire is which. You'll want to connect the Upper Dipole sections (the longer radiator) to the center coax conductor. You can do this by eye and marking the wire on each end or by using an Ohm meter to check continuity for those areas.

Reminder: If you are using an ATU at the base of the vertical antenna, please consider raising the tuning circuit at least 6 inches off of the ground, as well as the ladder line feed, and RF Choke as they too must be above ground. This is all part of the antenna system until we reach the RF Choke and Coax back to the shack.

Let us know your first impressions. Remember, Ham Radio is fun again. Pass it on...

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+ Includes All Kits (Ground kit, Feed kit, Flag kit)
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How to Order a Flagpole Antenna, checklist.

 

 

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We hope you enjoyed this story and were entertained by it. Maybe you remember a similar story in your youth. GL finding your rare ones. Ham Radio is fun again! Pass it on...

 

WHAT CUSTOMERS ARE SAYING:

  • "Real DX 160-6M at my HOA"
  • "4 Band DXCC in 3 months at my HOA."
  • "So pretty my XYL approves!"
  • "If I can hear it, I can work it."

Our Mission:
At Greyline, it's our Mission to serve you by offering higher-quality products that truly enhance your Ham Radio experiences. Standing up to Hurricanes is just a bonus. Antennas that work Real DX and that the ladies can love too. Now that is smarter, stronger, and more elegant for you and your family's security. We are delighted to serve you.

Let's enjoy the adventure, together. Until next time...

73 Greyline Performance
Ph. 435-200-4902 


Ham Radio is fun again! Pass it on...

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This survey reads like a Q&A of how to turn your 20-24' Flagpole Antenna into an 80-160M Real DX antenna for those using the lower impedance range (low cost) tuners.  

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    For your entertainment, a ham radio poem:

    In the world of ham radio, Connections can be hard to grow. But with Greyline Performance gear, The signal becomes crystal clear.

    The flagpole antenna stands tall, Sending out signals with a powerful call. And with his wife's approval and a smile, The ham operator can chat for miles.

    Through the airwaves they converse, A world of communication they immerse. Thanks to Greyline Performance's aid, Their passion for ham radio never fades.

    From mountains high to valleys low, They connect with others they've yet to know. And as the sun sets on another day, They keep talking with much to say.

    So here's to Greyline Performance's brand, And the ham radio lovers across the land. May the flagpole antenna never fall, As they continue to connect with one and all.

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