Radiation Patterns for Greyline Antennas mounted at Ground Level, House Eave, House Peak, and Tower Tops
How does the 20' Flagpole Antenna, HF Vertical Dipole play at varying install heights and locations?
We receive questions from our customers such as "Can I mount this on my roof? Near a tree? or The bulkhead on the water?" Let's take a look at some graphics reflecting the various Bands and Performance patterns at various mounting heights, and scenarios. We think you can read between the lines for other ideas. We have so many customers
As a simple visual reference, the below performance plots can help guide your expectations by illustrating the various antenna heights one might consider for the 20-foot HF vertical antenna and HOA Flagpole Antenna:
1 ft. (ground level) - red
10 ft. (house eave height) - blue
25 ft. (house peak height) - green
50 ft. (tower top height) - orange
Antennas typically enjoy height. For most of us, ground mounting is the only option, for others, there are supports we could experiment with above ground.
These graphs look at the comparison of various installation heights such as Ground level, 10 feet, 25 feet, and 50 feet high using a 20' Greyline Flagpole Antenna or Vertical Dipole Antenna, common with our customers. These four plots show us the assumed pattern (angle and gain) on the four highly popular Ham Radio band segments of 10, 20, 40, and 80M.
So, looking closer at the 10M plot we see the four called out heights in their corresponding colors. Orange is the 50' height and red is the ground-level install height which is most common.
A couple of observations:
1. Look how well a 20' Vertical Antenna plays on 80M compared to a 50' install (up on a tower). That's encouraging for those of us who don't have a tower, right? Sure, there is a difference, but how much really?
2. On 10-40M we see the ground-mounted Vertical competes well vs. the 50' height install for gain and low angle. This lends itself to Real DX! Not too shabby for a 20' tall antenna, right?
3. If you are one that can go a little higher, testing out the 24' or 28'er will add a little punch and lower angle on the lowest bands. It's not much but you never know, it could make a difference here and there. Here's a graph comparing the various Greyline Antenna heights in a similar fashion.
Before you choose a location, here's a Pro-Tip: Seek out Noise Sources before planting your new Antenna. Plant as close as possible to the quietest location on your property, or farthest away from the noisiest location on your land. That makes sense, right? Your everyday activities will be of a higher quality experience, trust me on this. If you can't hear them...
First, this applies to everyone. When considering ANY location to plant your Greyline Vertical Antenna, consider using a battery-powered AM radio, or similar, and walk around your QTH listening for any noise sources. If you have neighbors, it's highly likely some neighbors (or maybe you too) have QRN-producing products in or around the home, which should be discovered and hopefully addressed to resolution. In some cases, it's reasonable to assume that you may not be able to resolve some noise sources. In this case, you'll be glad you are aware of this information and then seek to find a quieter location to plant your Flagpole Antenna.
Common Theme: As with many summer locations, there is simply less noise when fewer homes or noise-producing elements are nearby. Typically a lake dock or house has water on one entire side of the take-off area expected for your antenna. This is a good thing. To a lesser extent but still applicable, a home on the end of a cul-de-sac or with no neighbors on the side may offer less noise for your antenna.
Many customers are installing their HF vertical antennas on boat docks at their lake homes across the country. Remember, radials are not needed with the Greyline vertical dipole (HOA Flagpole Antenna & HF Vertical Antennas) nor does it require guy wires to work properly. Do you recall "grounding" your dipole in a tree? Nope.
That said if you would like to experiment with improving your take-off from the ground, as lakes are typically not salt-water, and likely these radials will be elevated on or under the dock, you could try 4-16 elevated radials, ~6 inches above the lake should do it. Or try them on the ground below the antenna using 50-70 radials to find your sweet spot. Remember, when using radials you'll want to get this ground system correct otherwise it is likely a fool's errand, albeit fun to be outside tinkering with antennas, granted. Please do not connect these electrically to the Antenna system, for testing purposes as this system floats. The radials will work passively. Connect them later if you are certain it's matching properly with your antenna and ground system.
On the other hand, why fuss with radials? This antenna was designed as a vertical dipole or VDA, and this type of HF antenna does not require them. It will work fantastic as is, out of the box, and fastened (or roped off) to your dock. Temporary or permanent dock installations are common with Greyline Performance antennas. Just ask the many seasonal homeowners that travel north and south with the birds.
Lake houses, in our experience, seem to have common themes. One is, a wide-open space to work with, which is advantageous for overall efficiency in surrounding terrain take-off and likely fewer people around offering fewer adjacent noise sources (quieter QTH). This naturally lends itself to the likelihood that a healthy signal-to-noise ratio offers a super quiet noise floor on the radio, and this is always helpful. Every dB counts on transmit and receive too.
Do you want to try radials, but not on a dock? Okay, consider elevating 4-16 radials 3 to 6 inches above the ground. Consider 65-130 radials on the ground if you cannot elevate the radials. There is a science to getting the correct number and its relationship with this ground. You really do need 60+ to make a real difference. Or simply leave the radial topic aside as you do not need them with the vertical dipole antenna.
Ocean Front, Bulkheads, and Salt Water Docks:
You just may be the luckiest of the bunch when it comes to vertical dipole antenna install locations. The only place that can beat you is on a sailboat with 360-degree wide-open spaces or arguably a mountain top, the real mountain tops with those sharp long sloping angles. Alas, work with what we have, right?
OK, so we work to our strengths, whatever that may be. So, you have the wide-open spaces, typically, and your ground screen as many call it, is simply perfection. Miles and miles of perfection. A perfect reflection for your antenna's take-off angles and its receive performance too. Experience tells us that waterfront verticals compete with the big Yagi antennas on tall towers inland from you. This may not be common knowledge, but these high tower beam antennas may not hear what you are working on the bands, any band at certain times of the day. It can be that good. Consider installing your antenna as close to the water as you can, likely within 20-30' for best results. Guys several miles away from the seashore will also still enjoy this saltwater boost. Test it out, and remember, have fun!
We wish you only the most exciting adventures that we know are possible on the bands.
Memory Lane: KL2A recalls hearing N2NL/4 working him while in Kuwait City operating as KL2A/9K2 on 80M. N2NL was using a simple vertical antenna on his dock in the Florida Keys and no one could touch his signal the week Jon was on the air there. For several hours each morning, Jon KL2A was on the air from Kuwait City preparing for the CQWW CW contest, using an 80M Yagi pointed at the USA. Dave's vertical over that salt water was a memorable and steady signal not matched by any of the other big guns in the region, and no one was nearly as loud as he was that week.
Point of advantage: Low Loss ground system over salt water using a Vertical Antenna.
Again, you do not need radials with the Greyline Performance DX Flagpole Antennas on salt water or anywhere else for that matter. They are designed to work like 1/2 wave vertical dipoles. With a properly installed ground screen or radial field, tuned perfectly between your antenna and ground, it's not assured you will ever notice much of a difference.
Does anyone care to comment? What is your experience? Send us an email to share or discuss...
Where will you mount your HF Vertical Antenna or Flagpole Antenna? Leave us a comment below.
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