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[Articles Home]  [Add Article]  

The 'Lazy 7'

from Tim Cotton, N4UM on January 4, 2012
View comments about this article!

The “Lazy 7" -- A Nine-Band Stealthy “Fly By Night” Antenna
By Tim Cotton, N4UM

The “Lazy 7” evolved over the course of several years while living in an HOA where antennas are prohibited by local HOA covenants but “flagpoles” are permitted under Florida state law. It started out as a clandestine antenna for 40 thru 10 meters. The flagpole is 23 feet tall and is used alone for operation on 40 thru 10 meters. A top loading wire is used on 80 and an inductor is inserted in the top loading wire for 160 meter operation. I'm able to get away with using my flagpole during the day but have to wait for darkness to use the top loading wires. Since 80 and 160 are primarily useful at night, this is really not much of a handicap. This diagram illustrates the Lazy 7 as set up for 160 meter operation.

First, lets build a “flagpole.” I used six foot sections of .058 inch wall aluminum tubing to construct the flagpole. I started with a piece of 2” O.D. tubing and nested a second snug fitting smaller diameter piece of tubing inside of it to double the wall thickness to .116 inches. I proceeded in this fashion – overlapping each double walled six foot section by about 6 inches until I reached a height of 23 feet. Generous amounts of “Penetrox” were used between the sections to assure good conductivity and permit dis-assembly if that became necessary in the future. Sections were held together using stainless steel sheet metal screws. A PVC end cap was fitted over the top of the flagpole. Then, a pulley was attached at the top of the pole and a small halyard cleat was mounted about 3 feet above the lower end of the pole. A ¼ inch nylon halyard with two loops for flag clips was threaded through the pulley and through a hole in the cleat. The completed flagpole is light enough for one old guy to stand it up and drop it over the mounting pipe. Putting the flagpole up or down takes less than 15 seconds.

The next step (the hard part) is constructing the flagpole mount. Begin by digging a hole 36” deep by about 18” in diameter in a good spot. A good spot is one where you have room to install a decent radial field and where you will be able to run your coax as conveniently as possible.

Next, encapsulate a 5 foot piece of 1” galvanized steel pipe inside a snug fitting piece of PVC pipe and use PVC cement to glue PVC end caps onto each end of the pipe. You want the galvanized pipe insulated from everything. Make sure the encapsulated pipe will fit inside the bottom of your flagpole!

Center the encapsulated pipe in the hole and brace it in a vertical position allowing 36” of the pipe to go down into the hole and leaving 24” out of the hole.

Pour concrete into the hole, making sure the encapsulated mounting pipe remains vertical. Pour the concrete so that its surface is 1 or two inches below ground level. Let the concrete set up for a day or two.

Fabricate a ¼ inch thick aluminum radial plate with a hole in the center just big enough for the encapsulated PVC pipe to slip thru. Slip this over the mounting pipe on the surface of the concrete.

Attach your radials to the radial plate. I used 50 radials made from solid #14 THNN insulated wire from Lowes/Home Depot - each about 20 feet long. I staked them down to the surface of the grass using home made lawn staples constructed from #12 galvanized steel wire. Water and fertilize the grass heavily for a month or two after this. The radials will eventually disappear into the grass.

Construct a base insulator plate by cutting a hole in a piece of Lexan cutting board (or other good insulating material) that's about ½ to ¾ inches thick. Make the hole just big enough to snugly slip over the encapsulated PVC pipe but small enough so that the base of the flagpole can't slip through it and come in contact with the radial plate. Place the insulator plate on top of the radial plate. See base assembly detail below.

Obtain a rubber “tree ring” 36” in diameter from Lowes or Home depot. Place this around the mounting pipe and on top of the insulator plate. Cut a hole in the center of the tree ring so that it clears the base of the flagpole. I used landscape bricks from Lowes/Home Depot sitting on the outer edge of the tree ring for a decorative effect. The purpose of the tree ring is to conceal the radials in proximity to the flagpole.

Buy a big plastic flower pot from Lowes or Home Depot. Drill a hole exactly in the center of the bottom that is large enough for the base of your “flagpole” to easily slip through.

Insert the flagpole base through the hole in the upside down flower pot and then slip the flagpole down over the encapsulated supporting pipe. Make sure the flagpole is NOT in contact with the radial plate. Attach the center conductor of your coax to the flagpole and the braid to the radial plate. Your flagpole is now ready for operation on 40 thru 10 when used in conjunction with a remote autotuner placed as close to the feedpoint as possible. The completed flagpole is shown in the photo below.

I initially buried the coax going out to my flagpole but had to replace it after heavy rains flooded out the feedpoint and eventually corroded the coax. Instead of burying new coax I first buried 1” PVC electrical conduit from my house out to the flagpole (keeping the run as straight as possible) and ran the new coax thru the conduit. Replacing any coax in the future will be a simple 5 or 10 minute task that does not involve digging up my lawn! I left a “pull string” inside the conduit for future use.

My remote autotuner (MFJ-998) tunes the flagpole on 40 thru 10 meters when feeding it through 13 feet of coax. The autotuner sits in a Rubbermaid cabinet on my back porch. I initially installed a loading coil concentrically with the base of the flagpole having manual taps for 60, 80 and 160 meters. The power must be kept low on 160 meters because of the high voltages that are present on the loading coil. The coil is not very efficient and is only used when no top loading wire is connected. I eventually removed the coil.

A top loading wire greatly improves the flagpole's efficiency on the lower bands. I modified my original design by removing the concentric base loading coil and using a top loading scheme on 80 and 160. I permanently attached a 20 foot piece of #14 THNN stranded wire to the top of the flagpole. This wire may be pulled out from the pole at night and used as part of a 60 meter antenna. The 20 ft. wire is normally spiraled snugly round the pole 3 or 4 times so that it doesn't blow around in the wind or affect the radiation properties of the flagpole on 40 thru 10. At night when I want to operate on 80 meters I unwind the 20 foot piece of wire and attach a second 27 foot wire to it. The resulting 47 foot wire slopes downward to a height of about 7 feet at the far end. I use a similar setup for 160 but insert a loading coil of approximately 100 uH in between the two loading wires. The coil is wound with #14 THNN stranded wire from Lowes or Home Depot. I used a plastic jar about 5 ¼ inches in diameter as a coil form. The coil consists of 27 turns wound over a length of 3 inches. I have found a “hot glue” gun to be indispensable in coil construction. The top loading wires and coil are designed for quick and easy installation and removal in the dark.

I call the antenna a “Lazy 7” because that's what it looks like from the side with the top loading wire in place. It's really an “Inverted L” with a relatively low support for the far end of the loading wire. The flagpole alone performs quite well on 40, 30 and 20 meters and is satisfactory on 17 thru 10 meters. Although I spend most of my time rag chewing on the digital modes, 214 countries have been worked on the flagpole in a little over two years of casual DXing. I have been able to work some DX with it on 80 meters even though the vertical radiating section and ground radials are quite short for that band. It's not much of a DX antenna on 160 but it at least enables me to get on that band and make contacts out to about 1500 miles. It works much better on 160 than the quarter wave I had stapled up under the eaves of my house about ten feet above ground. It also works much better than my 80 meter attic dipole, particularly on DX. The antenna has handled 800 watts on all bands with no ill effects.

There's really nothing critical about the dimensions of the antenna. I chose a 23 foot flagpole because that was close to resonance on 30 meters. It also was short enough not to provide a lot of high angle radiation on the higher frequencies but was long enough to be fairly efficient on 40 meters. The 20 foot top loading wire is permanently attached to the top of the pole so that it can spiral around the pole using a small bungee cord to keep tension on the wire when it was not deployed. The additional 27 foot loading wire was as long as my lot could accommodate. W7EL's EzNec program modeled the antenna and helped me to estimate the value of the loading inductor I would need on 160 meters. My autotuner is able to provide decent matches to the antenna thru the 13 feet of coax with losses that appear to be tolerable.

Should you decide to build your own variation of the Lazy 7, I highly recommend that you download the free demo version of W7EL's EzNec program and spend a bit of time familiarizing yourself with it before modeling your own particular setup. I've found it to be very helpful in modeling my ideas before embarking on a new antenna project.

Living in an antenna-restricted neighborhood does not have to be a death sentence for your ham radio activities unless you choose to make it that!

Member Comments:
This article has expired. No more comments may be added.
 
The 'Lazy 7'  
by KY6R on January 4, 2012 Mail this to a friend!
Excellent article - thanks!
 
The 'Lazy 7'  
by N2RRA on January 4, 2012 Mail this to a friend!
Nothing new and seen this before ,but a great way to remind and implement on how to screw the fat headed HOA folks. Improvisation is the salvation in this case.

Good article! 73!
 
RE: The 'Lazy 7'  
by N4UM on January 4, 2012 Mail this to a friend!
My article was not really meant to be about "screwing the fatheaded HOA folks." If anything, it was about living with the choices one makes. Nobody ever forces someone to join an HOA. One chooses to do so and must learn to live with the consequences. If one chooses to live next door to a pig farm, they don't have a legitimate basis for complaining about the smell!
 
The 'Lazy 7'  
by KD4LLA on January 4, 2012 Mail this to a friend!
I grewup on a farm next door to pigs. I would rather live next to a pig barn than in a covenant controlled HOA. Feeder pigs never complain about the number of antennas, color of your house or whether there are too many cars in your driveway...

Mike
 
The 'Lazy 7'  
by K1HC on January 4, 2012 Mail this to a friend!
Nice article! Thanks for posting it. It is always nice to see how someone works out getting on the air despite restrictions. Congratulations!
 
RE: The 'Lazy 7'  
by W3FHT on January 4, 2012 Mail this to a friend!
Besides, you could always eat your "neighbors"!
 
RE: The 'Lazy 7'  
by N4JTE on January 4, 2012 Mail this to a friend!
Tim, nicely done, having lived on and off in Ft. Lauderdale for 30 years I am amazed that you can get on all the bands of your choice in the typicaly small and highly observed back yard.
That sucker is certainly invisible !
You probaly already know that the efficency is just a little better than a hamstick on a mag mount below 20 meters, but you have presented many good stealth tips
and and if they let me back into the land of approved color garbage bags it will come in handy.
Tnx,
Bob
 
RE: The 'Lazy 7'  
by W5GNB on January 4, 2012 Mail this to a friend!
A very neat idea for hidden antennas but what is sad is that you have to sneak around within your own living area and hide your activities from your neighbors.

I am sure GLAD I live out in the country where I can step out on my front porch and light off my shotgun or take a leak if I so desire.... Not to mention putting up ANY Antennas I desire....

You boys can have that Big City life !!!!

W5GNB
 
RE: The 'Lazy 7'  
by K8AXW on January 4, 2012 Mail this to a friend!
I prefer to look at it as a way to screw the HOA people as well!

Good job! Very interesting read.
 
The 'Lazy 7'  
by AB9TA on January 4, 2012 Mail this to a friend!
Tim,
Nice article, very resourceful.
Having worked you on 80 and 160 from noisy Chicagoland, I'd say this antenna radiates a lot better than people might think.

73!
Bill AB9TA
 
RE: The 'Lazy 7'  
by G3LBS on January 5, 2012 Mail this to a friend!
W3FHT recommends eating neighbors, only if they are pigs. I can see no point in restricting this to pigs.
I am vegetarian, but not averse to cannibalism. It keeps the population down in a more humane way than war. If any of you have a tender HOA please let me know. W2/G3LBS.
 
The 'Lazy 7'  
by WX7G on January 5, 2012 Mail this to a friend!
Tim, you have designed and excellent antenna and have written and excellent article!

 
The 'Lazy 7'  
by VE3TMT on January 5, 2012 Mail this to a friend!
I understand the choice to live under the HOA Nazi's if you choose, but as a radio operator, why would you? If you are a muscle car freak, would you buy a Honda Accord? After having dealt with apartment cops for 20 years, hiding my antennas, putting antennas out a night and all that, I was in heaven when I bought my house. Being in an older neighborhood with no tower restrictions, I could pretty much put up what I wanted. If any of my neighbors had an issue, too bad, it's my house, my property and unless they are going to make the mortgage payments, mind their own business.

After 6 years here, I get more curious questions about the hobby then complaints.

73,
 
The 'Lazy 7'  
by AB6ND on January 6, 2012 Mail this to a friend!
Congratulations on a well written article.
I applaud the mature way you handle the snide comments.
73
Roy
 
RE: The 'Lazy 7'  
by N9BH on January 6, 2012 Mail this to a friend!
I applaud the mature way you handle the snide comments.

I agree. There are many factors that effect choosing a home. Efficient antennas may be one of them, but certainly other reasons may outweigh that.

73
Bruce

 
The 'Lazy 7'  
by PA3GWO on January 6, 2012 Mail this to a friend!
We all could learn a lot from such a great article and Tim has shown again that there is always a antenna-solution.
Thanks for sharing your experience and please continue doing so.

Best 73 Tony PA3GWO
 
RE: The 'Lazy 7'  
by LA9XSA on January 10, 2012 Mail this to a friend!
Thank you for this inspirational article.
 
RE: The 'Lazy 7'  
by N5TGL on January 10, 2012 Mail this to a friend!
"I understand the choice to live under the HOA Nazi's if you choose, but as a radio operator, why would you?"

Because the world doesn't revolve around ham radio. Because maybe the house you want is in a HOA. Because maybe your XYL wants to live where there is an HOA and thinks that ham radio isn't that important -- a hobby vs. a house, guess who wins? Because you don't want to divorce your XYL so you can play radio. Because many areas without HOAs are in undesirable locations.

Most of these questions that are dismissed simply with a wave of a hand are far from being simple. It also doesn't prevent many people from spouting the myopic retort "well, just move!" Yeah, like they never thought of that.

Full disclosure: I don't live in a HOA, but fully understand why some people do.
 
RE: The 'Lazy 7'  
by K4JC on January 11, 2012 Mail this to a friend!
Nice article, Tim. You could modify this idea slightly and make a nice HF emergency or Field Day antenna. I like it!

No the world doesn't revolve around ham radio. But it has been such a big part of my life for so long I couldn't imagine being without it! That's why when I bought my current home, the very first thing I explained to the realtor was, "NO HOAs!!!" and explained amateur radio to her. The result was a place where I can put up whatever antennas I want and the neighbors don't care! (Did I mention my neighbors are ponies? The Mercedes and sauna will come later...) BTW I was a ham long before my wife came into the picture, so she knew she was getting a package deal! :-)
 
RE: The 'Lazy 7'  
by N5TGL on January 11, 2012 Mail this to a friend!
K4JC:

I agree completely, and your situation is very close to mine. When we moved, that was a stipulation I put on it. Took us 3 years of informal looking, but we finally found a place.

I am (and you are!) blessed with the ability to change our QTH and meet with our hobby's needs. Many folks don't have that luxury. All I was saying is that I feel that the people who say "move!" are being extremely crass, ignorant and uninformed about the opposite party's situation. It just makes me want to say "Gee thanks, Captain Obvious!"

With all that said, the antenna design is pretty darn neat, and a good solution for those who don't have much space.
 
The 'Lazy 7'  
by N4DDP on January 13, 2012 Mail this to a friend!
Great Article and well planned antenna.

I too face a similar situation in that I am in a CC&R neighborhood. I am not whining, I have so far tried a wire running up my palm tree with good results on 20-10. The only problem is my dog or kids running by and breaking the fine wire! I am looking hard at the flagpole idea as a more viable solution for HF.


Amazing how the HOA Comments seem to dominate, the ones that say "move" haven't tried to find an affordable home in this area which not only does not have restrictions, but also is in a decent school district and not a high crime area. Personally I wish there could be a more "sensible" solution than having to hide the antenna so carefully. I cannot imagine that a HF6V or such is really all that big a deal. However, the rules are what I signed up for when I bought the house. Sometime in the future I hope to build on a few acres in an area where no one will care. But until then I have to do what I have to do.
 
The 'Lazy 7'  
by AB6ND on January 14, 2012 Mail this to a friend!
Well said N4DDP. As hams are discovering world wide communication is possible without elaborate antenna arrays, many prefer the economic domestic bliss of living in s modern home close to work. They are the hams of the future, as the 'Big Guns' go to that ham shack in the sky and antenna farm land becomes more expensive.

The majority of the comments calling HOA Nazi etc. are from belligerent types who would not be pleasant neighbors even if their hobby was stamp collecting and not ham radio.

In addition using the term 'Radio Operator' to influence HOA doesn't impress them. No skill is needed to press a button on the side of a walkie talkie, thousands of people do it daily in the course of their job.

Unlike WW2 when hams were in demand by all services, very few of us have any electronic skills.

73
Roy




 
The 'Lazy 7'  
by W9CW on January 15, 2012 Mail this to a friend!
Nice article... not all hams live on a farm with acres and acres of real estate, or in non-restrictive subdivisions. HOA's are required by the developer, and sometimes by the city, in many areas, even before the land is platted for sub-division. Thus, I find this article appropriate for those who need some ingenuity, and some stealth, for a "antenna-challenged" location. I also wish those of you who always say something negative or carp about any and all postings similar to this would just keep it to yourself.
 
RE: The 'Lazy 7'  
by K5MO on January 26, 2012 Mail this to a friend!
Great article. If you WANT to get on the air, you can always find a way....and make a lot of contacts too!

73
John
 
RE: The 'Lazy 7'  
by N4UM on January 29, 2012 Mail this to a friend!
A final note...

The CQWW 160M contest proved to be a good opportunity to check out the Lazy 7's performance on 160. It's performance surprised me... 310 QSO's, 44 states, 6 Canadian provinces and 22 countries - including HK0NA on Malpelo Island. All this in about 14 hours of operating.
 
The 'Lazy 7'  
by KC9EHQ on February 8, 2012 Mail this to a friend!
Definitely a good article, and idea for an antenna. Depending on what kind of space you have, this would be a good antenna, HOA restrictions or not.

I was really getting excited about possibly building one until the "R-word" was mentioned...RADIALS. That is my downfall for putting a vertical up in my yard. At the center of my backyard, I have 35' on either side, and around 20' from the house to the neighbor's fence. Also, the deck does not help! The front yard is even worse because of the driveway and sidewalk. If I was to use a counterpoise kit, I would have to have the antenna about 7-8' off the ground to facilitate mowing.

One of these days I will figure out a vertical solution...

 
The 'Lazy 7'  
by W3TTT on February 12, 2012 Mail this to a friend!
Tim
Great article and it's good to see a fellow Cotton who is also a ham. We should set up a sked sometime.

I use a full 80 meter quaterwave vertical with raised radials. I didn't see in your article how many radials you use or how long they are. But with raised radials I can get away with just two or three on each band. Still has excellent performance, although I am not nearly as active as you are.

73
Joe Cotton
W3TTT
 
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