Happy Stealth Antenna

[dkcorlfla]

I made a stealth flagpole HF antenna from a low cost flagpole kit from amazon and it is working great so I thought it would be good to share.

The kit I used was called: Wevalor 20FT Sectional and what's unique about this kit is it uses swage sections that fit together without using plastic sleeves so it is easy to make the whole thing have continuity. I simply used auto hose clamps at each section to make the electrical connection. The kit came with 5 sections but I ended up using just 4. It is mounted on top of a SCH 40 steel pipe with PVC used to isolate the top from the steel pipe base. 3 radials each for 40, ,30, 20, 10 meters for a total of 12 radials. Each group of 3 was cut to 1/4 wave for each of the bands and slotted just under the surface of the front yard.

Amazed at how well it has been receiving and from what I see by using FT8 and pskreporter it gets out well on 30, 20, 15 and 10. I have to use a loading coil for 40 but have not used it enough yet to get a feel for how it does on 40.

Can provide more construction detail if anyone is interested.

Ended up being a fun project and now I have a nice looking stealth HF antenna in the front yard away from the power poll/line RFI problem I have in the back yard.

 

[QPLou5645187]

This is an interesting concept! I would like some more details if you'll consider sharing.

 

[dkcorlfla]

This is an interesting concept! I would like some more details if you'll consider sharing.

Sure, here are 5 pictures that help show how it went together:

The lower pot covers the balun. The picture of the baun also shows the radials if you look close. The base detail shows the bolt drilled through the PVC coupler that prevents the flagpole from dropping to the bottom of the base. It also shows the continuity screw that runs into the bottom of the flagpole and the simple clip used to attached. I might have to re-visit if it corrodes but for now it's working great and lets me patch in the loading coil for 40 meter without moving the pots. The pipe picture shows the SCH 40 1/12 PVC that gets installed inside the flagpole, the 2 inch SCH 40 steel pipe, the 2 inch PVC coupler that press fits on top of the steel pipe. The short section lower left of the picture shows the 2 inch SCH 40 PVC pipe that on the flagpole pictures is painted grey to make it less visible and to protect the PVC from the sun somewhat.

One thing to note is the flagpole does not extend down into the steel base it is held up about 1/2 inch by the bolt. There are two PVC SCH 40 pipes one inside the flagpole and one outside. It does flex a bit when it's windy but so far it has not been a problem.

Let me know it any questions.

BTW - I used my old MFJ 969 tuner and it works ok but a outdoor auto tuner at the base would be better.

 

[merlin]

The best HF stealth/HOA friendly antenna I have seen is the Broad Band Terminated Dipole.

 

[popnokick]

... and here's a slight variation and some more info on the BBTD -
Roof Mount for BBTD Cable?

 

[QPLou5645187]

Sure, here are 5 pictures that help show how it went together:

The lower pot covers the balun. The picture of the baun also shows the radials if you look close. The base detail shows the bolt drilled through the PVC coupler that prevents the flagpole from dropping to the bottom of the base. It also shows the continuity screw that runs into the bottom of the flagpole and the simple clip used to attached. I might have to re-visit if it corrodes but for now it's working great and lets me patch in the loading coil for 40 meter without moving the pots. The pipe picture shows the SCH 40 1/12 PVC that gets installed inside the flagpole, the 2 inch SCH 40 steel pipe, the 2 inch PVC coupler that press fits on top of the steel pipe. The short section lower left of the picture shows the 2 inch SCH 40 PVC pipe that on the flagpole pictures is painted grey to make it less visible and to protect the PVC from the sun somewhat.

One thing to note is the flagpole does not extend down into the steel base it is held up about 1/2 inch by the bolt. There are two PVC SCH 40 pipes one inside the flagpole and one outside. It does flex a bit when it's windy but so far it has not been a problem.

Let me know it any questions.

BTW - I used my old MFJ 969 tuner and it works ok but a outdoor auto tuner at the base would be better.

Thank You! This is excellent!

 

[lebrunmn]

Nicely done! Many thanks for sharing the details of how you constructed it.

May your HOA stew in its own juices!

 

[merlin]

... and here's a slight variation and some more info on the BBTD -
Roof Mount for BBTD Cable?

Yea, and they have a couple DB gain, even suspended vertically between 2 poles.

 

[merlin]

Sure, here are 5 pictures that help show how it went together:

The lower pot covers the balun. The picture of the baun also shows the radials if you look close. The base detail shows the bolt drilled through the PVC coupler that prevents the flagpole from dropping to the bottom of the base. It also shows the continuity screw that runs into the bottom of the flagpole and the simple clip used to attached. I might have to re-visit if it corrodes but for now it's working great and lets me patch in the loading coil for 40 meter without moving the pots. The pipe picture shows the SCH 40 1/12 PVC that gets installed inside the flagpole, the 2 inch SCH 40 steel pipe, the 2 inch PVC coupler that press fits on top of the steel pipe. The short section lower left of the picture shows the 2 inch SCH 40 PVC pipe that on the flagpole pictures is painted grey to make it less visible and to protect the PVC from the sun somewhat.

One thing to note is the flagpole does not extend down into the steel base it is held up about 1/2 inch by the bolt. There are two PVC SCH 40 pipes one inside the flagpole and one outside. It does flex a bit when it's windy but so far it has not been a problem.

Let me know it any questions.

BTW - I used my old MFJ 969 tuner and it works ok but a outdoor auto tuner at the base would be better.

It looks clean.

 

[dkcorlfla]

The best HF stealth/HOA friendly antenna I have seen is the Broad Band Terminated Dipole.

That would certainly be an option for some but one of the reasons I went with a ground plane vertical is I wanted the low radiation pattern that the vertical offers. Seems to me the antenna above because it is mounted so low would be great for NVIS but not so good for DX. Also, my house has aluminum soffit all the way around the outside that I would think would cause issues. I also have a lot of RFI that seems to be horizontal polarized. The flagpole vertical picks up much less RFI then the horizontal dipoles I have tried in the past. I know that is not how it is suppose to be, verticals are suppose to pick up more man made RFI but that is not what I found at my location. Installation is also something to think about. The vertical did not require any ladder work. The dipole above looks like it would take a lot ladder work or a trip up on the roof with some work close to the edge.

Just some things to think about.

 

[kenn_moses]

My most stealthy antenna is an Alpha Delta DXEE 10-40 fan dipole strung in the attic of my garage. A Kenwood TS-450 internal tuner is able to match the antenna well enough to make any POTA or SOTA contact I call. My neighborhood HOA prohibits any antenna on the property