N2NL's 40M VERTICAL

click the photo's for full size view

    When I was transferred to my present location, my priorities were finding a home my wife liked, had good schools for my son, and fit within the budget of my USCG housing allowance.  We found a great place in Palm Beach Gardens which was quite large, with a large private screened-in patio, and in-ground pool.  Unfortunately, it is VERY antenna un-friendly, being located in a small private community with very strict regulations.  When I moved, I didn't consider this a big deal since I mostly guest operate in contests from larger stations than I'd ever be able to have at this time.  After a while, however, I got the bug to put up SOME sort of antenna,  something stealth that would allow me to get back on the air.

My home with the antenna folded over

    I don't normally DX anymore, since the packet pileups have gotten too crazy and the expenses for getting that stupid piece of paper to confirm the contact (QSL card) have really turned me off.  When I do play around between contests, I most enjoy the low bands where the challenge of copying weak signals through QRM make it a challenge.  My two favorite bands are 80 and 160m, but I knew it would be near impossible to install an antenna for those bands that would perform to my demands and keep it hidden from view.  I wanted an antenna that would be competitive with others.  That eliminated 10-20m from my list.  Yeah, I could put up a small vertical pretty easily but I'd be beaten by everyone with a 3el tribander at 30ft. 

    That left 40m.  I did some measuring....my patio measures 20ft by 40ft.  A quarter wave vertical for 40m is about 34ft long.  I decided to built a 40m vertical out of aluminum tubing with a swing mount.  During the day it remains folded over, hidden along the edge of the gutter behind the screening.  At night, I can swing it up and get on the air.

    I wont go into specifics of construction, but you can catch the drift of how I did it from the photos.  I mounted a 1/4" plate of aluminum to the screen porch framing.  I got a piece of starboard (a strong type of plastic easy to work with, cut, drill, often used on boats) and mounted the vertical to that.  I went to a motor rewinding shop and purchased 1000ft of #18 enameled copper wire for radials.  It turned out that the enameled coating was a light brown color which blended in perfectly with the roof shingles.  I purchased the aluminum from Texas Towers, INC. 

    Once completed, I had a full size 40m vertical, painted brown to match the gutter paint and to make it less visible.  Presently I have 30 radials, all 30ft long, which run up on the roof.  In addition, the framing of the screen porch is tied into the ground system.  Basically, it is an elevated vertical, with the base at 10ft.  It is directly fed with RG-8X.  I placed a coax choke at the base more out of habit than necessity, but incase I decided to use the vertical on other bands through a tuner. 

Here is the antenna folded up, leaning slightly in the wind

     How does it work?  WOW!  I was immediately impressed.  My first QSO was with YB1A in Indonesia, long path.  This antenna has turned out to be really kick ass on 40m.  I easily work long path DX, walking right through pileups with ease.  YB. 9V, HS, and XU are just some of the LP DX I've worked.  I very rarely get beat to 4S, VU, EX, 4K, and other deep Asian countries.  At home I'm using my IC-706, turning on my LA-1000 amplifier (500W) only when the pileup is large.  I hear extremely well, due to the low angle characteristics of the vertical.  On air testing with K1PT and his 2el 40m yagi @70ft confirms my vertical really performs well.

    I can also use this antenna on 15m without a tuner.  It is completely invisible when folded down, and at night you can barely see the vertical when there is a full moon.  I have no TVI when low power on 40, however I do have very minor interference when running HP, probably due to fundamental overload of my TV due to its proximity to the antenna.  I highly doubt any of my neighbors suffer any TVI whatsoever, although I don't advertise the fact I have an antenna.  In the future, I plan to increase the number of radials to 60.

  The base of the vertical.  I overbuilt it mostly to make sure it wouldn't come crashing down at night.

   Another view of the base.  Two large bolts attach the entire assembly to the porch framing which in turn is bolted to the house.  When I move, I remove the antenna and 2 bolts, fill the holes with Bondo, paint the frame, and reinstall the screen.

  From the roof you can see the radials I strung across the roof.  I placed some bricks at the feed point to keep the radials down against the roof.  The far ends of the radials are folded under shingles to keep them in place.

Another view from the roof.

  Even from the patio the antenna is difficult to see when folded over.

  This is that the base looks when the antenna is raised.  I insert a bolt to act like a pin to keep it extended vertically.