Saturday, September 17, 2011

Simple antennas for Hawaii Amateur Radio Operators, part 12


Over the course of the past few days, I finally added another skyhook to my modest antenna farm.  It took a few days to secure a few sections of 2" pvc pipe and to  assemble the wire, coax, and twin lead for the project.  The antenna consists of 32' of pvc pipe, 32' of 14-gauge housewire, 32' of 14-gauge wire serving as an elevated counterpoise, and 40' of 450-ohm twin lead attached to a 4:1 balun.  Approximately 15' of RG-6 coax runs from the balun to the Drake MN-4 ATU. 


No.  But it does work and can be used from 40-meters to 10-meters.  The design goes back to the 1920's and has been refined over the past years by many noted amateurs.  Other than buying a few pieces of pvc pipe, my expenses were zero.  Fortunately, I have a well-stocked "junque" box and was able to find nearly everything I needed on site.  I'm enjoying this simple antenna, given the space restrictions of my back yard.  Like my inverted "vee", this antenna can be swiveled down to ground level when it is not in use.  The visual impact of both antennas is minimal.  Since I do most of my operating after sunset, the antenna farm is largely invisible to the neighbors.


If verticals and dipoles aren't part of your antenna plans, you may want to experiment with loops of various sizes.  For those facing CC & R and HOA restrictions, a small magnetic loop may get you on the air.   MFJ sells a magnetic loop and all of the associated hardware necessary to keep you active from an unfriendly environment.  Although it appears a bit expensive, many amateur radio operators seem to like this product.

I was able to place a full-wave 40-meter loop (141') under my house for a backup antenna.  My qth is supported by pillars and concrete pads approximately 5' above ground level, so there is some clearance for the antenna.  This loop provides good regional service and works the Hawaiian Island chain with ease.  The loop is, for all practical purposes, a NVIS antenna with coverage stretching out to about 300 miles.  I get no RFI in the qth, since power levels are usually 10 watts or less.


If you live in an area where antennas are considered little more than an "eyesore" (thanks to CC &R and HOA restrictions), you may have to be a bit creative in getting your amateur station on the air.  An internet search for stealth or hidden antennas will reveal a wealth of information that can help you rejoin the ham radio community.  I have a well-worn edition of an ARRL publication on stealth antennas which has given me several good ideas.   Don't be afraid to experiment with low power, various digital modes, or unusual antennas.  The idea is to get on the air and enjoy the hobby with the resources available.  The local hardware store can supply you with most of the antenna items you need.  Even the local cable company may be willing to part with unused lengths of coax.  Fitted with suitable connectors, RG-6 can serve as a replacement for RG-58 and RG-8x.  A decent ATU can match this nominal 75-ohm cable to your rig. 

That's it for's time to close the news room and head for the qth.  I hope to squeeze in a few hours at the J-38 key on the lower portion of 40-meters before I roll back the sheets for a good night's rest. 

Have a good weekend.  Do your  best to get on the air...use it or lose it.  Aloha es 73 de KH6JRM.