- December 26, 2016 at 10:19 am #7809
You may recall that in my early Ham radio days, I mentioned I have connected and used the downspout in apartments I have lived in. WB3GCK has used this antenna very effectively:
The WB3GCK Downspout Antenna Revisited
The downspout has a vertical run of about 16 feet, connecting the horizontal rain gutter which is about 16 feet long across the front of the house. Including the feed wire into the shack, the total length is in the neighborhood of 42 feet; over a quarter wavelength for 40 meters and almost a half-wave for 30 meters.
I use my downspout like a random wire antenna, using a commercial autotuner (or internal tuner, in the case of my KX3). I feed the antenna through a homebrew 1:1 unun. A length of #22 stranded hookup wire is used to connect the output of the unun to the downspout outside.
To connect the wire to the downspout, I first sanded the downspout and connected the wire using three sheet metal screws. I used multiple screws to help ensure a low resistance connection. Goop is available at most hardware stores.
With the downspout behaving essentially like an end-fed wire, it really helps to work this type of antenna against a good ground. Fortunately, my basement operating position is only a few feet away from where the water supply pipe enters the house. I used a piece of 1/2-inch copper pipe as a ground bus between my operating position and the incoming water pipe. A tinned copper braid strap and a couple of ordinary automotive hose clamps were used to connect the bus to the water pipe. A short braid strap connects the ground stud on the unun to the copper ground bus.
For good measure, I attached counterpoise wires to the ground stud of the unun; one each for 40, 30, 20, and 15 meters. The counterpoise wires are made from garden variety stranded hookup wire cut to a quarter-wavelength. Operation on the 80 meter band has been successful using just the ground bus.
How well does it work? During the first few months of operation, I worked 49 states; all with 5 watts or less. I’ve also worked a bunch of DX stations (though I’m more of a casual rag chewer than a DX-chaser). The length of the “antenna” is somewhat short for 80 meters, but performance on that band has been a big surprise. Signal reports on 30 and 40 meters, my primary bands, have been consistently good I attribute this to the proliferation of electronic gadgets both in my house as well as my neighbors’ houses.
Make sure your gutter and downspout are isolated from ground. Watch your power. I wouldn’t recommend running a kilowatt into your rainspout. Ham radio is fun, but not worth burning down your house. There just might be a free multi-band antenna hanging out there!
72, Craig WB3GCK
see full article here: http://wb3gck.craiglabarge.com/the-wb3gck-downspout-antenna-revisited/
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