I posed this riddle to Joe, a classmate of mine: “Last night I built a full wave 40 meter antenna. It cost me about $2 to build, has a 1:1 SWR, pulls in signal like nothing else I’ve tried and is virtually invisible.”

Being a new ham he didn’t guess, but some of the more experienced hams knew. I had lit up my rain gutter system.

I got the crazy idea yesterday that three sections of the perimeter of my house actually added up to just under 40 meters in length, so I went out and measured and found that sure enough, it was. An hour later I had electrically joined my gutters into a ~41 meter long (including the downspouts) U shaped “random wire” antenna.

I found that others around the net had done similar things and here are a few pointers I gathered on this. Of course, if you try this at home your installation is your own responsibility/liability so do your own homework first!

1. Make sure all metal to metal connections are sound. Gutters are often missing screws and any gaps will allow arcing of the transmission and thus broadband interference. This includes gaps where two sections are joined on long runs, I just drove some small screws through every joint.
2. Use an antenna tuner with a very good ground.
3. Don’t use it to transmit when it’s raining. The water will disrupt the signal and additionally if you transmit while it is wet you may have some serious electrical hazards.
4. Did I mention a good ground? Both the radio and antenna tuner should be connected to the ground by the shortest length of ground strap possible. If you can’t do a good ground, do not try this antenna.
5. Take measures to ensure nobody can touch the metal parts of the gutters when you are transmitting or they may be burned. One easy way to do this is to replace the metal downspouts with vinyl ones.

Another idea I had along this line since my house has gutters only on the longest sides of the rectangle is to use one gutter as a driven element and the other as a reflector or director. A whole-house 80 meter yagi might be possible though I would likely not get a strong directionality since the height of the gutters are only 1/8 wave high on that band. The gutter setup already seems to have a certain amount of north-south directionality though due to the U shape as it is, I worked and heard mainly stations south (TX) and north (Canada) last night. If I try the yagi idea I will talk about it here so stay tuned.

Update Jan 2008- I have ditched the gutter setup and opted for a long wire sloper instead after modeling the gutter on 4nec2. The rain gutter was so-so for local contacts but it was a serious cloud burner- all the signal went straight up instead of out and there was at least 13dbi of attenuation at any reasonable elevation level. The sloper is quite a bit better at least on computer models, will post about it when I have tuned it up.

Update Mar 2008- The sloper as I designed it was nearly useless in practice, it really needs a yagi or some sort of “hat” to work when top fed evidently. The rain gutters were actually better. I’ve since reallocated the rain gutters to perform as part of my radial system for my MFJ-1793 20/40/80 vertical however which beats all previous attempts as expected.