The Cloud Warmer (for 80 meters)


Figure 1:  The cloud warmer for eighty meters.  Click to enlarge.

So, on eighty meters my signals were always in the dust. In the fall season, with thunderstorms hundreds of miles away, I had an S6 static noise level, with crashes above that.  It was enough to drive me back to the forty meter CW band.  The problem was twofold.  First, I had a very “loaded” 80 meter attic dipole, and secondly, it was a dipole.  Hence it was poor to begin with (being both loaded and in the attic), and a great static noise scooper (like all dipoles are).

The solution?  A (mostly) horizontal loop.  Why horizontal?  Because it’s tough to find the vertical space in any attic for 285 feet of wire!

Now, even horizontally, I was going to come up short.  50×2 + 35×2 = 170 feet, which is well short of the requirement.  So, about 70 feet of the loop is an up-and-down pattern, affixed to those six inch plastic stand-off insulators, supported from the gables.  The other eighty five feet?  It’s in the nooks and crannies, believe it or not. It adds up. I used Gimp on FreeBSD in etch-a-sketch mode to draw the antenna, and it’s definitely not drawn to scale (for those observant types who did the math).

So, how does a mostly (seventy five percent) horizontal, twenty five percent vertical “horizontal” loop perform?  Let me tell you.

First, I decided to run “almost QRP” mode on the antenna.  Lord knows what the voltage and current distribution is on this monster, so I ain’t taking any chances.  Experimenting with ten watts of “near QRP” power, put thru a coaxial Q matching section, resulted in the highest dB numbers I’ve ever recorded on  Many of the stations were receiving me at 35+ dB, and a couple over 40 dB!  I’d never seen such a thing, even on the forty meter CW band, where I have a full size (albeit very bent) dipole.

The noise?  It dropped from S6 to between zero and S1!  Suddenly, I had an eighty meter DX machine.  I’d never worked *any* DX on eighty meters.  The six’th contact I made with the loop was EA1DR, in Spain.  I was converted at that point.  Loops are in, dipoles in the bin.

Now, in the lore, a horizontal loop is a cloud warmer.  What the provocateurs of the lore mean to say, is that the radiation is all blasted straight up, like a HAARP competitor on steroids.  But, I’ve read competing theories on this, saying that some fine medium angle radiation results from the horizontal loop configuration.  And – my loop does have some vertical component, although I doubt it means anything.  It seems I have real nice lobes up into New England ( 700-1000 miles).   The european skip I’m hearing may be partially due to a convenient QTH on the east coast, and a good bounce on the salt water.  But, this thing not only warms, it cooks, and not just the clouds.