Stealth antenna? Can you spot the wire? Neither can we. The wires are almost invisible in this picture. The support post on the left side with the crossarms is about all you (or the neighbors) can see.

For more information, this antenna is written up in The ARRL Antenna Compendium Vol. 2, p 39, by Russell Prack, K5RP. Figure 2 is a drawing from that article that gives an idea of what the antenna looks like.

I was amazed at how well it works, which made me want to find out more about it. Part way into my research I concluded it needed a new name to be more descriptive and help to explain it. I believe a clearer name for it would be "Folded Skeleton Slot Antenna". Let's examine that name word-by-word beginning with the word, "Folded".

Fig. 13-2 is from Antennas, Second Edition, by John D.Kraus,W8JK, p 626.

A true slot antenna is fed along it's ends which is somewhat impractical at HF. The feed points would be 32 feet apart (for a 20m loop), making it very difficult logistically to connect a coax or twin lead feed line. Also, the feed point resistance is 550 ohms.

In one attempt at an improvement, Kraus moved the feedpoint close to one side which lowered the feedpoint resistance--but the connections are still 4 feet apart at 20m, still unmanagable logistically for the feed line.

Alas, someone tried a simply elegant solution, and that is to fold the whole antenna back almost onto itself, close to but not touching. When the antenna is folded we accomplish two things. First, the feed points are physically close to each other, solving the logistic problem for the feed line. And second, it cuts the feed point resistance by a factor of 4, to 135 ohms, making it easier to match with a balun. Voila! We need to examine what happens to the antenna currents when it's folded in the next section.

So that explains the word "Folded". Now a look at the second word in our new name, Skeleton.

A slot antenna like shown in Fig 13-2 would normally be used at microwave frequencies and be constructed from sheet metal. At HF we'd need a LOT of sheet metal. As you are probably aware, electrons at RF flow only on the surface, and in the case of a slot antenna, it only flows along the inside edges of the slot. The edges can be simulated electrically by wires. What a break. This means we don't really need all that sheet metal. We can build it from wires, instead. An antenna that is constructed from wires has been termed a "Skeleton".

And finally, the words, "Slot Antenna", have been mentioned repeatedly all during the discussion above, so it doesn't need expansion.