A common problem of the HF bands is skip over near stations. There are a couple of techniques that could help. NVIS and "snakes."

    The NVIS antenna is simple to make and works on nearby stations. It's not a DX antenna but for a county hunter in Michigan trying to get Indiana, Illinois, Ohio or Wisconsin, it could be a certificate saver.  Somewhat dependent on frequency,  probably best on 80 or 40, it would cover a few places a little further away than the above states.  It's a simple antenna, a dipole cut to the normal 1/2 wave length.  But!  we place it closer to the ground than normal and give it a reflector.

    Using 40 meters as an example: the dipole would be about 65 feet long, center fed with a 1:1 balun hung about 13 feet above ground on which a wire about 68 feet long would be placed directly below on the ground and parallel to the dipole. We've created a 40 meter yagi antenna pointed straight up! A driven element 1/2 wave long, placed 1/10 wave above a reflector 5% longer than the dipole.

    A last comment on this NVIS antenna, The S/N (Signal to Noise) ratio is much improved. Thus it will be quieter than most antennas.

    While the NVIS can be used to transmit, the "snake" would have to be carefully treated as a transmit antenna. "Snake!" I like that description. John Bordelon reports: " I once tried 100 feet of coax laying on the ground in the "snake antenna" arrangement. Darned if it didn't work pretty well, and was low noise.  Not efficient, but low noise, and the low efficiency was taken care of by kicking in the preamp on my Icom R75.  I could hear several low
frequency beacons in the Atlanta area and picked up WWVB at 60 KHz with no problem."

    What's a "snake" antenna? It's a long piece of coax thrown out on the ground that is shorted at the far end (sealed against moisture) and the center conductor of the coax connected just like a long wire (the center conductor is pushed into the center socket on a SO239 connector. Make sure the braid is floating (not touching anything) and not connected to anything at the station end.


     Whenever a balanced load like a dipole is connected to a
unbalanced load like coax, we insert a gadget called a BALUN. It's fairly obvious where the name comes from: BALanced to UNbalanced. The basic idea in its use is to be sure that the RF current goes into the antenna and not back down the outside of the coax. Did you ever hear of a ham complaining about RF in the shack? Or, getting a shock off the mike? This was probably some of the RF getting on the outside of the braid of the coax and becoming a problem.

     One of the problems with the RF on the outside of the
braid is the effect it has on the antenna radiation pattern.
The coax becomes part of the antenna and radiates at cross
purposes to the main part of the antenna. This distorts the
pattern and can cause for a ham's life to be miserable.

     Gather around and let's get down and dirty solving the
problem. Let's make a BALUN! A quicky solution that will
probably work is to start with 18 to 21 feet of RG8 type coax
and wind it on a PVC pipe of 3 to 5 inches in diameter.  This
will likely do the job for everything between 160 and 10
meters. (No guarantee.)  The secret is the 18 to 21 feet of
coax not the diameter of the pipe.  Make sure to use coax
that has a solid and not foam dielectric.  Try to make the
turns close wound and in a single layer. If you scramble wind the input and output ends of the balun, the ends could be too close together and cause difficulty.
    If you would like to do a single band balun, the
following chart has been suggested by some amateurs.

Mhz       RG-213,RG-8                   RG-58
3.5        22 FT, 8 turns                20 FT, 6-8 turns
7           22 ft, 10 turns                 15 ft, 6 turns
10         12 ft, 10 turns                 10 ft, 7 turns
14          10 ft, 4 turns                    8 ft, 8 turns
21            8 ft, 6-8 turns                 6 ft, 8 turns
28            6 ft, 6-8 turns                 4 ft, 6-8 turns

     This article is the result of reading of the "UGLY BALUN" available on the web. Look up the article and examine the pictures of baluns that were sent in to the author from other amateurs.

While working at a pizza parlor I observed a man ordering a small pizza to go.                He appeared to be alone and the cook asked him if he would like it cut into 4 pieces or 6.       He thought about it for some time               before   responding.                                                   "Just cut it into 4 pieces; I don't think I'm hungry enough to eat 6 pieces."
Yep, They Walk Among Us!

While looking at a house, my brother asked the real estate agent which direction was north because, he explained, he didn't want the sun waking him up every morning. She asked, "Does the sun rise
in the North?" When my brother explained that the sun rises in the East, and has for quite sometime, she shook her head and said, "Oh, I don't keep up with that stuff."

They Walk Among Us !!

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