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#1
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80M antenna Help
I need plans for a quick, easy to build, reasonable efficient 80m antenna. I
have very limited space. Any ideas will be considered. I possible, email them to me at . Randy ka4nma |
#2
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Randy,
How much space do you have? Kind of hard to get an idea of what may work for you without knowing that. 'Doc |
#3
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#4
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Take a wire through your radio shack window up to the top of a pole on your
house chimney. Extend the wire from the top of the pole to a tree or other high support. Make the wire as high and as long as you can. It is known as an Inverted-L. To increase overall length the end of the wire can be further extended sideways or downwards towards the ground. This will be most efficient, all-band, all-direction, all elevation antenna which is possible in your back yard. ---- ======================= Regards from Reg, G4FGQ For Free Radio Design Software go to http://www.g4fgq.com ======================= |
#6
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"'Doc" wrote -
Dang Reg, how did you know what his backyard looks like?? 'Doc ---------------------------------------------------- Randy said - " I need plans for a quick, easy to build, reasonable efficient 80m antenna. I have very limited space... " ---------------------------------------------------- Dear Doc, The key words in Randy's frantic appeal for help were QUICK, EASY, REASONABLY EFFICIENT, 80m, LIMITED SPACE. My response fits the bill exactly. It is the concise, accurate, reply which I would have expected from your good, practical self. The key words in my response were contained in the last sentence. For your benefit I repeat - "This will be the most efficient, all-band, all-direction, all-elevation antenna which is possible in YOUR BACK YARD." A coloured photograph with an ordinance survey map of his back yard, showing his domestic and nearby buildings with trees and overhead power and phone lines, with a cross to indicate the position of his shack window, are not necessary to satisfactorily comply with Randy's brief, very common requirements specification. You may rest assured my suggestions apply to ANYBODY's small back yard. Read them again. The foregoing is for the benefit of novices and other lurkers. It should be included in all editions of ARRL and RSGB publications. You just forgot to include a smiley in your message. ;o) ;o) ------------------------------------------------- Incidentally, I am accustomed to changing my antennas fairly frequently. Never had a permanent installation. My present recent antenna is an 18-gauge enamelled wire which extends from the ground-floor kitchen window, up the wall of the house, to a 10-feet mast affixed to the house chimney above the apex of the roof. Overall height is about 40 feet. It is bottom tuned. There are two ground radials. One radial consists of the domestic incoming metal water pipe and is about 5 miles long. It is also connected to all the other 100 thousand water pipes in the area. The second radial is a fairly useless 12 feet long wire, connected along the soil surface to a 2-feet earth rod in the garden soil. Resulting measured ground loss resistance is about 15 ohms on the 80m band. So much for Marzipan the Magician's magic number of 120 as plagiarised by the magazine guru's. Athough I have considerably more real estate it is what I would refer to as a very small backyard antenna. With 100 watts it will keep me happy on 160, 80, 40, 30 and 20m although, sooner or later, I MIGHT have a complaint from the next door neighbour about TV interference on the higher frequencies. His TV antenna coax down-lead is about 25 feet from my 'vertical' wire and he has 3 TV receivers connected to his antenna, from one room to another via an amateur electrician's coaxial ring main. He will notify me of a problem by means of a heavy hammer on the adjoining wall. He's that sort of person - considers himself to be the local Mafia Godfather. He's 83 years of age, waiting for a hip operation, but claims to have a step-son employed in a local firm of legal solicitors. However I have reason to believe his step-son is just the inter-office message and tea/coffee boy. You fortunate, cheap gasoline, USA citizens, with vast antenna farms, don't have the foggiest idea of what life is like for us mini-backyard denizens inhabiting the rest of this over-populated world, wondering from where the next scrap length of enamelled, annealed, copper magnet wire is coming from. And if anybody thinks I'm just pulling your lazy legs - for once you are right on the ball! ;o) To estimate the L and C values of a home-brew tuner, suitable for any small backyard vertical or inverted-L wire, download in a few seconds program ENDFEED from website below and run immediately. A 3-weeks training course not needed. Regards from Reg, G4FGQ. ======================== For Free Radio Design Software, made in the Black Country, near the original Birmingham, England, go to http://www.g4fgq.com ======================== |
#7
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Reg, As Gomer used to say... "Shazzaam!" 'Doc |
#8
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Hi Doc and Reg,
I live in a 2 story historical house with a hill and 4 story house in the back. On one side is a large 2 story house. The road is in front, only about 15-20 feet away. The only remaining side has a cottege and parking lot with a single tree about 30 or 40 feet away. I have very close power and cable tv lines on 3 sides of the house. On 2 sides, including the side where the radio shack is, we have 2 propane gas lines (one for hot water, the other for the heater). Did I mention the owner cemented all the land and installed raised flower beds? The nearest run to a ground would be from the wall about 5 feet to a flower bed. The good news is that I have no antenna restrictions in the lease and actually the landlord said antennas were OK! I am thinking of mounting a DK3 screwdriver on a tripod, and when I want to operate, move it to the parking area, and then move it back when done. Not quite sure how to mount it on a tripod. Any advice? For 20m & 17m I have Par Electronics end feed hertz, which could be run to the tree. Randy ka4nma |
#9
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