the important thing about the choke is not really the number of turns, but the length of cable used to get the turns.
here is a very intuitive link on choke baluns:
BUILD AN AIR WOUND 1:1 CHOKE BALUN FOR HF - THE UGLY BALUN!
in this article, they will tell you that you need 18-21 feet of length in your "coil", but that is for 1-30mhz.
you are only interested in 26-28mhz roughly, so all you need is around 8-10 feet of length in your coil.
now, since you are using RG8 coax, you need to be sure not to wrap it around anything too small in diameter or you risk changing the impedance of the coax by squeezing the shield and the center conductor close together.
i would not use anything less than 4" in diameter. preferably 6" in diameter.
this will come out to about 6-8 turns on your coil form, whatever that may be. (just dont use anything metal or wood)
also, there is something about mounting your dipole vertically that i dont think has been mentioned here yet.
that is, the coax must leave the dipole at a 90* angle from the elements for at least the first 8-9 feet. (1/4 wavelength at 11 meters)
that means that if you mount the dipole vertically, you must run the coax horizontally away from the antenna for the first 8-10 feet before you can run it down to the station.
running the coax parallel with the bottom leg of the dipole will mess up the pattern.
this is why you see most dipoles mounted horizontally. to take advantage of the coax coming straight down from the antenna while still being perpendicular to the antenna elements.
when running a barefoot station, you need all the help you can get from your antenna system.
as has been mentioned before, if you want to talk locally most of the time, you should consider mounting the dipole vertically, as mounting it horizontally will attenuate all the signals coming in from the mobiles and vertical antennas in your area.
if, however, you want to talk skip most of the time, mount it horizontally, as skip signals change polarization all the time and rarely hit you exactly vertical or horizontal.
also, if its convenient at all, a neat thing to do is to mount your mast in a way that allows you to turn the mast different directions.
this way, if you want to talk north south primarily, you can turn it that way, and if you want to talk east west primarily, you can turn it that way.
there are many ways to do this, as im sure you can picture.
the best advice i can give you is to get it up in the air and mess with it before you try to finalize everything, as you will undoubtedly have to change something that you thought you would not have to change.
thats just the way it goes,
good luck,
LC
here is a very intuitive link on choke baluns:
BUILD AN AIR WOUND 1:1 CHOKE BALUN FOR HF - THE UGLY BALUN!
in this article, they will tell you that you need 18-21 feet of length in your "coil", but that is for 1-30mhz.
you are only interested in 26-28mhz roughly, so all you need is around 8-10 feet of length in your coil.
now, since you are using RG8 coax, you need to be sure not to wrap it around anything too small in diameter or you risk changing the impedance of the coax by squeezing the shield and the center conductor close together.
i would not use anything less than 4" in diameter. preferably 6" in diameter.
this will come out to about 6-8 turns on your coil form, whatever that may be. (just dont use anything metal or wood)
also, there is something about mounting your dipole vertically that i dont think has been mentioned here yet.
that is, the coax must leave the dipole at a 90* angle from the elements for at least the first 8-9 feet. (1/4 wavelength at 11 meters)
that means that if you mount the dipole vertically, you must run the coax horizontally away from the antenna for the first 8-10 feet before you can run it down to the station.
running the coax parallel with the bottom leg of the dipole will mess up the pattern.
this is why you see most dipoles mounted horizontally. to take advantage of the coax coming straight down from the antenna while still being perpendicular to the antenna elements.
when running a barefoot station, you need all the help you can get from your antenna system.
as has been mentioned before, if you want to talk locally most of the time, you should consider mounting the dipole vertically, as mounting it horizontally will attenuate all the signals coming in from the mobiles and vertical antennas in your area.
if, however, you want to talk skip most of the time, mount it horizontally, as skip signals change polarization all the time and rarely hit you exactly vertical or horizontal.
also, if its convenient at all, a neat thing to do is to mount your mast in a way that allows you to turn the mast different directions.
this way, if you want to talk north south primarily, you can turn it that way, and if you want to talk east west primarily, you can turn it that way.
there are many ways to do this, as im sure you can picture.
the best advice i can give you is to get it up in the air and mess with it before you try to finalize everything, as you will undoubtedly have to change something that you thought you would not have to change.
thats just the way it goes,
good luck,
LC
