GerryS wrote:eamarquardt wrote:
If you know what a yagi is I suspect you know the upsides and downsides of antennas. Try a longwire and see what happens. TV signals are horizontally polarized so a vertical antenna isn't going to be optimal.
Cheers,
Gus
AB6KS
I know horizontal polarization....it would be nice to us shoot a line into the tree, like I do wuth my 2 meter j-pole....but that isn't possible....
I know enough about antennas to know I don't know crap about antennas... I was thinking about a dipole between trees, but I haven't a clue what length(s) or how to connect it to coax.
Experiment. SWR/impedance match probably isn't as important on receive as it is on transmit. Just connect the center conductor to one side of your dipole and the shield to the other. Mount your dipole on a thin board with a bridal so you can hoist it up and keep it horizontal.
Here are the frequencies. You might want to build several dipoles to match the different bands or even portions of the bands.
http://en.wikipedia.org/wiki/North_Amer ... requenciesHere's a calculator for converting MHz to wavelenght:
http://www.unitconversion.org/frequency ... rsion.htmlEach element of your dipole should be 1/4 wavelength long.
According to:
http://members.tripod.com/martin_leese/ ... erial.html"There are two forms of half-wave dipole. A simple half-wave dipole has an impedance of about 75 ohms and is just two bits of wire of an appropriate length. I use a "bunny ears" TV antenna with the ears adjusted to be in a straight line.
A folded half-wave dipole has an impedance of 300 ohms and is made from 300-ohm twin-lead with the ends shorted. You can buy these very cheaply."
So for a simple dipole no balun is required. If you want to build a folded dipole (more complicated) matching baluns/transformers 300ohm/75ohm are easy to find on EBay:
http://www.ebay.com/itm/4-New-75-Ohm-to ... 35c704a190The materials are cheap. A big part of the experience is making your own. Even a 3 element yagi would be easy to make and hoist. There are lots of sites with details on how to construct yagis.
With antennas, bigger and higher is more betterer.
Hope this helps.
Cheers,
Gus
AB6KS
The opinions in this post are my own. My comments are directed to those that might like an alternative approach to those already espoused.There is the right way,the wrong way,the USMC way, your way, my way, and the highway.
"I'm impatient with stupidity. My people have learned to live without it." Klaatu-"The Day the Earth Stood Still"
"You can't handle the truth!"-Jack Nicholson "A Few Good Men"
"Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem"-Ronald Reagan
by GerryS » Sun Apr 28, 2013 6:32 pm 
) You can get them at any truck stop/travel center. It has all the mounting hardware to go on a truck mirror or horizontal pole of some kind. mine even has a pass through for a cb antenna.
