View Single Post
 
Old 05-02-2016, 12:30 AM
spacecase0's Avatar
spacecase0 spacecase0 is online now
Senior Member
 
Join Date: Nov 2014
Posts: 387
remember that is the 3 meter band you are working with,
and the ground is not the same from one place to the next,
so you are going to have to run some tests as to what the velocity factor of your ground is
after you get that number,
this might help you figure that out Velocity Factor - K3DAV.com - Amateur Radio Operator
found this on a google group
"Soil also has a propagation velocity. Of the order of VF = 0.15 at HF. "
from https://groups.google.com/forum/?_es...na/Sy1LCZSbNag
and with the number so low and your frequency so high,
I would likely just make a dipole antenna that I could just entirely put underground (vertical orientation would likely work best)
so each 1/4 wave wire needs to be 3M times 1/4 times 0.15
should be about 0.1125 meters long for each half, but that will change with your soil (and likely how much water it has in it at the moment),
and for anyone that does not know what a dipole antenna is, try this
Dipole Antenna | Dipole Aerial Theory | Tutorial
and I would think you would rather have pictures of my sister wearing a corset
not sure it matters to much what you make the antenna out of, as long as it will not corrode in the ground and conducts electricity
__________________
 
Reply With Quote