Some notes,
So far, tuning is similar to, but not exactly like the East/West (EW) antenna.
Here's how they differ in configuration:
- The NS runs more like an L antenna than the EW. The far end of the NS does drop down about 6-8 feet but it finishes its drop significantly higher than the EW.
- The NS Feedline has 1 extra bend in it. It goes up from the tuner, bends to the eave, and chicanes out of the soffit into the sky at about a 60-70 degree angle. The EW antenna only has one chicane out of the soffit, and goes up at about a 60-70 degree angle.
- The EW runs flattish (sag in the middle, but not enough to count) at height. See My "Yearly W3EDP Antenna Post" for a diagram of the shape of the antenna. The NS gets to a little below the height of the EW and slopes up to significantly higher than the EW antenna. I'm not able to precisely determine the difference as the far end of the NS antenna isn't very accessable.
- The NS antenna touches the tree it's mounted in at the far end. This probably plays the single biggest role in changing the impedance of the antenna. I tried to keep it off the limb, but can't because of where I can mount it. It was pull the far end over a limb, or cause the feedline and antenna to orient at an acute angle.
Sighting up the Wire |
Close on the feedline |
Transition from Feedline to Antenna |
The Thin White Line about midframe is the Antenna |
#FAIL
construction notes:
both EW and NS are exactly alike, the wire came from the same length of Wireman #523 ("Silky" see http://www.thewireman.com/antennap.html), the "Feedline" section came from the same roll of Wireman #553, both antennas use banana plugs from the same Radio Shack, and they both use Army pants buttons for the end insulators. I made them both the same night, to sell at a conference. The EW has been deployed longer, but the wire is still bright and has weathered well.
No comments:
Post a Comment