Differences

This shows you the differences between two versions of the page.

--- oarc-sota-day-antennas [2022/05/31 22:40] – [VHF/UHF Antennas] mm3iig
+++ oarc-sota-day-antennas [2022/05/31 22:40] – [Slim Jim] mm3iig
@@ Line 36: / Line 36: @@
 Popular vertical antennas include coax dipole types, 1/4 ground plane antennas with some radials, or j-pole/Slim Jims made from ladder line. A mast of some kind is useful to get them up high for better line of sight to the horizon.
-==== Slim Jim ====
+=== Slim Jim ===
 A Slim Jim is a small, robust, roll up antenna that can be bought ready-made or [[https://m0ukd.com/calculators/slim-jim-and-j-pole-calculator/|easily home made]] from ladder line, a length of coax and a connector for your radio. The default velocity factor on the calculator page is for bare copper which is too high for insulated ladder line - 0.8 to 0.89 is a closer estimate. The feed point can be weak so either make sure it is aligned with the centre support material or don't strip the insulation completely. Combined with an collapsible pole that can be strapped to a fencepost or supported on a ground spike makes for an effective - though single-band - antenna setup.