[Antennas] The big picture?

Sun Oct 3 19:43:19 EDT 2004

> The difference between a vertical with minimal radials and one optimized is 
> probably 3 dBi or less. Does that 3dBi make that much difference? Reason I ask 
> is looking at the bands with a spectrum analyzer / scope you can see lots of 
> garbage (noise) and 3 dBi does not seem to be very significant. On the old 
> S-meter it is a bit less than half a unit. Is the lobe pattern and angles more 
> significant?? 

 My HAM club, AReU in Brandon FL, did a "far field" antenna evaluation 6 or 7 
years ago on 40 meters. The reference antenna was three 10 foot long aluminum 
`down spouts' screwed together es positioned on a polyethylene pop bottle as a 
base insulator es guyed at the top only. We had an aluminum radial ring with 32 
small machine screws to connect the radial wires to. When we went from 4 to 8 
radial wires (32 feet long) the far field signal strength went up 3 db. When we 
went from 8 to 16 radial wires (32 feet long) the far field signal strength went 
up 3 db. I could not convince the body to try 32 radial wires, I wanted to 
know, but it was assumed no HAM would go that far. I still want to know.
Most mobile antennas were down 10 dB even with the 16 radials under the bumper. 
(and connected) Every antenna was positioned where the reference antenna was 
mounted. All antennas tested transmitted. The results were never published.
-- 
 73 (= Best Regards) de: Ron ka4inm at tampabay.rr.com
 100% LINUX, since July, 1997 SENT Time and Date are UTC
 Visit my HAM Web SITE at: http://www.qsl.net/ka4inm