View Single Post
  #5   Report Post  
Old October 21st 04, 09:45 AM
starman
 
Posts: n/a
Default

Brian wrote:

The antenna I had up before I moved was end-fed at the 9:1 transformer,
ground point. Would moving the feed-point, ground, transformer closer
towards the middle of the antenna have any negative effects, or effects at
all? My new residence would accomodate this orientation better. By the way,
I found a cool shop called Communication Headquarters right down the street
that has a ton of radio gear, yay!

-Brian


As you move along the wire the impedance changes. Moving the feedpoint
to some other location could result your 9:1 balun being less efficient
(mismatched). There are antennas which use a feedline connected to some
point along the wire instead of the end but you have to make the
connection at a specifc location, not just anywhere. The 'Windom' is one
of these types. The following website shows the design of a basic Windom
antenna. Note that the balun is 4:1 instead of your 9:1 for the end fed
wire. This is because the impedance at the connection point for a Windom
is lower than the end of a random wire or inverted-L.

http://www.packetradio.com/windom.htm


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---