"Helmut Wabnig" .... .-- .- -... -. .. --. @ .- --- -. dot .- - wrote in
message ...
On Fri, 14 Sep 2007 16:17:42 -0500, "amdx" wrote:

I've posted a picture on alt.binaires.schematics.electronic
to an effort to help me get a better understanding of an antenna.
It is a 2.4Ghz antenna about 18" long
The driven element is a copper ribbon 0.2" wide by 0.032" thick.
The copper ribbon forms a loop about 2" wide by 0.625" tall.
The gap in the ribbon would be 0.020", but note; in the pictures
a moon shaped piece has been cut from both ends. I think this

yes, it was made on a moonday.

moon cut effectively make the gap look larger.
The total coax length is 2.350", the shield a bit shorter at 2.08".
There are 4 toroids on the coax. These are under a piece of heat
shrink, so I have no idea what material they would be.
All element spacings are all equal and element lengths are within
.030" of each other. I think they were designed to be the same but
manufacturing tolerances made the differences. The reflector is longer.
So now what can the group tell me about;
Driven element impedance
the gap
coax length impedance transformation


the 4 toroids
noise reduction ferrite beads or toroids
Line filters get rid of RF travelling along the outer surface of the
coax's shield and avoid, consequently, any TVI/BCI. The best
performance can be seen when connected right into the feed line at the
antenna base!




Thanks for the help, if you need any other details let me know.
Mike

hard not to be cynic.
w.
Do you mean a cynic, as in ;
a faultfinding captious critic; especially : one who believes that human
conduct is motivated wholly by self-interest.
Well yes, I ask the questions because (I) want to know, but if someone
else learns from the answers, I don't care.
"Moonday" hurumpf ;-}
Mike