View Single Post
  #2   Report Post  
Old June 20th 10, 04:35 PM posted to rec.radio.amateur.antenna
Ralph Mowery Ralph Mowery is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 702
Default Tapering open wire feedlines?


"Pete Bertini" wrote in message
...
Just curious if this has ever been done? I'm thinking about
putting up a 90 foot dipole feed with homemade open wire
line. I'd like to bring it into the shack using paralled runs
of LMR-400 cable, since the final 25 feet is via 3" electrical
conduit that also has rotor and other cables.

I believe the parallel cables with give me a 100 ohm impedance.
The open wire will be using #10 with homemade spreaders,
I'm going to try for 600 ohms at the feedpoint. I was wondering
if tapering the spacing on the feedline would give me a smoother
impedance where the open wire, arrestor, and twin coax arrange-
meet?

Pete k1zjh


You have just reinvented the Delta Match.

http://www.g4nsj.co.uk/delta.shtml

Is one place to look.