View Single Post
  #2   Report Post  
Old November 26th 12, 01:39 AM posted to rec.radio.amateur.antenna
W5DXP W5DXP is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2011
Posts: 182
Default Connecting built in antenna tuner to ladder line.

On Sunday, November 25, 2012 4:08:00 PM UTC-6, Tom W3TDH wrote:
Thank you in advance to all who choose to tackle this question.


Assuming your folded dipole is a resonant antenna with a feedpoint impedance around 300 ohms, with a 1:1 balun, the 50 ohm SWR would be 300/50=6:1 and that is probably outside the range of most built-in autotuners. Assuming a 300 ohm feedpoint impedance, a 4:1 balun would bring the 50 ohm SWR down to 75/50=1.5:1. 4:1 baluns are inexpensive so I suggest a 4:1 balun as a first try. You might get by with the less expensive 4:1 voltage balun but I recommend a 4:1 (dual-toroid) current balun.
--
73, Cecil, w5dxp.com