Re: How do I best operate a 4S-Tuner with a Doublet antenna ?


Frank Perkins <N6CES.r@...>
 

Hi Bob,
What you have should work fine.
After I read your attached article, I discovered it's not a standard 40 meter  dipole.
Your feedline type alters the dipole design to allow a shorter leg length, and allow multiband performance.
You should get results attaching the feedline do the tuner, and probably some improvement with the 4 to 1 BALUN.
Cheers,
Frank N6CES



On Sat, Apr 13, 2019, 10:03 PM Frank Perkins via Groups.Io <N6CES.r=gmail.com@groups.io> wrote:
Hi,
At only 22ft per leg, sounds like you might have a 30 meter dipole, resonant around 10 mHz.
Adding a 4 to 1 BALUN will take the balanced feedline to balanced 50 ohms to enter your tuner.
Frank N6CES

On Sat, Apr 13, 2019, 7:23 PM Bob KM6BMX <km6bmx@...> wrote:
Hello, 

  I plan to operate my 4S-Tuner with a 40m "Doublet" antenna.  The doublet has two 1-wire legs, 22 feet each, with a 28 foot 2-wire feedline, which I assume is "balanced". (See URLs below for details). 
 
  I have 2 questions. 
 
    I recently re-read the manual, which states the following:  "With an external balun it will also match antennas with balanced feedlines."  However, there are 2 binding posts that share the same internal circuit connection as the output BNC connector ("ANT"). 
  
  Q1:  Can I just connect the "balanced" 2-wire feedline directly to the posts, picking one as the "antenna" and the other as "ground"? 
  
  On a related note, it seems that the 4S-Tuner is geared primarily towards high-impedance antennas, such as EFHW. 
 
  Q2:  How does it perform with an antenna with an impedance close to the nominal 50 ohms? 
  
  Thanks much for your insights!
 
Cheers & 73,
Bob KM6BMX  
--  central AZ
  
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    NorCal "Crappie" antenna 
  
NorCal "Doublet" antenna
 
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