[Antennas] Change in coaz = change in SWR.

George, W5YR [email protected]
Sat, 26 Oct 2002 20:55:05 -0500


Try at least two other SWR meters before doing anything.

Sounds like you have changed from a relatively lossy coax to one with less
loss. That will cause the indicated SWR to increase. Also, if you are not
using a 1:1 current balun at the antenna feedpoint, you can have
common-mode current affecting the SWR/analyzer reading.

What type of antenna?

73/72, George    
Amateur Radio W5YR -  the Yellow Rose of Texas
In the 57th year and it just keeps getting better!
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
K2 #489      Icom IC-765 #2349     Icom IC-756 PRO  #2121


Thomas Beltran wrote:
> 
> I exchanged 100' feet of RG-58 with 100' of Cable X-Perts 1318FX.  After
> checking the SWR with an RF-1, there is quite a difference - the resonant
> frequency of the antenna has gone up around 600 khz.  For example, I had a
> 1.7:1 (checked just before changing the coax) at 14.230.  Now that freq
> shows an SWR of  4:1.  The low point, 1.3:1, is at 14.880.  Before adjusting
> the antenna, I thought I would check with the people on this list.  Any
> ideas?  Tom W6EIJ