[TowerTalk] Capacitor Value for a 160m T antenna

[Mike Fahmie]

If you are only concerned with tuning out the inductive reactance, a series capacitor can be chosen for that purpose.  The resulting Z of the antenna then becomes 41.2Ω +j0 and the SWR drops from about 12:1 to about 1.2:1.
The equation is derived from the formula for capacitive reactance:  Xc = 1/(2*Pi*F*C)Solving for C, the equation becomes:  C = 1/(2*Pi*F*Xc).
If F = 1.9 MHz and Xc = 139Ω, then C = 603 pF

Don't ignore the voltage across this capacitor, for a KW, that voltage will be the better part of a kilovolt
-Mike-WA6ZTY

 
      From: Richard Thorne <rthorne at rthorne.net>
 To: Towertalk <towertalk at contesting.com> 
 Sent: Monday, November 7, 2016 9:48 AM
 Subject: [TowerTalk] Capacitor Value for a 160m T antenna
   
I'm going to build a T antenna for 160 in a few weeks.

I need a capacitor to tune out z = 41.2 + j139.

For the educational experience, how do I calculate a cap for the above 
equation?  I'm going to try and track down a variable cap for the above 
so I can build the antenna over the Thanksgiving holiday.

Thanks

Rich - N5ZC

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk