Shunt loads on T-lines in EZNEC
 

On my web page at: http://www.w5dxp.com/G5RV.HTM
I show how to install a 1000 pf capacitor across
the G5RV transmission line at the twinlead/coax
junction to improve the 75m SWR and move the
resonant point into the 75m phone band.

I have never been able to model the shunt capacitor
with EZNEC. Anyone know of a way to do that?
--
73, Cecil http://www.w5dxp.com

Shunt loads on T-lines in EZNEC
 

On Oct 15, 2:55?pm, Cecil Moore wrote:
On my web page at:http://www.w5dxp.com/G5RV.HTM
I show how to install a 1000 pf capacitor across
the G5RV transmission line at the twinlead/coax
junction to improve the 75m SWR and move the
resonant point into the 75m phone band.

I have never been able to model the shunt capacitor
with EZNEC. Anyone know of a way to do that?
--
73, Cecil http://www.w5dxp.com

Hi Cecil, Looking at your webpage, looks to me like a 103' dipole
with 36-j324 impedance at 3.8 Mhz needs 28' of 450 ohm line instead of
300 ohm. 28' of 450 ohm line put you at 24+j25 with an swr of 2.7:1.
1000pf shunt cap. puts you near 1:1.

As for modeling the Shunt Capacitor, I have never done it, but you
might try a stub to simulate the Xc. Don't have time at the moment,
or I would give it a try.

73 Gary N4AST

Shunt loads on T-lines in EZNEC
 

wrote:
Hi Cecil, Looking at your webpage, looks to me like a 103' dipole
with 36-j324 impedance at 3.8 Mhz needs 28' of 450 ohm line instead of
300 ohm. 28' of 450 ohm line put you at 24+j25 with an swr of 2.7:1.
1000pf shunt cap. puts you near 1:1.

I wasn't trying for perfection, just improvement. I actually
tried it on my G5RV and got considerable improvement in reality.

As for modeling the Shunt Capacitor, I have never done it, but you
might try a stub to simulate the Xc. Don't have time at the moment,
or I would give it a try.

That's a good idea, Gary, thanks for the suggestion.
--
73, Cecil http://www.w5dxp.com

Shunt loads on T-lines in EZNEC