[Elecraft] K3/KPA500 VSWR on 6m

[Don Wilhelm]

Jack,

I am sorry to hear that you had problems with the twisted pair wire.

Normally twisted pair makes a very effective and self shielding 
transmission line, even at 6 meters.
The characteristic impedance does depend on the diameter of the 
conductors and the thickness of the insulation separating the two 
conductors.

I am glad that you had success with your RG-58 substitution, but I 
believe there was some other condition present that your substitution 
corrected.

73,
Don W3FPR

On 11/17/2015 5:55 PM, wa9fvp wrote:
> I remember when I was building the KPA500 that there was a 4" twisted wire
> from the PA board to the RF out jack.  A short twisted wire as a
> transmission line on the HF bands is probably OK but On 6 meters, the
> inductance in twisted wire, I'm sure, will exhibit loss.
>
> I replace it the wire with a 4" length of RG58U.  Now all 3 SWR readings
> agree and the VSWR is 1.1:1.
>
>