Roy Lewallen wrote in
:

....
The shield has an impact on the differential mode impedance, but it
doesn't help line balance or provide shielding at all.

Roy,

I quite agree with you.

I have received a third hand comment that something in my related article
at http://www.vk1od.net/transmissionline/stcm/index.htm is incorrect. I say
something because there is a language translation involved in the third
hand process.

Have you read the article, and have you any issue with it?

Thanks
Owen