[TowerTalk] Johnson matchbox with coax feed line ?

[Robert Harmon]

I know the Johnson matchboxes have limited range, can’t use on the WARC bands for instance, and they 
are designed primarily for balanced feebleness, but how do they perform using unbalanced coax fed antennas ?
The Johnson KW matchbox has a SO239 on the back for using coax in addition to the balanced feed line connectors on the back.
Anyone use the Johnsons for coax antennas ?  How well does it work ?

thanks,
Bob
K6UJ