The connectors are labeled properly to match a transmitter to a higher
impedance. This is the normal connection. To match impedances that are lower than your transmitter impedance (such as a mobile whip), simply interchange the normal transmitter and antenna connections to the MFJ-16010.
Remember the MFJ-16010 is designed to match a single random wire and not a
coaxial line, even though coaxial connectors are used for both antenna and
transmitter connections (these connectors make it easy to interchange antenna
and transmitter connections).
A standard banana plug will fit nicely into the center of the SO-239 coaxial
connector and can be used to connect the single random wire in lieu of a
coaxial plug (PL-239).
A standard coaxial cable having an impedance that matches your transmitter
output impedance, should be used to connect your transmitter to the
MFJ-16010 Random Wire Antenna Tuner. Make sure the MFJ-16010 is well grounded to the transmitter.
If you are using the MFJ-16010 to match a vertical or mobile whip, the tuner needs
to be at the feed point of the antenna and not at the transmitter end of the
coaxial transmission line.
The MFJ-16010 Random Wire Antenna Tuner is small enough to carry in your hip pocket (2 x 3 x 2 inches).