> What antenna is shown on the KX3 photo. It is mounted on a 90 degree
> BNC adaptor.
Careful if you mount the whip antenna directly at the KX3 (or other transceivers).
The force that the 1.4 m long antenna exerts on the BNC socket of the transceiver is not
negligible, especially if wind blows. It's better to use a short piece of koax cable as
flexible connecting piece and put the antenna on a separate stand.
I've used the MFJ telescoping whips successfully with my KX1 on 20M and
40M. Of course, they don't perform as well as a good random wire slung
over a tree with a counterpoise (using a BNC to 2-terminal adapter), but
that option doesn't work when there are no trees available . or if
you're in a hotel room with sealed windows. I've had good QSOs, indoors
as well as outdoors, with a whip mounted directly to the KX1 with a
right-angle BNC adapter, and a counterpoise attached to the bottom
thumbscrew. And it became more versatile and less cumbersome when I
made a base for the telescoping whips, which is just a female BNC with a
run of RG174 mounted on an aluminum plate that also has a few
thumbscrews for attaching radials. The base mounted whips work well
when there are no trees available . and even inside Hotel rooms.
The MFJ whips, when attached to my homemade base, test out well with an
SWR analyzer. The resonant points are around 1.2:1. So I plan to use
the same antennas with my KX3 if it ever arrives!