dykesc wrote:
I need to calculate
total line losses based on SWR readings without the transmatch in the
line.

If your feedline between the transmatch and the antenna is
50 ohm coax, you can leave the transmatch in the system and
use a separate SWR meter on the output of the transmatch to
measure the SWR on the coax between the transmatch and the
antenna.

If you don't have 50 ohm coax between the transmatch and
the antenna, you are SOL in determining the actual SWR on
the ladder-line or whatever with a standard SWR meter. The
50 ohm SWR reading without the transmatch is completely
different from the actual SWR on the transmission line when
the Z0 is not 50 ohms.

Even the SWR reading looking into ladder-line using an
MFJ-259B is nowhere near the actual SWR on the ladder-
line. For instance, a 50 ohm SWR meter can read a 1:1
SWR on 450 ladder-line when the actual SWR on the ladder-
line is 9:1.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com