[Antennas] why is this?

[RB]

I was fiddling around with my ant and tuner setup this pm.  I have a 140' dipole fed with approx 75' of 450 ohm ladderline.  I normally run a 1:1 choke balun to go from the unbalanced tuner to balanced feedline.

I got a surprise and seemingly illogical data when I swapped a 4:1 current balun in place of the 1:1 choke balun.

The first table below gives readings for the 1:1 choke balun.  The next table gives readings for the 1:4 current balun.  

Supposedly the 1:4 balun should give better results.  But, the data make it seem just the opposite.  So, curiosity is compelling me to ask if you guys see anything amiss here, and the associated cause.  My rig is capable of kicking out 100 watts CW.  That power output level is what the below measurements were made at::

                            1:1 (choke balun)

FREQ        LOAD         SWR
                 POWER

1,8            ----               ----         (no match point)
3.9            100              1.6:1
7.2            15                1.7:1
14.2           100              1.2:1
21.3           100              1.6:1
29.5           100              1.5:1


                               1:4 (current balun)

1.8              ----                ----           (no match point)
3.9              ----                ----           (no match point)
7.2              ----                ----           (no match point)
14.2            100               1.2:1
21.3            ----                -----           (no match point)
29.5            ___               ___          (no match point)