Topband: inverted L issues

[ALEXEY OGORODOV]

 Hello,

Right to the point.  At HD2A we installed an Inverted L with the following dimensions:
vertical portion 16m
horizontal portion 26m.

The horizontal wire goes with slightly upward with with its end at 19m above the gound.
The ground system - 4 x 6ft ground rods at the base
                                     - 34 x 42odd m radials on the ground
No matching device is used. Fed directly with RG8 coax.
The SWR was at 1.5 to 1.8  on 1.832 now it is 3:1 at the same frequency with no visible alterations to the antenna except the rain season.

The question: what could cause the SWR increment? any suggestions to bring it down and keep it relatively stable.

Thanks in advance,
Alberto, Alex
HD2A Team